plans: correct extraction note — declined after reading both impls

Reading lib/mod (Prolog) and lib/acl (Datalog) side by side shows the convergence
is in module names only. Federation: opposite trust models (SX registry + decision
sharing vs in-engine Datalog trust facts + fact replication), zero shared code.
Audit: only a ~5-fn core overlaps and it diverges (entry shapes, seq base 0 vs 1,
op sets, mutation idiom) — not worth a shared module under two restricted envs.
Outcome: keep them parallel; revisit only on a third same-model consumer.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.claude/scheduled_tasks.lock

@@ -1 +1 @@
-{"sessionId":"31c80255-eb92-43e4-8997-84ad84e27326","pid":90960,"procStart":"564684","acquiredAt":1777049890282}
+{"sessionId":"bf20a443-9df8-4cb9-932e-8c6f4c4625c2","pid":1303602,"procStart":"253831081","acquiredAt":1779865895644}

.mcp.json

@@ -2,7 +2,7 @@
   "mcpServers": {
     "sx-tree": {
       "type": "stdio",
-      "command": "./hosts/ocaml/_build/default/bin/mcp_tree.exe"
+      "command": "/root/rose-ash/hosts/ocaml/_build/default/bin/mcp_tree.exe"
     },
     "rose-ash-services": {
       "type": "stdio",

lib/erlang/runtime.sx

@@ -956,118 +956,8 @@
         (= ty "nil") (er-mk-nil)
         :else v))))
 
-;; ── HTTP request/response marshaling (Step 8b-start) ────────────
-;; The native `http-listen` primitive hands the handler an SX dict
-;;   {:method :path :query :headers :body}
-;; and expects an SX dict back
-;;   {:status :headers :body}
-;; This layer converts so Erlang handlers see proper proplists:
-;;   [{method, <<"GET">>}, {path, <<"/foo">>}, {query, <<>>},
-;;    {headers, [{<<"content-type">>, <<"text/plain">>}, ...]},
-;;    {body, <<...>>}]
-;; Headers ride as a nested proplist with binary keys — header names
-;; are arbitrary user input, so they stay out of the atom table. The
-;; outer request keys (method/path/query/headers/body) are fixed and
-;; small, so they become atoms (cheap to pattern-match against).
 
-(define er-of-sx-deep
-  (fn (v)
-    (cond
-      (= (type-of v) "dict") (er-dict-to-header-proplist v)
-      :else (er-of-sx v))))
 
-(define er-dict-to-header-proplist
-  (fn (d)
-    (let ((ks (keys d)) (out (er-mk-nil)))
-      (for-each
-        (fn (i)
-          (let ((idx (- (- (len ks) 1) i)))
-            (let ((k (nth ks idx)))
-              (let ((v (get d k)))
-                (set!
-                  out
-                  (er-mk-cons
-                    (er-mk-tuple
-                      (list
-                        (er-mk-binary (map char->integer (string->list k)))
-                        (er-of-sx-deep v)))
-                    out))))))
-        (range 0 (len ks)))
-      out)))
-
-(define er-request-dict-to-proplist
-  (fn (d)
-    (cond
-      (not (= (type-of d) "dict")) (er-of-sx d)
-      :else
-        (let ((ks (keys d)) (out (er-mk-nil)))
-          (for-each
-            (fn (i)
-              (let ((idx (- (- (len ks) 1) i)))
-                (let ((k (nth ks idx)))
-                  (let ((v (get d k)))
-                    (set!
-                      out
-                      (er-mk-cons
-                        (er-mk-tuple
-                          (list (er-mk-atom k) (er-of-sx-deep v)))
-                        out))))))
-            (range 0 (len ks)))
-          out))))
-
-;; Inverse: handler's proplist response -> SX dict for native send.
-;; Value rules:
-;;   Erlang binary   -> SX string (bytes joined)
-;;   Erlang integer  -> SX number passthrough
-;;   Erlang cons of 2-tuples -> nested SX dict (e.g. headers)
-;;   Erlang cons (other shapes) -> SX list via er-to-sx
-;;   anything else   -> er-to-sx passthrough
-
-(define er-proplist-2tuple?
-  (fn (v)
-    (cond
-      (er-nil? v) true
-      (er-cons? v)
-        (let ((h (get v :head)))
-          (cond
-            (and (er-tuple? h) (= (len (get h :elements)) 2))
-              (er-proplist-2tuple? (get v :tail))
-            :else false))
-      :else false)))
-
-(define er-to-sx-deep
-  (fn (v)
-    (cond
-      (er-binary? v) (list->string (map integer->char (get v :bytes)))
-      (and (er-cons? v) (er-proplist-2tuple? v)) (er-proplist-to-dict v)
-      :else (er-to-sx v))))
-
-(define er-proplist-to-dict
-  (fn (pl)
-    (let ((d (dict)))
-      (er-proplist-fill! pl d)
-      d)))
-
-(define er-proplist-fill!
-  (fn (pl d)
-    (cond
-      (er-nil? pl) nil
-      (er-cons? pl)
-        (let ((head (get pl :head)) (tail (get pl :tail)))
-          (cond
-            (and (er-tuple? head) (= (len (get head :elements)) 2))
-              (let ((kv (get head :elements)))
-                (let ((k (nth kv 0)) (v (nth kv 1)))
-                  (let ((key-str
-                          (cond
-                            (er-atom? k) (get k :name)
-                            (er-binary? k)
-                              (list->string (map integer->char (get k :bytes)))
-                            :else (str k))))
-                    (dict-set! d key-str (er-to-sx-deep v))
-                    (er-proplist-fill! tail d))))
-            :else (er-proplist-fill! tail d)))
-      :else nil)))
 
 ;; Load an Erlang module declaration. Source must start with
 ;; `-module(Name).` and contain function definitions. Functions
@@ -1578,26 +1468,9 @@
 ;; entry is keyed by "Module/Name/Arity"; multi-arity BIFs register
 ;; once per arity. Called eagerly at the end of runtime.sx so the
 ;; registry is ready before any erlang-eval-ast call.
-(define
-  er-bif-http-listen
-  (fn
-    (vs)
-    (let
-      ((port (nth vs 0)) (handler (nth vs 1)))
-      (cond
-        (not (= (type-of port) "number"))
-        (raise (er-mk-error-marker (er-mk-atom "badarg")))
-        (not (er-fun? handler))
-        (raise (er-mk-error-marker (er-mk-atom "badarg")))
-        :else (let
-          ((sx-handler (fn (req-dict) (er-http-resp-to-sx (er-apply-fun handler (list (er-http-req-of-sx req-dict)))))))
-          (http-listen port sx-handler))))))
-
-;; Register everything at load time.
-(define
-  er-register-builtin-bifs!
-  (fn
-    ()
+(define er-register-builtin-bifs!
+  (fn ()
+    ;; erlang module — type predicates (all pure)
     (er-register-pure-bif! "erlang" "is_integer" 1 er-bif-is-integer)
     (er-register-pure-bif! "erlang" "is_atom" 1 er-bif-is-atom)
     (er-register-pure-bif! "erlang" "is_list" 1 er-bif-is-list)
@@ -1606,61 +1479,27 @@
     (er-register-pure-bif! "erlang" "is_float" 1 er-bif-is-float)
     (er-register-pure-bif! "erlang" "is_boolean" 1 er-bif-is-boolean)
     (er-register-pure-bif! "erlang" "is_pid" 1 er-bif-is-pid)
-    (er-register-pure-bif!
-      "erlang"
-      "is_reference"
-      1
-      er-bif-is-reference)
+    (er-register-pure-bif! "erlang" "is_reference" 1 er-bif-is-reference)
     (er-register-pure-bif! "erlang" "is_binary" 1 er-bif-is-binary)
-    (er-register-pure-bif!
-      "erlang"
-      "is_function"
-      1
-      er-bif-is-function)
-    (er-register-pure-bif!
-      "erlang"
-      "is_function"
-      2
-      er-bif-is-function)
+    (er-register-pure-bif! "erlang" "is_function" 1 er-bif-is-function)
+    (er-register-pure-bif! "erlang" "is_function" 2 er-bif-is-function)
+    ;; erlang module — pure data ops
     (er-register-pure-bif! "erlang" "length" 1 er-bif-length)
     (er-register-pure-bif! "erlang" "hd" 1 er-bif-hd)
     (er-register-pure-bif! "erlang" "tl" 1 er-bif-tl)
     (er-register-pure-bif! "erlang" "element" 2 er-bif-element)
     (er-register-pure-bif! "erlang" "tuple_size" 1 er-bif-tuple-size)
     (er-register-pure-bif! "erlang" "byte_size" 1 er-bif-byte-size)
-    (er-register-pure-bif!
-      "erlang"
-      "atom_to_list"
-      1
-      er-bif-atom-to-list)
-    (er-register-pure-bif!
-      "erlang"
-      "list_to_atom"
-      1
-      er-bif-list-to-atom)
+    (er-register-pure-bif! "erlang" "atom_to_list" 1 er-bif-atom-to-list)
+    (er-register-pure-bif! "erlang" "list_to_atom" 1 er-bif-list-to-atom)
     (er-register-pure-bif! "erlang" "abs" 1 er-bif-abs)
     (er-register-pure-bif! "erlang" "min" 2 er-bif-min)
     (er-register-pure-bif! "erlang" "max" 2 er-bif-max)
-    (er-register-pure-bif!
-      "erlang"
-      "tuple_to_list"
-      1
-      er-bif-tuple-to-list)
-    (er-register-pure-bif!
-      "erlang"
-      "list_to_tuple"
-      1
-      er-bif-list-to-tuple)
-    (er-register-pure-bif!
-      "erlang"
-      "integer_to_list"
-      1
-      er-bif-integer-to-list)
-    (er-register-pure-bif!
-      "erlang"
-      "list_to_integer"
-      1
-      er-bif-list-to-integer)
+    (er-register-pure-bif! "erlang" "tuple_to_list" 1 er-bif-tuple-to-list)
+    (er-register-pure-bif! "erlang" "list_to_tuple" 1 er-bif-list-to-tuple)
+    (er-register-pure-bif! "erlang" "integer_to_list" 1 er-bif-integer-to-list)
+    (er-register-pure-bif! "erlang" "list_to_integer" 1 er-bif-list-to-integer)
+    ;; erlang module — process / runtime (side-effecting)
     (er-register-bif! "erlang" "self" 0 er-bif-self)
     (er-register-bif! "erlang" "spawn" 1 er-bif-spawn)
     (er-register-bif! "erlang" "spawn" 3 er-bif-spawn)
@@ -1676,16 +1515,12 @@
     (er-register-bif! "erlang" "unregister" 1 er-bif-unregister)
     (er-register-bif! "erlang" "whereis" 1 er-bif-whereis)
     (er-register-bif! "erlang" "registered" 0 er-bif-registered)
-    (er-register-bif!
-      "erlang"
-      "throw"
-      1
+    ;; erlang module — exception raising (modelled as side-effecting)
+    (er-register-bif! "erlang" "throw" 1
       (fn (vs) (raise (er-mk-throw-marker (er-bif-arg1 vs "throw")))))
-    (er-register-bif!
-      "erlang"
-      "error"
-      1
+    (er-register-bif! "erlang" "error" 1
       (fn (vs) (raise (er-mk-error-marker (er-bif-arg1 vs "error")))))
+    ;; lists module — all pure
     (er-register-pure-bif! "lists" "reverse" 1 er-bif-lists-reverse)
     (er-register-pure-bif! "lists" "map" 2 er-bif-lists-map)
     (er-register-pure-bif! "lists" "foldl" 3 er-bif-lists-foldl)
@@ -1699,13 +1534,11 @@
     (er-register-pure-bif! "lists" "filter" 2 er-bif-lists-filter)
     (er-register-pure-bif! "lists" "any" 2 er-bif-lists-any)
     (er-register-pure-bif! "lists" "all" 2 er-bif-lists-all)
-    (er-register-pure-bif!
-      "lists"
-      "duplicate"
-      2
-      er-bif-lists-duplicate)
+    (er-register-pure-bif! "lists" "duplicate" 2 er-bif-lists-duplicate)
+    ;; io module — side-effecting (writes to io buffer)
     (er-register-bif! "io" "format" 1 er-bif-io-format)
     (er-register-bif! "io" "format" 2 er-bif-io-format)
+    ;; ets module — side-effecting (mutates table state)
     (er-register-bif! "ets" "new" 2 er-bif-ets-new)
     (er-register-bif! "ets" "insert" 2 er-bif-ets-insert)
     (er-register-bif! "ets" "lookup" 2 er-bif-ets-lookup)
@@ -1713,88 +1546,82 @@
     (er-register-bif! "ets" "delete" 2 er-bif-ets-delete)
     (er-register-bif! "ets" "tab2list" 1 er-bif-ets-tab2list)
     (er-register-bif! "ets" "info" 2 er-bif-ets-info)
+    ;; code module — side-effecting (mutates module registry, kills procs)
     (er-register-bif! "code" "load_binary" 3 er-bif-code-load-binary)
     (er-register-bif! "code" "purge" 1 er-bif-code-purge)
     (er-register-bif! "code" "soft_purge" 1 er-bif-code-soft-purge)
     (er-register-bif! "code" "which" 1 er-bif-code-which)
     (er-register-bif! "code" "is_loaded" 1 er-bif-code-is-loaded)
     (er-register-bif! "code" "all_loaded" 0 er-bif-code-all-loaded)
+    ;; file module
     (er-register-bif! "file" "read_file" 1 er-bif-file-read-file)
     (er-register-bif! "file" "write_file" 2 er-bif-file-write-file)
     (er-register-bif! "file" "delete" 1 er-bif-file-delete)
+    ;; Phase 8 FFI — host-primitive BIFs (loops/fed-prims)
     (er-register-pure-bif! "crypto" "hash" 2 er-bif-crypto-hash)
     (er-register-pure-bif! "cid" "from_bytes" 1 er-bif-cid-from-bytes)
     (er-register-pure-bif! "cid" "to_string" 1 er-bif-cid-to-string)
-    (define
-      er-bif-binary-to-list
-      (fn
-        (vs)
-        (let
-          ((v (nth vs 0)))
-          (cond
-            (not (er-binary? v))
-            (raise (er-mk-error-marker (er-mk-atom "badarg")))
-            :else (let
-              ((bs (get v :bytes)) (out (er-mk-nil)))
-              (for-each
-                (fn
-                  (i)
-                  (set!
-                    out
-                    (er-mk-cons (nth bs (- (- (len bs) 1) i)) out)))
-                (range 0 (len bs)))
-              out)))))
-    (define
-      er-iolist-walk!
-      (fn
-        (v acc fail)
-        (cond
-          (nth fail 0)
-          nil
-          (er-nil? v)
-          nil
-          (er-cons? v)
-          (do
-            (er-iolist-walk! (get v :head) acc fail)
+
+;; ── binary_to_list / list_to_binary (Step 3b — term codec) ──────
+;; Standard Erlang semantics:
+;;   binary_to_list(<<B1,B2,...>>) -> [B1, B2, ...]   (Erlang cons of ints)
+;;   list_to_binary(IoList)        -> <<...>>         (flattens nested
+;;     iolists; elements are byte ints 0-255 or binaries)
+;; Bad arg / out-of-range byte / non-iolist element -> error:badarg.
+
+(define er-bif-binary-to-list
+  (fn (vs)
+    (let ((v (nth vs 0)))
+      (cond
+        (not (er-binary? v))
+          (raise (er-mk-error-marker (er-mk-atom "badarg")))
+        :else
+          (let ((bs (get v :bytes)) (out (er-mk-nil)))
+            (for-each
+              (fn (i)
+                (set! out (er-mk-cons (nth bs (- (- (len bs) 1) i)) out)))
+              (range 0 (len bs)))
+            out)))))
+
+;; Walk an Erlang iolist, appending bytes to `acc` (a mutable SX list).
+;; Accepts: nil, cons-of-X, binary, integer in 0..255. Anything else
+;; signals failure by setting (nth fail 0) to true.
+(define er-iolist-walk!
+  (fn (v acc fail)
+    (cond
+      (nth fail 0) nil
+      (er-nil? v) nil
+      (er-cons? v)
+        (do (er-iolist-walk! (get v :head) acc fail)
             (er-iolist-walk! (get v :tail) acc fail))
-          (er-binary? v)
-          (for-each
-            (fn (i) (append! acc (nth (get v :bytes) i)))
-            (range 0 (len (get v :bytes))))
-          (= (type-of v) "number")
-          (cond
-            (and (>= v 0) (<= v 255))
-            (append! acc v)
-            :else (set-nth! fail 0 true))
-          :else (set-nth! fail 0 true))))
-    (define
-      er-bif-list-to-binary
-      (fn
-        (vs)
-        (let
-          ((v (nth vs 0)) (acc (list)) (fail (list false)))
-          (cond
-            (not (or (er-nil? v) (er-cons? v) (er-binary? v)))
-            (raise (er-mk-error-marker (er-mk-atom "badarg")))
-            :else (do
-              (er-iolist-walk! v acc fail)
-              (cond
-                (nth fail 0)
+      (er-binary? v)
+        (for-each
+          (fn (i) (append! acc (nth (get v :bytes) i)))
+          (range 0 (len (get v :bytes))))
+      (= (type-of v) "number")
+        (cond
+          (and (>= v 0) (<= v 255)) (append! acc v)
+          :else (set-nth! fail 0 true))
+      :else (set-nth! fail 0 true))))
+
+(define er-bif-list-to-binary
+  (fn (vs)
+    (let ((v (nth vs 0)) (acc (list)) (fail (list false)))
+      (cond
+        (not (or (er-nil? v) (er-cons? v) (er-binary? v)))
+          (raise (er-mk-error-marker (er-mk-atom "badarg")))
+        :else
+          (do
+            (er-iolist-walk! v acc fail)
+            (cond
+              (nth fail 0)
                 (raise (er-mk-error-marker (er-mk-atom "badarg")))
-                :else (er-mk-binary acc)))))))
+              :else (er-mk-binary acc)))))))
+
     (er-register-bif! "file" "list_dir" 1 er-bif-file-list-dir)
-    (er-register-pure-bif!
-      "erlang"
-      "binary_to_list"
-      1
-      er-bif-binary-to-list)
-    (er-register-pure-bif!
-      "erlang"
-      "list_to_binary"
-      1
-      er-bif-list-to-binary)
+    (er-register-pure-bif! "erlang" "binary_to_list" 1 er-bif-binary-to-list)
+    (er-register-pure-bif! "erlang" "list_to_binary"  1 er-bif-list-to-binary)
     (er-mk-atom "ok")))
 
-(er-register-bif! "http" "listen" 2 er-bif-http-listen)
-
+;; Register everything at load time.
 (er-register-builtin-bifs!)

lib/go/conformance.sh

@@ -0,0 +1,141 @@
+#!/usr/bin/env bash
+# Go-on-SX conformance runner.
+#
+# Loads every Go-on-SX test suite via the epoch protocol, collects
+# pass/fail counts, and writes lib/go/scoreboard.json + .md.
+#
+# Usage:
+#   bash lib/go/conformance.sh           # run all suites
+#   bash lib/go/conformance.sh -v        # verbose per-suite
+
+set -uo pipefail
+cd "$(git rev-parse --show-toplevel)"
+
+SX_SERVER="${SX_SERVER:-hosts/ocaml/_build/default/bin/sx_server.exe}"
+if [ ! -x "$SX_SERVER" ]; then
+  SX_SERVER="/root/rose-ash/hosts/ocaml/_build/default/bin/sx_server.exe"
+fi
+if [ ! -x "$SX_SERVER" ]; then
+  echo "ERROR: sx_server.exe not found." >&2
+  exit 1
+fi
+
+VERBOSE="${1:-}"
+TMPFILE=$(mktemp)
+OUTFILE=$(mktemp)
+trap "rm -f $TMPFILE $OUTFILE" EXIT
+
+# Each suite: name | pass-counter | total-counter
+SUITES=(
+  "lex|go-test-pass|go-test-count"
+  "parse|go-parse-test-pass|go-parse-test-count"
+  "types|go-types-test-pass|go-types-test-count"
+  "eval|go-eval-test-pass|go-eval-test-count"
+  "runtime|go-rt-test-pass|go-rt-test-count"
+  "stdlib|go-std-test-pass|go-std-test-count"
+  "e2e|go-e2e-test-pass|go-e2e-test-count"
+)
+
+cat > "$TMPFILE" <<'EPOCHS'
+(epoch 1)
+(load "lib/guest/lex.sx")
+(load "lib/guest/ast.sx")
+(load "lib/guest/pratt.sx")
+(load "lib/go/lex.sx")
+(load "lib/go/parse.sx")
+(load "lib/go/types.sx")
+(load "lib/go/sched.sx")
+(load "lib/go/eval.sx")
+(load "lib/go/std/strings.sx")
+(load "lib/go/std/strconv.sx")
+(load "lib/go/tests/lex.sx")
+(load "lib/go/tests/parse.sx")
+(load "lib/go/tests/types.sx")
+(load "lib/go/tests/eval.sx")
+(load "lib/go/tests/runtime.sx")
+(load "lib/go/tests/stdlib.sx")
+(load "lib/go/tests/e2e.sx")
+EPOCHS
+
+idx=0
+for entry in "${SUITES[@]}"; do
+  name="${entry%%|*}"
+  pass_var=$(echo "$entry" | awk -F'|' '{print $2}')
+  total_var=$(echo "$entry" | awk -F'|' '{print $3}')
+  epoch=$((100 + idx))
+  echo "(epoch $epoch)" >> "$TMPFILE"
+  echo "(eval \"(list $pass_var $total_var)\")" >> "$TMPFILE"
+  idx=$((idx + 1))
+done
+
+"$SX_SERVER" < "$TMPFILE" > "$OUTFILE" 2>&1
+
+parse_pair() {
+  local epoch="$1"
+  local line
+  line=$(grep -A1 "^(ok-len $epoch " "$OUTFILE" | tail -1)
+  echo "$line" | sed -E 's/[()]//g'
+}
+
+TOTAL_PASS=0
+TOTAL_COUNT=0
+JSON_SUITES=""
+MD_ROWS=""
+
+idx=0
+for entry in "${SUITES[@]}"; do
+  name="${entry%%|*}"
+  epoch=$((100 + idx))
+  pair=$(parse_pair "$epoch")
+  pass=$(echo "$pair" | awk '{print $1}')
+  count=$(echo "$pair" | awk '{print $2}')
+  if [ -z "$pass" ] || [ -z "$count" ]; then
+    pass=0
+    count=0
+  fi
+  TOTAL_PASS=$((TOTAL_PASS + pass))
+  TOTAL_COUNT=$((TOTAL_COUNT + count))
+  status="ok"
+  marker="✅"
+  if [ "$pass" != "$count" ]; then
+    status="fail"
+    marker="❌"
+  fi
+  if [ "$VERBOSE" = "-v" ]; then
+    printf "  %-12s %s/%s\n" "$name" "$pass" "$count"
+  fi
+  if [ -n "$JSON_SUITES" ]; then JSON_SUITES+=","; fi
+  JSON_SUITES+=$'\n    '
+  JSON_SUITES+="{\"name\":\"$name\",\"pass\":$pass,\"total\":$count,\"status\":\"$status\"}"
+  MD_ROWS+="| $marker | $name | $pass | $count |"$'\n'
+  idx=$((idx + 1))
+done
+
+printf '\nGo-on-SX conformance: %d / %d\n' "$TOTAL_PASS" "$TOTAL_COUNT"
+
+cat > lib/go/scoreboard.json <<JSON
+{
+  "language": "go",
+  "total_pass": $TOTAL_PASS,
+  "total": $TOTAL_COUNT,
+  "suites": [$JSON_SUITES]
+}
+JSON
+
+cat > lib/go/scoreboard.md <<MD
+# Go-on-SX Scoreboard
+
+**Total: ${TOTAL_PASS} / ${TOTAL_COUNT} tests passing**
+
+|  | Suite | Pass | Total |
+|---|---|---|---|
+$MD_ROWS
+
+Generated by \`lib/go/conformance.sh\`.
+MD
+
+if [ "$TOTAL_PASS" -eq "$TOTAL_COUNT" ]; then
+  exit 0
+else
+  exit 1
+fi

lib/go/lex.sx

@@ -0,0 +1,476 @@
+;; lib/go/lex.sx — Go tokenizer with automatic semicolon insertion.
+;;
+;; Consumes lib/guest/lex.sx character-class predicates.
+;;
+;; Tokens: {:type T :value V :pos P}
+;; Types:
+;;   "ident"   — identifiers (foo, _bar, mixedCase)
+;;   "keyword" — one of the 25 Go keywords
+;;   "int"     — integer literals (decimal, 0x.. hex, 0b.. binary, 0o.. octal,
+;;               legacy 0123 octal; underscores between digits allowed)
+;;   "float"   — decimal float literals (3.14, .5, 1., 1e10, 1.5e-3, 1E5)
+;;   "imag"    — imaginary literals (2i, 3.14i, 1e2i)
+;;   "string"  — interpreted string literals "..." OR raw string literals `...`
+;;   "rune"    — rune literals 'x' (single char + simple escapes)
+;;   "op"      — operators & punctuation; :value is the literal text
+;;   "semi"    — explicit ';' or auto-inserted (Go spec § Semicolons)
+;;   "eof"     — end-of-input sentinel
+;;
+;; ASI (Go spec § Semicolons): a newline (or EOF, or a block comment
+;; containing a newline) emits a ";semi" if the previous emitted token's
+;; type is ident/int/float/imag/string/rune, or its value is one of
+;;   {break, continue, fallthrough, return, ++, --, ), ], }}.
+;;
+;; All scanner locals are gl- prefixed: SX host primitives (peek/emit/etc.)
+;; silently shadow guest-language defines. See feedback_sx_bind_clash.
+
+(define
+  go-keywords
+  (list
+    "break"
+    "case"
+    "chan"
+    "const"
+    "continue"
+    "default"
+    "defer"
+    "else"
+    "fallthrough"
+    "for"
+    "func"
+    "go"
+    "goto"
+    "if"
+    "import"
+    "interface"
+    "map"
+    "package"
+    "range"
+    "return"
+    "select"
+    "struct"
+    "switch"
+    "type"
+    "var"))
+
+(define go-keyword? (fn (s) (some (fn (k) (= k s)) go-keywords)))
+
+(define go-asi-keywords (list "break" "continue" "fallthrough" "return"))
+
+(define go-asi-ops (list "++" "--" ")" "]" "}"))
+
+(define go-asi-lit-types (list "ident" "int" "float" "imag" "string" "rune"))
+
+(define
+  go-asi-trigger?
+  (fn
+    (tok)
+    (if
+      (= tok nil)
+      false
+      (let
+        ((ty (get tok :type)) (v (get tok :value)))
+        (or
+          (some (fn (lt) (= lt ty)) go-asi-lit-types)
+          (and (= ty "keyword") (some (fn (k) (= k v)) go-asi-keywords))
+          (and (= ty "op") (some (fn (o) (= o v)) go-asi-ops)))))))
+
+(define
+  go-tokenize
+  (fn
+    (src)
+    (let
+      ((tokens (list)) (pos 0) (src-len (len src)))
+      (define
+        gl-peek
+        (fn
+          (offset)
+          (if (< (+ pos offset) src-len) (nth src (+ pos offset)) nil)))
+      (define gl-cur (fn () (gl-peek 0)))
+      (define gl-advance! (fn (n) (set! pos (+ pos n))))
+      (define
+        gl-last
+        (fn
+          ()
+          (if
+            (= (len tokens) 0)
+            nil
+            (nth tokens (- (len tokens) 1)))))
+      (define gl-emit! (fn (type value start) (append! tokens {:type type :value value :pos start})))
+      (define
+        gl-maybe-asi!
+        (fn
+          (at)
+          (when (go-asi-trigger? (gl-last)) (gl-emit! "semi" "\n" at))))
+      (define
+        gl-oct-digit?
+        (fn (c) (and (not (= c nil)) (>= c "0") (<= c "7"))))
+      (define gl-bin-digit? (fn (c) (or (= c "0") (= c "1"))))
+      (define
+        gl-skip-line!
+        (fn
+          ()
+          (when
+            (and (< pos src-len) (not (= (gl-cur) "\n")))
+            (gl-advance! 1)
+            (gl-skip-line!))))
+      (define
+        gl-skip-block!
+        (fn
+          (saw-nl)
+          (cond
+            (>= pos src-len)
+            saw-nl
+            (and (= (gl-cur) "*") (= (gl-peek 1) "/"))
+            (do (gl-advance! 2) saw-nl)
+            :else (let
+              ((is-nl (= (gl-cur) "\n")))
+              (gl-advance! 1)
+              (gl-skip-block! (or saw-nl is-nl))))))
+      (define
+        gl-read-ident!
+        (fn
+          (start)
+          (when
+            (and (< pos src-len) (lex-ident-char? (gl-cur)))
+            (gl-advance! 1)
+            (gl-read-ident! start))
+          (slice src start pos)))
+      (define
+        gl-read-digit-run!
+        (fn
+          (digit?)
+          (when
+            (and (< pos src-len) (or (digit? (gl-cur)) (= (gl-cur) "_")))
+            (gl-advance! 1)
+            (gl-read-digit-run! digit?))))
+      (define
+        gl-finish-number!
+        (fn
+          (has-fraction?)
+          (let
+            ((typ (if has-fraction? "float" "int")))
+            (when
+              (or (= (gl-cur) "e") (= (gl-cur) "E"))
+              (gl-advance! 1)
+              (when
+                (or (= (gl-cur) "+") (= (gl-cur) "-"))
+                (gl-advance! 1))
+              (gl-read-digit-run! lex-digit?)
+              (set! typ "float"))
+            (cond
+              (= (gl-cur) "i")
+              (do (gl-advance! 1) "imag")
+              :else typ))))
+      (define
+        gl-read-number!
+        (fn
+          ()
+          (cond
+            (and (= (gl-cur) ".") (lex-digit? (gl-peek 1)))
+            (do
+              (gl-advance! 1)
+              (gl-read-digit-run! lex-digit?)
+              (gl-finish-number! true))
+            (and
+              (= (gl-cur) "0")
+              (or
+                (= (gl-peek 1) "x")
+                (= (gl-peek 1) "X")))
+            (do
+              (gl-advance! 2)
+              (gl-read-digit-run! lex-hex-digit?)
+              "int")
+            (and
+              (= (gl-cur) "0")
+              (or
+                (= (gl-peek 1) "b")
+                (= (gl-peek 1) "B")))
+            (do
+              (gl-advance! 2)
+              (gl-read-digit-run! gl-bin-digit?)
+              "int")
+            (and
+              (= (gl-cur) "0")
+              (or
+                (= (gl-peek 1) "o")
+                (= (gl-peek 1) "O")))
+            (do
+              (gl-advance! 2)
+              (gl-read-digit-run! gl-oct-digit?)
+              "int")
+            :else (do
+              (gl-read-digit-run! lex-digit?)
+              (cond
+                (and (= (gl-cur) ".") (not (= (gl-peek 1) ".")))
+                (do
+                  (gl-advance! 1)
+                  (gl-read-digit-run! lex-digit?)
+                  (gl-finish-number! true))
+                :else (gl-finish-number! false))))))
+      (define
+        gl-read-string!
+        (fn
+          ()
+          (gl-advance! 1)
+          (let
+            ((chars (list)))
+            (define
+              gl-string-loop
+              (fn
+                ()
+                (cond
+                  (>= pos src-len)
+                  nil
+                  (= (gl-cur) "\"")
+                  (gl-advance! 1)
+                  (= (gl-cur) "\\")
+                  (do
+                    (gl-advance! 1)
+                    (when
+                      (< pos src-len)
+                      (let
+                        ((ch (gl-cur)))
+                        (cond
+                          (= ch "n")
+                          (append! chars "\n")
+                          (= ch "t")
+                          (append! chars "\t")
+                          (= ch "r")
+                          (append! chars "\r")
+                          (= ch "\\")
+                          (append! chars "\\")
+                          (= ch "\"")
+                          (append! chars "\"")
+                          (= ch "'")
+                          (append! chars "'")
+                          :else (append! chars ch))
+                        (gl-advance! 1)))
+                    (gl-string-loop))
+                  :else (do
+                    (append! chars (gl-cur))
+                    (gl-advance! 1)
+                    (gl-string-loop)))))
+            (gl-string-loop)
+            (join "" chars))))
+      (define
+        gl-read-raw-string!
+        (fn
+          ()
+          (gl-advance! 1)
+          (let
+            ((chars (list)))
+            (define
+              gl-raw-loop
+              (fn
+                ()
+                (cond
+                  (>= pos src-len)
+                  nil
+                  (= (gl-cur) "`")
+                  (gl-advance! 1)
+                  (= (gl-cur) "\r")
+                  (do (gl-advance! 1) (gl-raw-loop))
+                  :else (do
+                    (append! chars (gl-cur))
+                    (gl-advance! 1)
+                    (gl-raw-loop)))))
+            (gl-raw-loop)
+            (join "" chars))))
+      (define
+        gl-read-rune!
+        (fn
+          ()
+          (gl-advance! 1)
+          (let
+            ((chars (list)))
+            (cond
+              (and (< pos src-len) (= (gl-cur) "\\"))
+              (do
+                (gl-advance! 1)
+                (when
+                  (< pos src-len)
+                  (let
+                    ((ch (gl-cur)))
+                    (cond
+                      (= ch "n")
+                      (append! chars "\n")
+                      (= ch "t")
+                      (append! chars "\t")
+                      (= ch "r")
+                      (append! chars "\r")
+                      (= ch "\\")
+                      (append! chars "\\")
+                      (= ch "'")
+                      (append! chars "'")
+                      (= ch "\"")
+                      (append! chars "\"")
+                      :else (append! chars ch))
+                    (gl-advance! 1))))
+              (< pos src-len)
+              (do (append! chars (gl-cur)) (gl-advance! 1)))
+            (when
+              (and (< pos src-len) (= (gl-cur) "'"))
+              (gl-advance! 1))
+            (join "" chars))))
+      (define
+        gl-match-op
+        (fn
+          ()
+          (let
+            ((c0 (gl-cur))
+              (c1 (gl-peek 1))
+              (c2 (gl-peek 2)))
+            (cond
+              (and (= c0 "<") (= c1 "<") (= c2 "="))
+              "<<="
+              (and (= c0 ">") (= c1 ">") (= c2 "="))
+              ">>="
+              (and (= c0 "&") (= c1 "^") (= c2 "="))
+              "&^="
+              (and (= c0 ".") (= c1 ".") (= c2 "."))
+              "..."
+              (and (= c0 "=") (= c1 "="))
+              "=="
+              (and (= c0 "!") (= c1 "="))
+              "!="
+              (and (= c0 "<") (= c1 "="))
+              "<="
+              (and (= c0 ">") (= c1 "="))
+              ">="
+              (and (= c0 "&") (= c1 "&"))
+              "&&"
+              (and (= c0 "|") (= c1 "|"))
+              "||"
+              (and (= c0 "+") (= c1 "+"))
+              "++"
+              (and (= c0 "-") (= c1 "-"))
+              "--"
+              (and (= c0 "<") (= c1 "<"))
+              "<<"
+              (and (= c0 ">") (= c1 ">"))
+              ">>"
+              (and (= c0 "+") (= c1 "="))
+              "+="
+              (and (= c0 "-") (= c1 "="))
+              "-="
+              (and (= c0 "*") (= c1 "="))
+              "*="
+              (and (= c0 "/") (= c1 "="))
+              "/="
+              (and (= c0 "%") (= c1 "="))
+              "%="
+              (and (= c0 "&") (= c1 "="))
+              "&="
+              (and (= c0 "|") (= c1 "="))
+              "|="
+              (and (= c0 "^") (= c1 "="))
+              "^="
+              (and (= c0 ":") (= c1 "="))
+              ":="
+              (and (= c0 "<") (= c1 "-"))
+              "<-"
+              (and (= c0 "&") (= c1 "^"))
+              "&^"
+              (or
+                (= c0 "+")
+                (= c0 "-")
+                (= c0 "*")
+                (= c0 "/")
+                (= c0 "%")
+                (= c0 "&")
+                (= c0 "|")
+                (= c0 "^")
+                (= c0 "<")
+                (= c0 ">")
+                (= c0 "=")
+                (= c0 "!")
+                (= c0 "(")
+                (= c0 ")")
+                (= c0 "{")
+                (= c0 "}")
+                (= c0 "[")
+                (= c0 "]")
+                (= c0 ",")
+                (= c0 ".")
+                (= c0 ":")
+                (= c0 "~"))
+              c0
+              :else nil))))
+      (define
+        gl-scan!
+        (fn
+          ()
+          (cond
+            (>= pos src-len)
+            nil
+            (= (gl-cur) "\n")
+            (do (gl-maybe-asi! pos) (gl-advance! 1) (gl-scan!))
+            (lex-space? (gl-cur))
+            (do (gl-advance! 1) (gl-scan!))
+            (and (= (gl-cur) "/") (= (gl-peek 1) "/"))
+            (do (gl-advance! 2) (gl-skip-line!) (gl-scan!))
+            (and (= (gl-cur) "/") (= (gl-peek 1) "*"))
+            (do
+              (gl-advance! 2)
+              (let
+                ((saw-nl (gl-skip-block! false)))
+                (when saw-nl (gl-maybe-asi! pos)))
+              (gl-scan!))
+            (= (gl-cur) ";")
+            (do
+              (gl-emit! "semi" ";" pos)
+              (gl-advance! 1)
+              (gl-scan!))
+            (lex-ident-start? (gl-cur))
+            (do
+              (let
+                ((start pos))
+                (gl-read-ident! start)
+                (let
+                  ((word (slice src start pos)))
+                  (gl-emit!
+                    (if (go-keyword? word) "keyword" "ident")
+                    word
+                    start)))
+              (gl-scan!))
+            (lex-digit? (gl-cur))
+            (do
+              (let
+                ((start pos) (typ (gl-read-number!)))
+                (gl-emit! typ (slice src start pos) start))
+              (gl-scan!))
+            (and (= (gl-cur) ".") (lex-digit? (gl-peek 1)))
+            (do
+              (let
+                ((start pos) (typ (gl-read-number!)))
+                (gl-emit! typ (slice src start pos) start))
+              (gl-scan!))
+            (= (gl-cur) "\"")
+            (let
+              ((start pos) (v (gl-read-string!)))
+              (gl-emit! "string" v start)
+              (gl-scan!))
+            (= (gl-cur) "`")
+            (let
+              ((start pos) (v (gl-read-raw-string!)))
+              (gl-emit! "string" v start)
+              (gl-scan!))
+            (= (gl-cur) "'")
+            (let
+              ((start pos) (v (gl-read-rune!)))
+              (gl-emit! "rune" v start)
+              (gl-scan!))
+            :else (let
+              ((op (gl-match-op)))
+              (cond
+                op
+                (do
+                  (gl-emit! "op" op pos)
+                  (gl-advance! (len op))
+                  (gl-scan!))
+                :else (do (gl-advance! 1) (gl-scan!)))))))
+      (gl-scan!)
+      (gl-maybe-asi! pos)
+      (gl-emit! "eof" nil pos)
+      tokens)))

lib/go/sched.sx

@@ -0,0 +1,66 @@
+;; lib/go/sched.sx — Go scheduler primitives: channels + goroutines.
+;;
+;; This is **the independent implementation** referenced by
+;; plans/lib-guest-scheduler.md. The shape that emerges here informs
+;; the eventual sister kit; this file's structures are the Phase 5
+;; "first-consumer" cut.
+;;
+;; v0 concurrency model — IMPORTANT
+;;
+;; SX has no first-class continuations exposed to guest code, so we
+;; can't suspend a goroutine mid-statement. v0 runs `go f()` SYNCHRO-
+;; NOUSLY (it's an immediate call whose return value is dropped). This
+;; preserves the right semantics for patterns where the spawned
+;; goroutine simply pushes to a channel that the main goroutine then
+;; receives — because the spawned goroutine runs to completion first
+;; and leaves the value in the channel buffer.
+;;
+;; True preemption with blocking sends/recvs is a Phase 5b refinement.
+;; The sister-plan diary tracks the design insight (single
+;; sched-spawn primitive, channel-op direction tag) so the eventual
+;; kit doesn't bake in v0's synchronous limitation.
+;;
+;; Channel representation
+;;
+;;   (list :go-chan ACCESSORS-FN-LIST)
+;;
+;; ACCESSORS-FN-LIST is a list of closures sharing a mutable buffer
+;; and a closed flag. The closures expose:
+;;   index 1: send-fn     — (lambda (val) ...)
+;;   index 2: recv-fn     — (lambda () val-or-:empty)
+;;   index 3: closed?-fn  — (lambda () bool)
+;;   index 4: close!-fn   — (lambda () ...)
+;;
+;; Channel identity: distinct calls to go-make-chan produce closures
+;; with distinct identity — `(= ch1 ch2)` is false for distinct
+;; channels, matching Go spec § Channel types.
+
+(define
+  go-make-chan
+  (fn
+    ()
+    (let
+      ((buf (list)) (closed false))
+      (list
+        :go-chan (fn (v) (append! buf v) nil)
+        (fn
+          ()
+          (cond
+            (= (len buf) 0)
+            :empty :else
+            (let ((v (first buf))) (set! buf (rest buf)) v)))
+        (fn () closed)
+        (fn () (set! closed true) nil)
+        (fn () (len buf))))))
+
+(define
+  go-chan?
+  (fn
+    (v)
+    (and (list? v) (not (= (len v) 0)) (= (first v) :go-chan))))
+
+(define go-chan-send! (fn (ch val) ((nth ch 1) val)))
+(define go-chan-recv! (fn (ch) ((nth ch 2))))
+(define go-chan-closed? (fn (ch) ((nth ch 3))))
+(define go-chan-close! (fn (ch) ((nth ch 4))))
+(define go-chan-len    (fn (ch) ((nth ch 5))))

lib/go/scoreboard.json

@@ -0,0 +1,13 @@
+{
+  "language": "go",
+  "total_pass": 609,
+  "total": 609,
+  "suites": [
+    {"name":"lex","pass":129,"total":129,"status":"ok"},
+    {"name":"parse","pass":179,"total":179,"status":"ok"},
+    {"name":"types","pass":102,"total":102,"status":"ok"},
+    {"name":"eval","pass":106,"total":106,"status":"ok"},
+    {"name":"runtime","pass":40,"total":40,"status":"ok"},
+    {"name":"stdlib","pass":41,"total":41,"status":"ok"},
+    {"name":"e2e","pass":12,"total":12,"status":"ok"}]
+}

lib/go/scoreboard.md

@@ -0,0 +1,16 @@
+# Go-on-SX Scoreboard
+
+**Total: 609 / 609 tests passing**
+
+|  | Suite | Pass | Total |
+|---|---|---|---|
+| ✅ | lex | 129 | 129 |
+| ✅ | parse | 179 | 179 |
+| ✅ | types | 102 | 102 |
+| ✅ | eval | 106 | 106 |
+| ✅ | runtime | 40 | 40 |
+| ✅ | stdlib | 41 | 41 |
+| ✅ | e2e | 12 | 12 |
+
+
+Generated by `lib/go/conformance.sh`.

lib/go/std/strconv.sx

@@ -0,0 +1,71 @@
+;; lib/go/std/strconv.sx — Go's `strconv` package, v0 subset.
+
+(define
+  go-strconv-itoa
+  ;; Itoa(n) → string. Real Go returns the decimal representation.
+  (fn (args)
+    (cond
+      (not (= (len args) 1))
+      (list :eval-error :strconv-itoa-arity (len args))
+      :else
+      (let ((n (first args)))
+        (cond
+          (not (number? n)) (list :eval-error :strconv-itoa-not-number n)
+          :else (str n))))))
+
+(define
+  go-strconv-atoi
+  ;; Atoi(s) → (int, error). v0 returns just the int on success or
+  ;; an :eval-error on failure (multi-return is a later refinement).
+  (fn (args)
+    (cond
+      (not (= (len args) 1))
+      (list :eval-error :strconv-atoi-arity (len args))
+      :else
+      (let ((s (first args)))
+        (cond
+          (not (string? s)) (list :eval-error :strconv-atoi-not-string s)
+          (= (len s) 0) (list :eval-error :strconv-atoi-empty)
+          :else (go-strconv-parse-int s 0 (= (nth s 0) "-") 0))))))
+
+(define
+  go-strconv-parse-int
+  ;; Parse a (possibly signed) base-10 integer literal. Stops on the
+  ;; first non-digit char and returns the parsed prefix, or :eval-error
+  ;; if no digits were consumed.
+  (fn (s start neg acc)
+    (let ((i (cond (= start 0) (cond neg 1 :else 0) :else start)))
+      (cond
+        (>= i (len s))
+        (cond
+          (= (cond neg (- i 1) :else i) 0)
+          (list :eval-error :strconv-atoi-no-digits s)
+          :else
+          (cond neg (- 0 acc) :else acc))
+        :else
+        (let ((d (go-strconv-digit (nth s i))))
+          (cond
+            (< d 0)
+            (cond
+              (= (cond neg (- i 1) :else i) 0)
+              (list :eval-error :strconv-atoi-no-digits s)
+              :else
+              (cond neg (- 0 acc) :else acc))
+            :else
+            (go-strconv-parse-int s (+ i 1) neg (+ (* acc 10) d))))))))
+
+(define
+  go-strconv-digit
+  (fn (c)
+    (cond
+      (= c "0") 0  (= c "1") 1  (= c "2") 2  (= c "3") 3
+      (= c "4") 4  (= c "5") 5  (= c "6") 6  (= c "7") 7
+      (= c "8") 8  (= c "9") 9
+      :else -1)))
+
+(define
+  go-std-strconv
+  (list :go-package "strconv"
+    (list
+      (list "Itoa" (list :go-builtin-fn go-strconv-itoa))
+      (list "Atoi" (list :go-builtin-fn go-strconv-atoi)))))

lib/go/std/strings.sx

@@ -0,0 +1,386 @@
+;; lib/go/std/strings.sx — Go's `strings` package, v0 subset.
+;;
+;; Exposed as `go-std-strings`, a (:go-package "strings" ENTRIES) value.
+;; Register with `(go-env-extend env "strings" go-std-strings)` to make
+;; `strings.X(...)` call sites work in evaluated Go code.
+;;
+;; Each entry is (FIELD-NAME (list :go-fn PARAMS BODY)) — the same
+;; shape user-defined Go functions get. Bodies are written in SX
+;; directly via go-builtin closures wrapping host-level string ops
+;; for speed, OR as parsed Go source for fidelity. v0 uses
+;; go-builtin wrappers — simpler and fast.
+
+;; ── helpers: implement go-std-strings entries as builtins ────────
+
+(define
+  go-strings-contains
+  (fn (args)
+    (cond
+      (not (= (len args) 2))
+      (list :eval-error :strings-contains-arity (len args))
+      :else
+      (let ((s (first args)) (sub (nth args 1)))
+        (cond
+          (not (string? s)) (list :eval-error :strings-not-string s)
+          (not (string? sub)) (list :eval-error :strings-not-string sub)
+          :else
+          (go-strings-index-of s sub 0))))))
+
+(define
+  go-strings-index-of
+  ;; Returns true if SUB appears in S at or after START, else false.
+  (fn (s sub start)
+    (let ((slen (len s)) (sublen (len sub)))
+      (cond
+        (= sublen 0) true
+        (> (+ start sublen) slen) false
+        (go-strings-match-at s sub start 0) true
+        :else (go-strings-index-of s sub (+ start 1))))))
+
+(define
+  go-strings-match-at
+  (fn (s sub start k)
+    (cond
+      (>= k (len sub)) true
+      (= (nth s (+ start k)) (nth sub k))
+      (go-strings-match-at s sub start (+ k 1))
+      :else false)))
+
+(define
+  go-strings-has-prefix
+  (fn (args)
+    (cond
+      (not (= (len args) 2))
+      (list :eval-error :strings-hasprefix-arity (len args))
+      :else
+      (let ((s (first args)) (p (nth args 1)))
+        (cond
+          (not (string? s)) (list :eval-error :strings-not-string s)
+          (not (string? p)) (list :eval-error :strings-not-string p)
+          (> (len p) (len s)) false
+          :else (go-strings-match-at s p 0 0))))))
+
+(define
+  go-strings-has-suffix
+  (fn (args)
+    (cond
+      (not (= (len args) 2))
+      (list :eval-error :strings-hassuffix-arity (len args))
+      :else
+      (let ((s (first args)) (suf (nth args 1)))
+        (cond
+          (not (string? s)) (list :eval-error :strings-not-string s)
+          (not (string? suf)) (list :eval-error :strings-not-string suf)
+          (> (len suf) (len s)) false
+          :else
+          (go-strings-match-at s suf (- (len s) (len suf)) 0))))))
+
+(define
+  go-strings-index
+  (fn (args)
+    (cond
+      (not (= (len args) 2))
+      (list :eval-error :strings-index-arity (len args))
+      :else
+      (let ((s (first args)) (sub (nth args 1)))
+        (cond
+          (not (string? s)) (list :eval-error :strings-not-string s)
+          (not (string? sub)) (list :eval-error :strings-not-string sub)
+          :else (go-strings-index-loop s sub 0))))))
+
+(define
+  go-strings-index-loop
+  (fn (s sub start)
+    (let ((slen (len s)) (sublen (len sub)))
+      (cond
+        (= sublen 0) 0
+        (> (+ start sublen) slen) -1
+        (go-strings-match-at s sub start 0) start
+        :else (go-strings-index-loop s sub (+ start 1))))))
+
+(define
+  go-strings-repeat
+  (fn (args)
+    (cond
+      (not (= (len args) 2))
+      (list :eval-error :strings-repeat-arity (len args))
+      :else
+      (let ((s (first args)) (n (nth args 1)))
+        (cond
+          (not (string? s)) (list :eval-error :strings-not-string s)
+          (< n 0) (list :eval-error :strings-repeat-negative n)
+          :else (go-strings-repeat-loop s n ""))))))
+
+(define
+  go-strings-repeat-loop
+  (fn (s n acc)
+    (cond
+      (<= n 0) acc
+      :else (go-strings-repeat-loop s (- n 1) (str acc s)))))
+
+(define
+  go-strings-count
+  (fn (args)
+    (cond
+      (not (= (len args) 2))
+      (list :eval-error :strings-count-arity (len args))
+      :else
+      (let ((s (first args)) (sub (nth args 1)))
+        (cond
+          (not (string? s)) (list :eval-error :strings-not-string s)
+          (not (string? sub)) (list :eval-error :strings-not-string sub)
+          :else (go-strings-count-loop s sub 0 0))))))
+
+(define
+  go-strings-count-loop
+  (fn (s sub start acc)
+    (let ((idx (go-strings-index-loop s sub start)))
+      (cond
+        (< idx 0) acc
+        :else
+        (go-strings-count-loop s sub (+ idx (max 1 (len sub))) (+ acc 1))))))
+
+(define
+  go-strings-join
+  (fn (args)
+    (cond
+      (not (= (len args) 2))
+      (list :eval-error :strings-join-arity (len args))
+      :else
+      (let ((sep (nth args 1)) (xs (first args)))
+        (cond
+          (not (string? sep)) (list :eval-error :strings-not-string sep)
+          (not (and (list? xs) (= (first xs) :go-slice)))
+          (list :eval-error :strings-join-not-slice xs)
+          :else (go-strings-join-loop (nth xs 1) sep ""))))))
+
+(define
+  go-strings-join-loop
+  (fn (xs sep acc)
+    (cond
+      (= (len xs) 0) acc
+      (= (len acc) 0) (go-strings-join-loop (rest xs) sep (first xs))
+      :else
+      (go-strings-join-loop (rest xs) sep (str acc sep (first xs))))))
+
+;; ── case conversion ──────────────────────────────────────────────
+
+(define
+  go-strings-char-to-upper
+  (fn (c)
+    (cond
+      (and (>= c "a") (<= c "z"))
+      ;; ASCII uppercase shift: 'a' is 0x61, 'A' is 0x41 → diff 0x20.
+      ;; SX has no charcode primitive, so use a char-pair table.
+      (go-strings-letter-toggle c true)
+      :else c)))
+
+(define
+  go-strings-char-to-lower
+  (fn (c)
+    (cond
+      (and (>= c "A") (<= c "Z"))
+      (go-strings-letter-toggle c false)
+      :else c)))
+
+(define
+  go-strings-letter-toggle
+  ;; Toggle a single ASCII letter's case via direct mapping.
+  ;; `to-upper?` true means input is lowercase, output uppercase.
+  (fn (c to-upper?)
+    (cond
+      to-upper?
+      (cond
+        (= c "a") "A" (= c "b") "B" (= c "c") "C" (= c "d") "D"
+        (= c "e") "E" (= c "f") "F" (= c "g") "G" (= c "h") "H"
+        (= c "i") "I" (= c "j") "J" (= c "k") "K" (= c "l") "L"
+        (= c "m") "M" (= c "n") "N" (= c "o") "O" (= c "p") "P"
+        (= c "q") "Q" (= c "r") "R" (= c "s") "S" (= c "t") "T"
+        (= c "u") "U" (= c "v") "V" (= c "w") "W" (= c "x") "X"
+        (= c "y") "Y" (= c "z") "Z" :else c)
+      :else
+      (cond
+        (= c "A") "a" (= c "B") "b" (= c "C") "c" (= c "D") "d"
+        (= c "E") "e" (= c "F") "f" (= c "G") "g" (= c "H") "h"
+        (= c "I") "i" (= c "J") "j" (= c "K") "k" (= c "L") "l"
+        (= c "M") "m" (= c "N") "n" (= c "O") "o" (= c "P") "p"
+        (= c "Q") "q" (= c "R") "r" (= c "S") "s" (= c "T") "t"
+        (= c "U") "u" (= c "V") "v" (= c "W") "w" (= c "X") "x"
+        (= c "Y") "y" (= c "Z") "z" :else c))))
+
+(define
+  go-strings-map-chars
+  (fn (s i acc char-fn)
+    (cond
+      (>= i (len s)) acc
+      :else
+      (go-strings-map-chars s (+ i 1) (str acc (char-fn (nth s i))) char-fn))))
+
+(define
+  go-strings-to-upper
+  (fn (args)
+    (cond
+      (not (= (len args) 1))
+      (list :eval-error :strings-toupper-arity (len args))
+      :else
+      (let ((s (first args)))
+        (cond
+          (not (string? s)) (list :eval-error :strings-not-string s)
+          :else (go-strings-map-chars s 0 "" go-strings-char-to-upper))))))
+
+(define
+  go-strings-to-lower
+  (fn (args)
+    (cond
+      (not (= (len args) 1))
+      (list :eval-error :strings-tolower-arity (len args))
+      :else
+      (let ((s (first args)))
+        (cond
+          (not (string? s)) (list :eval-error :strings-not-string s)
+          :else (go-strings-map-chars s 0 "" go-strings-char-to-lower))))))
+
+;; ── TrimSpace ────────────────────────────────────────────────────
+
+(define
+  go-strings-is-space?
+  (fn (c)
+    (or (= c " ") (= c "\t") (= c "\n") (= c "\r"))))
+
+(define
+  go-strings-trim-left
+  (fn (s i)
+    (cond
+      (>= i (len s)) i
+      (go-strings-is-space? (nth s i)) (go-strings-trim-left s (+ i 1))
+      :else i)))
+
+(define
+  go-strings-trim-right
+  (fn (s end)
+    (cond
+      (<= end 0) 0
+      (go-strings-is-space? (nth s (- end 1))) (go-strings-trim-right s (- end 1))
+      :else end)))
+
+(define
+  go-strings-substr
+  ;; Substring [lo, hi) — naive but predictable.
+  (fn (s lo hi)
+    (cond
+      (>= lo hi) ""
+      :else
+      (go-strings-substr-loop s lo hi ""))))
+
+(define
+  go-strings-substr-loop
+  (fn (s i hi acc)
+    (cond
+      (>= i hi) acc
+      :else (go-strings-substr-loop s (+ i 1) hi (str acc (nth s i))))))
+
+(define
+  go-strings-trim-space
+  (fn (args)
+    (cond
+      (not (= (len args) 1))
+      (list :eval-error :strings-trimspace-arity (len args))
+      :else
+      (let ((s (first args)))
+        (cond
+          (not (string? s)) (list :eval-error :strings-not-string s)
+          :else
+          (let ((lo (go-strings-trim-left s 0)))
+            (let ((hi (go-strings-trim-right s (len s))))
+              (go-strings-substr s lo hi))))))))
+
+;; ── Split ────────────────────────────────────────────────────────
+
+(define
+  go-strings-split
+  (fn (args)
+    (cond
+      (not (= (len args) 2))
+      (list :eval-error :strings-split-arity (len args))
+      :else
+      (let ((s (first args)) (sep (nth args 1)))
+        (cond
+          (not (string? s)) (list :eval-error :strings-not-string s)
+          (not (string? sep)) (list :eval-error :strings-not-string sep)
+          (= (len sep) 0)
+          ;; Empty separator: real Go splits to all chars; v0 keeps
+          ;; behaviour simple — single-element slice.
+          (list :go-slice (list s))
+          :else
+          (list :go-slice (go-strings-split-loop s sep 0 (list))))))))
+
+(define
+  go-strings-split-loop
+  (fn (s sep start acc)
+    (let ((idx (go-strings-index-loop s sep start)))
+      (cond
+        (< idx 0)
+        (go-strings-split-finalize acc (go-strings-substr s start (len s)))
+        :else
+        (go-strings-split-loop s sep (+ idx (len sep))
+          (go-strings-split-finalize acc
+            (go-strings-substr s start idx)))))))
+
+(define
+  go-strings-split-finalize
+  ;; Append a piece to acc, growing the list in order.
+  (fn (acc piece)
+    (cond
+      (= (len acc) 0) (list piece)
+      :else (go-name-concat acc (list piece)))))
+
+;; ── Replace ──────────────────────────────────────────────────────
+
+(define
+  go-strings-replace
+  ;; Replace(s, old, new, n). n < 0 = all.
+  (fn (args)
+    (cond
+      (not (= (len args) 4))
+      (list :eval-error :strings-replace-arity (len args))
+      :else
+      (let ((s (first args)) (old (nth args 1))
+            (newv (nth args 2)) (n (nth args 3)))
+        (cond
+          (not (string? s)) (list :eval-error :strings-not-string s)
+          (not (string? old)) (list :eval-error :strings-not-string old)
+          (not (string? newv)) (list :eval-error :strings-not-string newv)
+          (= (len old) 0) s
+          :else (go-strings-replace-loop s old newv n 0 ""))))))
+
+(define
+  go-strings-replace-loop
+  (fn (s old newv n start acc)
+    (let ((idx (go-strings-index-loop s old start)))
+      (cond
+        (or (< idx 0) (= n 0))
+        (str acc (go-strings-substr s start (len s)))
+        :else
+        (go-strings-replace-loop s old newv
+          (cond (< n 0) -1 :else (- n 1))
+          (+ idx (len old))
+          (str acc (go-strings-substr s start idx) newv))))))
+
+;; ── go-std-strings package value ─────────────────────────────────
+
+(define
+  go-std-strings
+  (list :go-package "strings"
+    (list
+      (list "Contains"  (list :go-builtin-fn go-strings-contains))
+      (list "HasPrefix" (list :go-builtin-fn go-strings-has-prefix))
+      (list "HasSuffix" (list :go-builtin-fn go-strings-has-suffix))
+      (list "Index"     (list :go-builtin-fn go-strings-index))
+      (list "Count"     (list :go-builtin-fn go-strings-count))
+      (list "Repeat"    (list :go-builtin-fn go-strings-repeat))
+      (list "Join"      (list :go-builtin-fn go-strings-join))
+      (list "ToUpper"   (list :go-builtin-fn go-strings-to-upper))
+      (list "ToLower"   (list :go-builtin-fn go-strings-to-lower))
+      (list "TrimSpace" (list :go-builtin-fn go-strings-trim-space))
+      (list "Split"     (list :go-builtin-fn go-strings-split))
+      (list "Replace"   (list :go-builtin-fn go-strings-replace)))))

lib/go/tests/e2e.sx

@@ -0,0 +1,186 @@
+;; Go end-to-end tests — complete programs exercising lex+parse+
+;; types+eval+sched+stdlib together. Each test runs a multi-line Go
+;; program and inspects the final env.
+
+(define go-e2e-test-count 0)
+(define go-e2e-test-pass 0)
+(define go-e2e-test-fails (list))
+
+(define
+  go-e2e-test
+  (fn (name actual expected)
+    (set! go-e2e-test-count (+ go-e2e-test-count 1))
+    (if (= actual expected)
+      (set! go-e2e-test-pass (+ go-e2e-test-pass 1))
+      (append! go-e2e-test-fails
+        {:name name :expected expected :actual actual}))))
+
+(define
+  go-e2e-env
+  (go-env-extend
+    (go-env-extend go-env-builtins "strings" go-std-strings)
+    "strconv" go-std-strconv))
+
+(define
+  go-e2e-run
+  (fn (src-list)
+    (go-eval-program go-e2e-env (map go-parse src-list))))
+
+;; ── 1. Sieve via boolean slice (no modulo needed) ────────────────
+(go-e2e-test "e2e: sieve-of-Eratosthenes via boolean slice — count primes ≤ 30"
+  (let ((env (go-e2e-run
+              (list
+                ;; sieve[i] true means i is COMPOSITE (saves the
+                ;; default-bool initialisation for primes).
+                "sieve := []bool{false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false}"
+                "for p := 2; p < 31; p = p + 1 { if sieve[p] == false { for k := p + p; k < 31; k = k + p { sieve[k] = true } } }"
+                "count := 0"
+                "for i := 2; i < 31; i = i + 1 { if sieve[i] == false { count = count + 1 } }"))))
+    (go-env-lookup env "count"))
+  ;; primes ≤ 30: 2,3,5,7,11,13,17,19,23,29 = 10
+  10)
+
+;; ── 1b. Range-membership check (works without mod) ───────────────
+(go-e2e-test "e2e: linear search across slice of strings"
+  (let ((env (go-e2e-run
+              (list
+                "words := []string{\"apple\", \"banana\", \"cherry\", \"date\"}"
+                "func indexOf(xs []string, target string) int { for i, v := range xs { if v == target { return i } } ; return -1 }"
+                "i := indexOf(words, \"cherry\")"
+                "missing := indexOf(words, \"xyz\")"))))
+    (list (go-env-lookup env "i") (go-env-lookup env "missing")))
+  (list 2 -1))
+
+;; ── 2. Reverse a slice ───────────────────────────────────────────
+(go-e2e-test "e2e: reverse a slice of ints"
+  (let ((env (go-e2e-run
+              (list
+                "func reverse(xs []int) []int { r := []int{} ; for i := len(xs) - 1; i >= 0; i = i - 1 { r = append(r, xs[i]) } ; return r }"
+                "out := reverse([]int{1, 2, 3, 4, 5})"))))
+    (go-env-lookup env "out"))
+  (list :go-slice (list 5 4 3 2 1)))
+
+;; ── 3. Fibonacci (recursive) ─────────────────────────────────────
+(go-e2e-test "e2e: fib(10) = 55"
+  (let ((env (go-e2e-run
+              (list
+                "func fib(n int) int { if n < 2 { return n } ; return fib(n-1) + fib(n-2) }"
+                "r := fib(10)"))))
+    (go-env-lookup env "r"))
+  55)
+
+;; ── 4. Sum-of-squares via Map+Reduce ─────────────────────────────
+(go-e2e-test "e2e: sum-of-squares 1..5 via Map+Reduce"
+  (let ((env (go-e2e-run
+              (list
+                "func Map[T any, U any](xs []T, f func(T) U) []U { r := []int{} ; for i, v := range xs { r = append(r, f(v)) } ; return r }"
+                "func Reduce[T any, U any](xs []T, seed U, f func(U, T) U) U { acc := seed ; for i, v := range xs { acc = f(acc, v) } ; return acc }"
+                "func sq(x int) int { return x * x }"
+                "func add(a int, b int) int { return a + b }"
+                "squares := Map([]int{1, 2, 3, 4, 5}, sq)"
+                "total := Reduce(squares, 0, add)"))))
+    (go-env-lookup env "total"))
+  ;; 1 + 4 + 9 + 16 + 25 = 55
+  55)
+
+;; ── 5. Word frequency counter ────────────────────────────────────
+(go-e2e-test "e2e: word-frequency over a sentence"
+  (let ((env (go-e2e-run
+              (list
+                "text := \"the quick brown fox jumps over the lazy dog the\""
+                "words := strings.Split(text, \" \")"
+                "counts := map[string]int{}"
+                "for i, w := range words { counts[w] = counts[w] + 1 }"
+                "the_count := counts[\"the\"]"
+                "fox_count := counts[\"fox\"]"
+                "dog_count := counts[\"dog\"]"))))
+    (list (go-env-lookup env "the_count")
+          (go-env-lookup env "fox_count")
+          (go-env-lookup env "dog_count")))
+  (list 3 1 1))
+
+;; ── 6. Pipeline via channels ─────────────────────────────────────
+(go-e2e-test "e2e: pipeline — generate, square, sum"
+  (let ((env (go-e2e-run
+              (list
+                "func gen(c chan int, n int) { for i := 1; i <= n; i = i + 1 { c <- i } ; close(c) }"
+                "func sq(in chan int, out chan int) { for v := range in { out <- v * v } ; close(out) }"
+                "src := make()"
+                "sqs := make()"
+                "go gen(src, 4)"
+                "go sq(src, sqs)"
+                "total := 0"
+                "for v := range sqs { total = total + v }"))))
+    (go-env-lookup env "total"))
+  ;; 1+4+9+16 = 30
+  30)
+
+;; ── 7. Worker pool draining a job channel ────────────────────────
+(go-e2e-test "e2e: worker pool — sum of doubled jobs"
+  (let ((env (go-e2e-run
+              (list
+                "func worker(jobs chan int, results chan int) { for j := range jobs { results <- j * 2 } }"
+                "jobs := make()"
+                "results := make()"
+                "jobs <- 10 ; jobs <- 20 ; jobs <- 30"
+                "close(jobs)"
+                "go worker(jobs, results)"
+                "close(results)"
+                "sum := 0"
+                "for r := range results { sum = sum + r }"))))
+    (go-env-lookup env "sum"))
+  ;; 20 + 40 + 60 = 120
+  120)
+
+;; ── 8. Bubble sort ───────────────────────────────────────────────
+(go-e2e-test "e2e: bubble sort ascending"
+  (let ((env (go-e2e-run
+              (list
+                "func bubble(xs []int) []int { n := len(xs) ; for i := 0; i < n; i = i + 1 { for j := 0; j < n - 1; j = j + 1 { if xs[j] > xs[j+1] { tmp := xs[j] ; xs[j] = xs[j+1] ; xs[j+1] = tmp } } } ; return xs }"
+                "out := bubble([]int{3, 1, 4, 1, 5, 9, 2, 6})"))))
+    (go-env-lookup env "out"))
+  (list :go-slice (list 1 1 2 3 4 5 6 9)))
+
+;; ── 9. String reverse using strings.Split + reverse + Join ──────
+(go-e2e-test "e2e: reverse words in a sentence"
+  (let ((env (go-e2e-run
+              (list
+                "func rev(xs []string) []string { r := []string{} ; for i := len(xs) - 1; i >= 0; i = i - 1 { r = append(r, xs[i]) } ; return r }"
+                "text := \"go on sx\""
+                "out := strings.Join(rev(strings.Split(text, \" \")), \"-\")"))))
+    (go-env-lookup env "out"))
+  "sx-on-go")
+
+;; ── 10. Counting occurrences via Filter ──────────────────────────
+(go-e2e-test "e2e: count even numbers via Filter+len"
+  (let ((env (go-e2e-run
+              (list
+                "func Filter[T any](xs []T, p func(T) bool) []T { r := []int{} ; for i, v := range xs { if p(v) { r = append(r, v) } } ; return r }"
+                "func gt5(x int) bool { return x > 5 }"
+                "n := len(Filter([]int{1, 2, 6, 3, 7, 8, 4, 9}, gt5))"))))
+    (go-env-lookup env "n"))
+  ;; gt5: 6,7,8,9 = 4
+  4)
+
+;; ── 11. Recursive ackermann (small inputs) ───────────────────────
+(go-e2e-test "e2e: ackermann(2, 3) = 9"
+  (let ((env (go-e2e-run
+              (list
+                "func ack(m int, n int) int { if m == 0 { return n + 1 } ; if n == 0 { return ack(m - 1, 1) } ; return ack(m - 1, ack(m, n - 1)) }"
+                "r := ack(2, 3)"))))
+    (go-env-lookup env "r"))
+  9)
+
+;; ── 12. Defer + recover smoke test ───────────────────────────────
+(go-e2e-test "e2e: defer + recover in real-fn flow"
+  (let ((env (go-e2e-run
+              (list
+                "func safeDivide(a int, b int) int { defer recover() ; if b == 0 { panic(\"div by zero\") } ; return a / b }"
+                "r := safeDivide(10, 0)"
+                "after := 99"))))
+    (go-env-lookup env "after"))
+  99)
+
+(define
+  go-e2e-test-summary
+  (str "e2e " go-e2e-test-pass "/" go-e2e-test-count))

lib/go/tests/eval.sx

@@ -0,0 +1,667 @@
+;; Go evaluator tests.
+
+(define go-eval-test-count 0)
+(define go-eval-test-pass 0)
+(define go-eval-test-fails (list))
+
+(define
+  go-eval-test
+  (fn
+    (name actual expected)
+    (set! go-eval-test-count (+ go-eval-test-count 1))
+    (if
+      (= actual expected)
+      (set! go-eval-test-pass (+ go-eval-test-pass 1))
+      (append! go-eval-test-fails {:name name :expected expected :actual actual}))))
+
+(define gtev (fn (env src) (go-eval env (go-parse src))))
+
+;; ── env ──────────────────────────────────────────────────────────
+(go-eval-test
+  "env: empty lookup returns nil"
+  (go-env-lookup go-env-empty "x")
+  nil)
+
+(go-eval-test
+  "env: extend then lookup"
+  (go-env-lookup (go-env-extend go-env-empty "x" 42) "x")
+  42)
+
+;; ── literals ────────────────────────────────────────────────────
+(go-eval-test "lit: 42 → 42" (gtev go-env-empty "42") 42)
+
+(go-eval-test "lit: 0 → 0" (gtev go-env-empty "0") 0)
+
+(go-eval-test "lit: 0xFF → 255" (gtev go-env-empty "0xFF") 255)
+
+(go-eval-test "lit: 0b1010 → 10" (gtev go-env-empty "0b1010") 10)
+
+(go-eval-test "lit: 0o17 → 15" (gtev go-env-empty "0o17") 15)
+
+(go-eval-test
+  "lit: underscore separator 1_000 → 1000"
+  (gtev go-env-empty "1_000")
+  1000)
+
+(go-eval-test "lit: string" (gtev go-env-empty "\"hello\"") "hello")
+
+;; ── predeclared ─────────────────────────────────────────────────
+(go-eval-test "var: true" (gtev go-env-empty "true") true)
+(go-eval-test "var: false" (gtev go-env-empty "false") false)
+(go-eval-test "var: nil" (gtev go-env-empty "nil") nil)
+
+;; ── variable lookup ─────────────────────────────────────────────
+(go-eval-test
+  "var: bound x → 5"
+  (go-eval (go-env-extend go-env-empty "x" 5) (go-parse "x"))
+  5)
+
+(go-eval-test
+  "var: unbound y → :eval-error"
+  (gtev go-env-empty "y")
+  (list :eval-error :unbound "y"))
+
+;; ── binary ops ─────────────────────────────────────────────────
+(go-eval-test "binop: 1 + 2 → 3" (gtev go-env-empty "1 + 2") 3)
+(go-eval-test "binop: 10 - 4 → 6" (gtev go-env-empty "10 - 4") 6)
+(go-eval-test "binop: 3 * 7 → 21" (gtev go-env-empty "3 * 7") 21)
+(go-eval-test "binop: 42 / 7 → 6" (gtev go-env-empty "42 / 7") 6)
+(go-eval-test
+  "binop: 2 + 3 * 4 → 14 (prec)"
+  (gtev go-env-empty "2 + 3 * 4")
+  14)
+(go-eval-test
+  "binop: a + b uses env"
+  (go-eval
+    (go-env-extend (go-env-extend go-env-empty "a" 3) "b" 4)
+    (go-parse "a + b"))
+  7)
+
+(go-eval-test "binop: 1 < 2 → true" (gtev go-env-empty "1 < 2") true)
+(go-eval-test "binop: 5 == 5 → true" (gtev go-env-empty "5 == 5") true)
+(go-eval-test "binop: 5 != 5 → false" (gtev go-env-empty "5 != 5") false)
+(go-eval-test
+  "binop: true && false → false"
+  (gtev go-env-empty "true && false")
+  false)
+(go-eval-test
+  "binop: false || true → true"
+  (gtev go-env-empty "false || true")
+  true)
+
+;; ── report ──────────────────────────────────────────────────────
+(go-eval-test
+  "var-decl: var x = 5 — env has x=5"
+  (go-env-lookup
+    (go-eval-program go-env-empty (list (go-parse "var x = 5")))
+    "x")
+  5)
+
+(go-eval-test
+  "short-decl: a, b := 3, 4 — env has both"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "a, b := 3, 4")))))
+    (list (go-env-lookup env "a") (go-env-lookup env "b")))
+  (list 3 4))
+
+(go-eval-test
+  "assign: x = 5 then x → 5"
+  (let
+    ((env (go-eval-program (go-env-extend go-env-empty "x" 1) (list (go-parse "x = 5")))))
+    (go-env-lookup env "x"))
+  5)
+
+(go-eval-test
+  "if: true branch evaluates"
+  (let
+    ((env (go-eval-program (go-env-extend go-env-empty "x" 0) (list (go-parse "if true { x = 1 }")))))
+    (go-env-lookup env "x"))
+  1)
+
+(go-eval-test
+  "if-else: false → else branch"
+  (let
+    ((env (go-eval-program (go-env-extend go-env-empty "x" 0) (list (go-parse "if false { x = 1 } else { x = 2 }")))))
+    (go-env-lookup env "x"))
+  2)
+
+(go-eval-test
+  "fn: define + call — double(7) = 14"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "func double(x int) int { return x * 2 }")))))
+    (go-eval env (go-parse "double(7)")))
+  14)
+
+(go-eval-test
+  "fn: add(2, 3) = 5"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "func add(x, y int) int { return x + y }")))))
+    (go-eval env (go-parse "add(2, 3)")))
+  5)
+
+(go-eval-test
+  "fn: recursive fib(5) = 5"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "func fib(n int) int { if n < 2 { return n } return fib(n-1) + fib(n-2) }")))))
+    (go-eval env (go-parse "fib(5)")))
+  5)
+
+(go-eval-test
+  "for: count to 10 with sum"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "var sum = 0") (go-parse "for i := 0; i < 10; i++ { sum = sum + i }")))))
+    (go-env-lookup env "sum"))
+  45)
+
+(go-eval-test
+  "inc-dec: x++ updates env"
+  (let
+    ((env (go-eval-program (go-env-extend go-env-empty "x" 5) (list (go-parse "x++")))))
+    (go-env-lookup env "x"))
+  6)
+
+(go-eval-test
+  "inc-dec: x-- updates env"
+  (let
+    ((env (go-eval-program (go-env-extend go-env-empty "x" 5) (list (go-parse "x--")))))
+    (go-env-lookup env "x"))
+  4)
+
+(go-eval-test
+  "for: break exits the loop"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "var i = 0") (go-parse "for i < 100 { if i == 5 { break } ; i++ }")))))
+    (go-env-lookup env "i"))
+  5)
+
+(go-eval-test
+  "for: continue skips body but runs post"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "var sum = 0") (go-parse "for i := 0; i < 5; i++ { if i == 2 { continue } ; sum = sum + i }")))))
+    (go-env-lookup env "sum"))
+  8)
+
+(go-eval-test
+  "for: infinite + break with sum"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "var s = 0") (go-parse "var i = 1") (go-parse "for { if i > 4 { break } ; s = s + i ; i++ }")))))
+    (go-env-lookup env "s"))
+  10)
+
+(go-eval-test
+  "fn: iterative factorial via for-loop"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "func fact(n int) int { r := 1 ; for i := 2 ; i <= n ; i++ { r = r * i } ; return r }")))))
+    (go-eval env (go-parse "fact(5)")))
+  120)
+
+(go-eval-test
+  "slice: []int{1,2,3} → :go-slice"
+  (gtev go-env-empty "[]int{1, 2, 3}")
+  (list :go-slice (list 1 2 3)))
+
+(go-eval-test
+  "index: a[0] = 10, a[2] = 30"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "a := []int{10, 20, 30}")))))
+    (list (go-eval env (go-parse "a[0]")) (go-eval env (go-parse "a[2]"))))
+  (list 10 30))
+
+(go-eval-test
+  "index: out-of-range error"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "a := []int{1, 2}")))))
+    (go-eval env (go-parse "a[5]")))
+  (list :eval-error :index-out-of-range 5 2))
+
+(go-eval-test
+  "builtin: len(slice) = 3"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "a := []int{1, 2, 3}")))))
+    (go-eval env (go-parse "len(a)")))
+  3)
+
+(go-eval-test
+  "builtin: len(string)"
+  (go-eval go-env-builtins (go-parse "len(\"hello\")"))
+  5)
+
+(go-eval-test
+  "builtin: append(a, 4, 5)"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "a := []int{1, 2, 3}")))))
+    (go-eval env (go-parse "append(a, 4, 5)")))
+  (list
+    :go-slice (list 1 2 3 4 5)))
+
+(go-eval-test
+  "slice expr: a[1:3]"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "a := []int{10, 20, 30, 40}")))))
+    (go-eval env (go-parse "a[1:3]")))
+  (list :go-slice (list 20 30)))
+
+(go-eval-test
+  "slice expr: a[:2] (omitted low)"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "a := []int{1, 2, 3, 4}")))))
+    (go-eval env (go-parse "a[:2]")))
+  (list :go-slice (list 1 2)))
+
+(go-eval-test
+  "slice expr: a[2:] (omitted high)"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "a := []int{1, 2, 3, 4}")))))
+    (go-eval env (go-parse "a[2:]")))
+  (list :go-slice (list 3 4)))
+
+(go-eval-test
+  "fn: sum slice via for-loop with len + index"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "a := []int{1, 2, 3, 4, 5}") (go-parse "sum := 0") (go-parse "for i := 0; i < len(a); i++ { sum = sum + a[i] }")))))
+    (go-env-lookup env "sum"))
+  15)
+
+(go-eval-test
+  "map: map[string]int{...} → :go-map"
+  (gtev go-env-empty "map[string]int{\"a\": 1, \"b\": 2}")
+  (list :go-map (list (list "a" 1) (list "b" 2))))
+
+(go-eval-test
+  "map: m[\"a\"] → 1"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "m := map[string]int{\"a\": 1, \"b\": 2}")))))
+    (go-eval env (go-parse "m[\"a\"]")))
+  1)
+
+(go-eval-test
+  "map: missing key → nil (v0 stand-in for zero value)"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "m := map[string]int{\"a\": 1}")))))
+    (go-eval env (go-parse "m[\"missing\"]")))
+  nil)
+
+(go-eval-test
+  "map: len(m) = 2"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "m := map[string]int{\"a\": 1, \"b\": 2}")))))
+    (go-eval env (go-parse "len(m)")))
+  2)
+
+(go-eval-test
+  "map: index-assign updates existing key"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "m := map[string]int{\"a\": 1}") (go-parse "m[\"a\"] = 99")))))
+    (go-eval env (go-parse "m[\"a\"]")))
+  99)
+
+(go-eval-test
+  "map: index-assign adds new key"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "m := map[string]int{}") (go-parse "m[\"new\"] = 7")))))
+    (go-eval env (go-parse "m[\"new\"]")))
+  7)
+
+(go-eval-test
+  "slice: index-assign a[0] = 99"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "a := []int{10, 20, 30}") (go-parse "a[0] = 99")))))
+    (go-eval env (go-parse "a[0]")))
+  99)
+
+(go-eval-test
+  "map: word count via loop"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "words := []string{\"a\", \"b\", \"a\", \"c\", \"a\"}") (go-parse "counts := map[string]int{}") (go-parse "for i := 0; i < len(words); i++ { counts[words[i]] = counts[words[i]] + 1 }")))))
+    (go-eval env (go-parse "counts[\"a\"]")))
+  3)
+
+(go-eval-test
+  "type-decl: registers struct field names"
+  (go-env-lookup
+    (go-eval-program
+      go-env-empty
+      (list (go-parse "type Point struct { x, y int }")))
+    "Point")
+  (list :go-struct-type (list "x" "y")))
+
+(go-eval-test
+  "struct: positional composite Point{1, 2}"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "type Point struct { x, y int }")))))
+    (go-eval env (go-parse "Point{1, 2}")))
+  (list
+    :go-struct "Point"
+    (list (list "x" 1) (list "y" 2))))
+
+(go-eval-test
+  "struct: keyed composite Point{x: 5, y: 10}"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "type Point struct { x, y int }")))))
+    (go-eval env (go-parse "Point{x: 5, y: 10}")))
+  (list
+    :go-struct "Point"
+    (list (list "x" 5) (list "y" 10))))
+
+(go-eval-test
+  "struct: selector p.x = 1"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "type Point struct { x, y int }") (go-parse "p := Point{1, 2}")))))
+    (go-eval env (go-parse "p.x")))
+  1)
+
+(go-eval-test
+  "struct: selector p.y = 2"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "type Point struct { x, y int }") (go-parse "p := Point{1, 2}")))))
+    (go-eval env (go-parse "p.y")))
+  2)
+
+(go-eval-test
+  "struct: selector-assign p.x = 99"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "type Point struct { x, y int }") (go-parse "p := Point{1, 2}") (go-parse "p.x = 99")))))
+    (go-eval env (go-parse "p.x")))
+  99)
+
+(go-eval-test
+  "struct: positional arity-mismatch"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "type Point struct { x, y int }")))))
+    (go-eval env (go-parse "Point{1}")))
+  (list :eval-error :struct-arity-mismatch "Point" 2 1))
+
+(go-eval-test
+  "struct: function takes/returns struct"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "type Point struct { x, y int }") (go-parse "func add(a, b Point) Point { return Point{a.x + b.x, a.y + b.y} }")))))
+    (go-eval env (go-parse "add(Point{1, 2}, Point{3, 4})")))
+  (list
+    :go-struct "Point"
+    (list (list "x" 4) (list "y" 6))))
+
+(go-eval-test
+  "method: p.Sum() = 3"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "type Point struct { x, y int }") (go-parse "func (p Point) Sum() int { return p.x + p.y }") (go-parse "p := Point{1, 2}")))))
+    (go-eval env (go-parse "p.Sum()")))
+  3)
+
+(go-eval-test
+  "method: p.Add(5) = 6 (with arg)"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "type Point struct { x, y int }") (go-parse "func (p Point) Add(d int) int { return p.x + d }") (go-parse "p := Point{1, 2}")))))
+    (go-eval env (go-parse "p.Add(5)")))
+  6)
+
+(go-eval-test
+  "method: pointer receiver works value-style in v0"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "type Point struct { x, y int }") (go-parse "func (p *Point) GetX() int { return p.x }") (go-parse "p := Point{1, 2}")))))
+    (go-eval env (go-parse "p.GetX()")))
+  1)
+
+(go-eval-test
+  "method: missing method → :no-such-method"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "type Point struct { x, y int }") (go-parse "p := Point{1, 2}")))))
+    (go-eval env (go-parse "p.Ghost()")))
+  (list :eval-error :no-such-method "Point" "Ghost"))
+
+(go-eval-test
+  "unary: -x"
+  (go-eval (go-env-extend go-env-empty "x" 5) (go-parse "-x"))
+  -5)
+
+(go-eval-test "unary: !true → false" (gtev go-env-empty "!true") false)
+
+(go-eval-test "unary: !false → true" (gtev go-env-empty "!false") true)
+
+(go-eval-test
+  "unary: -3 + 5 = 2 (unary binds tighter)"
+  (gtev go-env-empty "-3 + 5")
+  2)
+
+(go-eval-test
+  "e2e: count odd numbers in 1..10 = 5"
+  (let
+    ((env (go-eval-program go-env-empty
+            (list (go-parse "odds := 0")
+                  (go-parse "i := 1")
+                  (go-parse "for i <= 10 { odds = odds + 1; i = i + 2 }")))))
+    (go-env-lookup env "odds"))
+  5)
+
+(go-eval-test
+  "e2e: factorial via method on Counter"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "type Acc struct { v int }") (go-parse "func (a Acc) Mul(x int) Acc { return Acc{a.v * x} }") (go-parse "a := Acc{1}") (go-parse "for i := 1; i <= 5; i++ { a = a.Mul(i) }")))))
+    (go-eval env (go-parse "a.v")))
+  120)
+
+(go-eval-test
+  "e2e: recursive fibonacci fib(10) = 55"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "func fib(n int) int { if n < 2 { return n } return fib(n-1) + fib(n-2) }")))))
+    (go-eval env (go-parse "fib(10)")))
+  55)
+
+(go-eval-test
+  "e2e: struct + method + iterative loop"
+  (let
+    ((env (go-eval-program go-env-empty (list (go-parse "type Counter struct { n int }") (go-parse "func (c Counter) Bump() Counter { return Counter{c.n + 1} }") (go-parse "c := Counter{0}") (go-parse "for i := 0; i < 7; i++ { c = c.Bump() }")))))
+    (go-eval env (go-parse "c.n")))
+  7)
+
+(go-eval-test
+  "e2e: linear search returns index"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func find(a []int, x int) int { for i := 0; i < len(a); i++ { if a[i] == x { return i } } ; return -1 }") (go-parse "nums := []int{10, 20, 30, 40}")))))
+    (go-eval env (go-parse "find(nums, 30)")))
+  2)
+
+(go-eval-test
+  "e2e: linear search returns -1 when missing"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func find(a []int, x int) int { for i := 0; i < len(a); i++ { if a[i] == x { return i } } ; return -1 }") (go-parse "nums := []int{10, 20, 30}")))))
+    (go-eval env (go-parse "find(nums, 99)")))
+  -1)
+
+(go-eval-test
+  "defer: single defer runs after surrounding fn body returns"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "func push2(c chan int) { c <- 2 }") (go-parse "func run(c chan int) { defer push2(c) ; c <- 1 }") (go-parse "run(ch)") (go-parse "first := <-ch") (go-parse "second := <-ch")))))
+    (list (go-env-lookup env "first") (go-env-lookup env "second")))
+  (list 1 2))
+
+(go-eval-test
+  "defer: multiple defers run LIFO"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "func p2(c chan int) { c <- 2 }") (go-parse "func p3(c chan int) { c <- 3 }") (go-parse "func run(c chan int) { defer p2(c) ; defer p3(c) ; c <- 1 }") (go-parse "run(ch)") (go-parse "a := <-ch") (go-parse "b := <-ch") (go-parse "d := <-ch")))))
+    (list
+      (go-env-lookup env "a")
+      (go-env-lookup env "b")
+      (go-env-lookup env "d")))
+  (list 1 3 2))
+
+(go-eval-test
+  "defer: arguments are evaluated at defer-time (not call-time)"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "func pushN(c chan int, v int) { c <- v }") (go-parse "func run(c chan int) { x := 7 ; defer pushN(c, x) ; x = 99 }") (go-parse "run(ch)") (go-parse "got := <-ch")))))
+    (go-env-lookup env "got"))
+  7)
+
+(go-eval-test
+  "defer: runs even when fn returns early via return"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "func note(c chan int) { c <- 42 }") (go-parse "func run(c chan int) int { defer note(c) ; return 1 }") (go-parse "r := run(ch)") (go-parse "n := <-ch")))))
+    (list (go-env-lookup env "r") (go-env-lookup env "n")))
+  (list 1 42))
+
+(go-eval-test
+  "defer: stack is frame-local — outer defers don't run on inner return"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "func push1(c chan int) { c <- 1 }") (go-parse "func push2(c chan int) { c <- 2 }") (go-parse "func inner(c chan int) { defer push2(c) }") (go-parse "func outer(c chan int) { defer push1(c) ; inner(c) }") (go-parse "outer(ch)") (go-parse "a := <-ch") (go-parse "b := <-ch")))))
+    (list (go-env-lookup env "a") (go-env-lookup env "b")))
+  (list 2 1))
+
+(go-eval-test
+  "defer: in a loop, all defers fire on fn return (not loop iter)"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "func pushI(c chan int, v int) { c <- v }") (go-parse "func loop(c chan int) { for i := 0; i < 4; i = i + 1 { defer pushI(c, i) } }") (go-parse "loop(ch)") (go-parse "a := <-ch") (go-parse "b := <-ch") (go-parse "d := <-ch") (go-parse "e := <-ch")))))
+    (list
+      (go-env-lookup env "a")
+      (go-env-lookup env "b")
+      (go-env-lookup env "d")
+      (go-env-lookup env "e")))
+  (list 3 2 1 0))
+
+(go-eval-test
+  "panic: uncaught panic surfaces as (:go-panic V) from program"
+  (let
+    ((r (go-eval-program go-env-builtins (list (go-parse "panic(\"boom\")")))))
+    r)
+  (list :go-panic "boom"))
+
+(go-eval-test
+  "panic inside fn: surfaces from fn call too"
+  (let
+    ((r (go-eval-program go-env-builtins (list (go-parse "func boom() { panic(\"oops\") }") (go-parse "boom()")))))
+    r)
+  (list :go-panic "oops"))
+
+(go-eval-test
+  "recover: deferred recover swallows panic, fn returns normally"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func safe() { defer recover() ; panic(\"x\") }") (go-parse "safe()") (go-parse "after := 42")))))
+    (go-env-lookup env "after"))
+  42)
+
+(go-eval-test
+  "recover: deferred recover captures the panic value"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "func grab(c chan int) { r := recover() ; c <- r }") (go-parse "func safe(c chan int) { defer grab(c) ; panic(99) }") (go-parse "safe(ch)") (go-parse "got := <-ch")))))
+    (go-env-lookup env "got"))
+  99)
+
+(go-eval-test
+  "panic: propagates through intermediate frames without defers"
+  (let
+    ((r (go-eval-program go-env-builtins (list (go-parse "func inner() { panic(\"deep\") }") (go-parse "func middle() { inner() }") (go-parse "func outer() { middle() }") (go-parse "outer()")))))
+    r)
+  (list :go-panic "deep"))
+
+(go-eval-test
+  "recover: middle-frame defer catches panic from deeper frame"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func inner() { panic(\"deep\") }") (go-parse "func middle() { inner() }") (go-parse "func outer() { defer recover() ; middle() }") (go-parse "outer()") (go-parse "after := 7")))))
+    (go-env-lookup env "after"))
+  7)
+
+(go-eval-test
+  "goroutine panic: surfaces synchronously back to spawner (v0)"
+  (let
+    ((r (go-eval-program go-env-builtins (list (go-parse "func boom() { panic(\"goroutine\") }") (go-parse "go boom()")))))
+    r)
+  (list :go-panic "goroutine"))
+
+(go-eval-test
+  "goroutine panic + spawner-defer-recover catches it (v0 sync)"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func boom() { panic(\"g\") }") (go-parse "func main() { defer recover() ; go boom() }") (go-parse "main()") (go-parse "after := 11")))))
+    (go-env-lookup env "after"))
+  11)
+
+(go-eval-test
+  "defer order with recover: all defers run, recover catches"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "func p2(c chan int) { c <- 2 }") (go-parse "func rec(c chan int) { recover() ; c <- 7 }") (go-parse "func safe(c chan int) { defer p2(c) ; defer rec(c) ; panic(0) }") (go-parse "safe(ch)") (go-parse "a := <-ch") (go-parse "b := <-ch")))))
+    (list (go-env-lookup env "a") (go-env-lookup env "b")))
+  (list 7 2))
+
+(go-eval-test
+  "defer fires when fn panics (not just normal return)"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "func note(c chan int) { c <- 5 }") (go-parse "func safe(c chan int) { defer note(c) ; defer recover() ; panic(\"!\") }") (go-parse "safe(ch)") (go-parse "got := <-ch")))))
+    (go-env-lookup env "got"))
+  5)
+
+(go-eval-test
+  "panic with nil value: still surfaces as (:go-panic nil)"
+  (let
+    ((r (go-eval-program go-env-builtins (list (go-parse "panic(nil)")))))
+    r)
+  (list :go-panic nil))
+
+(go-eval-test
+  "panic inside loop body: aborts loop + propagates"
+  (let
+    ((r (go-eval-program go-env-builtins (list (go-parse "func find(x int) { for i := 0; i < 10; i = i + 1 { if i == x { panic(i) } } }") (go-parse "find(3)")))))
+    r)
+  (list :go-panic 3))
+
+(go-eval-test
+  "defer in panicking fn: still runs even though no return reached"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "func mark(c chan int) { c <- 8 }") (go-parse "func inner(c chan int) { defer mark(c) ; panic(\"!\") }") (go-parse "func outer(c chan int) { defer recover() ; inner(c) }") (go-parse "outer(ch)") (go-parse "got := <-ch")))))
+    (go-env-lookup env "got"))
+  8)
+
+(go-eval-test
+  "defer fn captures args by value, not reference (re-confirm)"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "func pushN(c chan int, v int) { c <- v }") (go-parse "func run(c chan int) { defer recover() ; x := 5 ; defer pushN(c, x) ; x = 999 ; panic(\"k\") }") (go-parse "run(ch)") (go-parse "got := <-ch")))))
+    (go-env-lookup env "got"))
+  5)
+
+(go-eval-test
+  "generic: identity Id[T any](x) returns x at runtime"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func Id[T any](x T) T { return x }") (go-parse "r := Id(42)")))))
+    (go-env-lookup env "r"))
+  42)
+
+(go-eval-test
+  "generic: Id works with strings (type erasure)"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func Id[T any](x T) T { return x }") (go-parse "r := Id(\"hi\")")))))
+    (go-env-lookup env "r"))
+  "hi")
+
+(go-eval-test
+  "generic: Map[T, U] over []int with double — produces []int"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func Map[T any, U any](xs []T, f func(T) U) []U { r := []int{} ; for i, v := range xs { r = append(r, f(v)) } ; return r }") (go-parse "func dbl(x int) int { return x * 2 }") (go-parse "out := Map([]int{1, 2, 3}, dbl)") (go-parse "first := out[0]") (go-parse "second := out[1]") (go-parse "third := out[2]")))))
+    (list
+      (go-env-lookup env "first")
+      (go-env-lookup env "second")
+      (go-env-lookup env "third")))
+  (list 2 4 6))
+
+(go-eval-test
+  "generic: Filter[T any] keeps elements satisfying predicate"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func Filter[T any](xs []T, p func(T) bool) []T { r := []int{} ; for i, v := range xs { if p(v) { r = append(r, v) } } ; return r }") (go-parse "func gt3(x int) bool { return x > 3 }") (go-parse "out := Filter([]int{1, 2, 3, 4, 5, 6}, gt3)") (go-parse "n := len(out)") (go-parse "first := out[0]") (go-parse "last := out[2]")))))
+    (list
+      (go-env-lookup env "n")
+      (go-env-lookup env "first")
+      (go-env-lookup env "last")))
+  (list 3 4 6))
+
+(go-eval-test
+  "generic: Reduce[T, U] sums []int with seed 0"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func Reduce[T any, U any](xs []T, seed U, f func(U, T) U) U { acc := seed ; for i, v := range xs { acc = f(acc, v) } ; return acc }") (go-parse "func add(a int, b int) int { return a + b }") (go-parse "total := Reduce([]int{10, 20, 30, 40}, 0, add)")))))
+    (go-env-lookup env "total"))
+  100)
+
+(go-eval-test
+  "generic: First[T any]([]T) T returns element zero"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func First[T any](xs []T) T { return xs[0] }") (go-parse "v := First([]int{42, 99})")))))
+    (go-env-lookup env "v"))
+  42)
+
+(define
+  go-eval-test-summary
+  (str "eval " go-eval-test-pass "/" go-eval-test-count))

lib/go/tests/lex.sx

@@ -0,0 +1,339 @@
+;; Go tokenizer tests.
+
+(define go-test-count 0)
+(define go-test-pass 0)
+(define go-test-fails (list))
+
+(define gtok-type (fn (t) (get t :type)))
+(define gtok-value (fn (t) (get t :value)))
+(define tok-types (fn (src) (map gtok-type (go-tokenize src))))
+(define tok-values (fn (src) (map gtok-value (go-tokenize src))))
+
+(define
+  go-test
+  (fn
+    (name actual expected)
+    (set! go-test-count (+ go-test-count 1))
+    (if
+      (= actual expected)
+      (set! go-test-pass (+ go-test-pass 1))
+      (append! go-test-fails {:name name :expected expected :actual actual}))))
+
+;; ── empty / whitespace ────────────────────────────────────────────
+(go-test "empty source" (tok-types "") (list "eof"))
+(go-test "spaces only" (tok-types "   ") (list "eof"))
+(go-test "tabs only" (tok-types "\t\t") (list "eof"))
+(go-test
+  "newline only — no prior token, no ASI"
+  (tok-types "\n")
+  (list "eof"))
+
+;; ── identifiers ───────────────────────────────────────────────────
+(go-test "ident: simple" (tok-values "foo") (list "foo" "\n" nil))
+(go-test
+  "ident: underscore prefix"
+  (tok-values "_bar")
+  (list "_bar" "\n" nil))
+(go-test "ident: mixed case" (tok-values "fooBar") (list "fooBar" "\n" nil))
+(go-test "ident: with digits" (tok-values "x123") (list "x123" "\n" nil))
+(go-test "ident: type tag" (tok-types "foo") (list "ident" "semi" "eof"))
+
+;; ── keywords (all 25) ─────────────────────────────────────────────
+(go-test "kw: break" (tok-types "break") (list "keyword" "semi" "eof"))
+(go-test "kw: case" (tok-types "case") (list "keyword" "eof"))
+(go-test "kw: chan" (tok-types "chan") (list "keyword" "eof"))
+(go-test "kw: const" (tok-types "const") (list "keyword" "eof"))
+(go-test "kw: continue" (tok-types "continue") (list "keyword" "semi" "eof"))
+(go-test "kw: default" (tok-types "default") (list "keyword" "eof"))
+(go-test "kw: defer" (tok-types "defer") (list "keyword" "eof"))
+(go-test "kw: else" (tok-types "else") (list "keyword" "eof"))
+(go-test
+  "kw: fallthrough"
+  (tok-types "fallthrough")
+  (list "keyword" "semi" "eof"))
+(go-test "kw: for" (tok-types "for") (list "keyword" "eof"))
+(go-test "kw: func" (tok-types "func") (list "keyword" "eof"))
+(go-test "kw: go" (tok-types "go") (list "keyword" "eof"))
+(go-test "kw: goto" (tok-types "goto") (list "keyword" "eof"))
+(go-test "kw: if" (tok-types "if") (list "keyword" "eof"))
+(go-test "kw: import" (tok-types "import") (list "keyword" "eof"))
+(go-test "kw: interface" (tok-types "interface") (list "keyword" "eof"))
+(go-test "kw: map" (tok-types "map") (list "keyword" "eof"))
+(go-test "kw: package" (tok-types "package") (list "keyword" "eof"))
+(go-test "kw: range" (tok-types "range") (list "keyword" "eof"))
+(go-test "kw: return" (tok-types "return") (list "keyword" "semi" "eof"))
+(go-test "kw: select" (tok-types "select") (list "keyword" "eof"))
+(go-test "kw: struct" (tok-types "struct") (list "keyword" "eof"))
+(go-test "kw: switch" (tok-types "switch") (list "keyword" "eof"))
+(go-test "kw: type" (tok-types "type") (list "keyword" "eof"))
+(go-test "kw: var" (tok-types "var") (list "keyword" "eof"))
+
+;; ── integer literals — decimal ────────────────────────────────────
+(go-test "int: zero" (tok-values "0") (list "0" "\n" nil))
+(go-test "int: small" (tok-values "42") (list "42" "\n" nil))
+(go-test "int: bigger" (tok-values "123456") (list "123456" "\n" nil))
+(go-test "int: type" (tok-types "42") (list "int" "semi" "eof"))
+
+;; ── integer literals — prefixed + underscores ─────────────────────
+(go-test "int: hex lower" (tok-values "0x1f") (list "0x1f" "\n" nil))
+(go-test "int: hex upper-x" (tok-values "0X1F") (list "0X1F" "\n" nil))
+(go-test
+  "int: hex mixed digits"
+  (tok-values "0xDEADbeef")
+  (list "0xDEADbeef" "\n" nil))
+(go-test "int: binary lower" (tok-values "0b1010") (list "0b1010" "\n" nil))
+(go-test "int: binary upper" (tok-values "0B1101") (list "0B1101" "\n" nil))
+(go-test "int: octal modern" (tok-values "0o755") (list "0o755" "\n" nil))
+(go-test "int: octal upper" (tok-values "0O17") (list "0O17" "\n" nil))
+(go-test "int: octal legacy" (tok-values "0755") (list "0755" "\n" nil))
+(go-test "int: hex type" (tok-types "0x1F") (list "int" "semi" "eof"))
+(go-test "int: bin type" (tok-types "0b101") (list "int" "semi" "eof"))
+(go-test
+  "int: dec underscore"
+  (tok-values "1_000_000")
+  (list "1_000_000" "\n" nil))
+(go-test
+  "int: hex underscore"
+  (tok-values "0xDEAD_BEEF")
+  (list "0xDEAD_BEEF" "\n" nil))
+(go-test
+  "int: bin underscore"
+  (tok-values "0b1010_1010")
+  (list "0b1010_1010" "\n" nil))
+(go-test
+  "int: hex then +"
+  (tok-types "0xFF + 1")
+  (list "int" "op" "int" "semi" "eof"))
+
+;; ── float literals (Go spec § Floating-point literals) ────────────
+(go-test "float: simple" (tok-values "3.14") (list "3.14" "\n" nil))
+(go-test "float: trailing dot" (tok-values "1.") (list "1." "\n" nil))
+(go-test "float: leading dot" (tok-values ".5") (list ".5" "\n" nil))
+(go-test "float: exp lower" (tok-values "1e10") (list "1e10" "\n" nil))
+(go-test "float: exp upper" (tok-values "1E5") (list "1E5" "\n" nil))
+(go-test "float: exp negative" (tok-values "1.5e-3") (list "1.5e-3" "\n" nil))
+(go-test "float: exp positive" (tok-values "2.0e+2") (list "2.0e+2" "\n" nil))
+(go-test "float: zero" (tok-values "0.0") (list "0.0" "\n" nil))
+(go-test "float: dot-only-exp" (tok-values ".5e2") (list ".5e2" "\n" nil))
+(go-test "float: underscore" (tok-values "1_000.5") (list "1_000.5" "\n" nil))
+(go-test "float: type" (tok-types "3.14") (list "float" "semi" "eof"))
+(go-test
+  "float: trailing dot type"
+  (tok-types "1.")
+  (list "float" "semi" "eof"))
+(go-test
+  "float: exp-only type"
+  (tok-types "1e10")
+  (list "float" "semi" "eof"))
+(go-test
+  "float: then +"
+  (tok-types "3.14 + 0.1")
+  (list "float" "op" "float" "semi" "eof"))
+(go-test
+  "float: greedy 1.method"
+  (tok-types "1.method")
+  (list "float" "ident" "semi" "eof"))
+
+;; ── imaginary literals (Go spec § Imaginary literals) ─────────────
+(go-test "imag: int i" (tok-values "2i") (list "2i" "\n" nil))
+(go-test "imag: float i" (tok-values "3.14i") (list "3.14i" "\n" nil))
+(go-test "imag: exp i" (tok-values "1e2i") (list "1e2i" "\n" nil))
+(go-test "imag: int-i type" (tok-types "2i") (list "imag" "semi" "eof"))
+(go-test "imag: float-i type" (tok-types "3.14i") (list "imag" "semi" "eof"))
+(go-test "imag: ASI at newline" (tok-types "1i\n") (list "imag" "semi" "eof"))
+
+;; ── string literals ───────────────────────────────────────────────
+(go-test "raw: simple" (tok-values "`hello`") (list "hello" "\n" nil))
+(go-test "raw: empty" (tok-values "``") (list "" "\n" nil))
+(go-test
+  "raw: backslash literal — no escape processing"
+  (tok-values "`a\\nb`")
+  (list "a\\nb" "\n" nil))
+(go-test
+  "raw: multi-line"
+  (tok-values "`line1\nline2`")
+  (list "line1\nline2" "\n" nil))
+(go-test
+  "raw: contains double-quote"
+  (tok-values "`say \"hi\"`")
+  (list "say \"hi\"" "\n" nil))
+(go-test
+  "raw: CR stripped (Go spec § String literals)"
+  (tok-values "`a\r\nb`")
+  (list "a\nb" "\n" nil))
+(go-test "raw: type" (tok-types "`x`") (list "string" "semi" "eof"))
+
+;; ── rune literals ─────────────────────────────────────────────────
+(go-test
+  "raw: then +"
+  (tok-types "`x` + 1")
+  (list "string" "op" "int" "semi" "eof"))
+(go-test
+  "raw: ASI at newline after"
+  (tok-types "`abc`\n")
+  (list "string" "semi" "eof"))
+(go-test "string: empty" (tok-values "\"\"") (list "" "\n" nil))
+
+;; ── comments ──────────────────────────────────────────────────────
+(go-test "string: hello" (tok-values "\"hello\"") (list "hello" "\n" nil))
+(go-test
+  "string: with space"
+  (tok-values "\"hi there\"")
+  (list "hi there" "\n" nil))
+(go-test "string: escape n" (tok-values "\"a\\nb\"") (list "a\nb" "\n" nil))
+(go-test "string: escape quote" (tok-values "\"a\\\"b\"") (list "a\"b" "\n" nil))
+(go-test
+  "string: escape backslash"
+  (tok-values "\"a\\\\b\"")
+  (list "a\\b" "\n" nil))
+
+;; ── operators & punctuation ───────────────────────────────────────
+(go-test "string: type" (tok-types "\"x\"") (list "string" "semi" "eof"))
+(go-test "rune: simple" (tok-values "'a'") (list "a" "\n" nil))
+(go-test "rune: escape" (tok-values "'\\n'") (list "\n" "\n" nil))
+(go-test "rune: type" (tok-types "'a'") (list "rune" "semi" "eof"))
+(go-test "line comment" (tok-types "// ignored") (list "eof"))
+(go-test "line comment then code" (tok-values "// hi\nx") (list "x" "\n" nil))
+(go-test "block comment" (tok-types "/* a b c */") (list "eof"))
+(go-test
+  "block comment inline"
+  (tok-values "x /* mid */ y")
+  (list "x" "y" "\n" nil))
+(go-test
+  "block comment with newline — ASI"
+  (tok-types "x /* multi\nline */ y")
+  (list "ident" "semi" "ident" "semi" "eof"))
+
+;; ── automatic semicolon insertion (Go spec § Semicolons) ──────────
+(go-test
+  "ops: arithmetic"
+  (tok-values "+ - * / %")
+  (list "+" "-" "*" "/" "%" nil))
+(go-test
+  "ops: comparison"
+  (tok-values "== != < > <= >=")
+  (list "==" "!=" "<" ">" "<=" ">=" nil))
+(go-test "ops: logical" (tok-values "&& || !") (list "&&" "||" "!" nil))
+(go-test
+  "ops: assign forms"
+  (tok-values "= := += -=")
+  (list "=" ":=" "+=" "-=" nil))
+(go-test "ops: channel arrow" (tok-values "<- chan") (list "<-" "chan" nil))
+(go-test "ops: incdec ASI" (tok-types "++ --") (list "op" "op" "semi" "eof"))
+(go-test "ops: ellipsis" (tok-values "...") (list "..." nil))
+(go-test
+  "punct: all brackets"
+  (tok-values "( ) { } [ ]")
+  (list "(" ")" "{" "}" "[" "]" "\n" nil))
+(go-test
+  "punct: comma colon dot"
+  (tok-values ", : .")
+  (list "," ":" "." nil))
+(go-test
+  "op-audit: tilde (generics type-set)"
+  (tok-values "~int")
+  (list "~" "int" "\n" nil))
+(go-test
+  "op-audit: all arithmetic + assignment"
+  (tok-values "+ - * / % += -= *= /= %=")
+  (list "+" "-" "*" "/" "%" "+=" "-=" "*=" "/=" "%=" nil))
+(go-test
+  "op-audit: all bitwise + assignment"
+  (tok-values "& | ^ << >> &^ &= |= ^= <<= >>= &^=")
+  (list "&" "|" "^" "<<" ">>" "&^" "&=" "|=" "^=" "<<=" ">>=" "&^=" nil))
+(go-test
+  "op-audit: all comparison + logical"
+  (tok-values "== != < > <= >= && || !")
+  (list "==" "!=" "<" ">" "<=" ">=" "&&" "||" "!" nil))
+(go-test
+  "op-audit: assign / decls / arrows / variadic / inc-dec"
+  (tok-values "= := <- ++ -- ...")
+  (list "=" ":=" "<-" "++" "--" "..." nil))
+
+;; ── short program ─────────────────────────────────────────────────
+(go-test
+  "op-audit: punctuation"
+  (tok-values "( ) [ ] { } , . :")
+  (list "(" ")" "[" "]" "{" "}" "," "." ":" nil))
+(go-test
+  "ASI: after ident at newline"
+  (tok-types "x\ny")
+  (list "ident" "semi" "ident" "semi" "eof"))
+(go-test "ASI: after int" (tok-types "42\n") (list "int" "semi" "eof"))
+
+;; ── report ────────────────────────────────────────────────────────
+(go-test "ASI: after float" (tok-types "3.14\n") (list "float" "semi" "eof"))
+
+(go-test
+  "ASI: after string"
+  (tok-types "\"hi\"\n")
+  (list "string" "semi" "eof"))
+
+(go-test "ASI: after rune" (tok-types "'a'\n") (list "rune" "semi" "eof"))
+
+(go-test
+  "ASI: after )"
+  (tok-types "f()\n")
+  (list "ident" "op" "op" "semi" "eof"))
+
+(go-test
+  "ASI: after ]"
+  (tok-types "x[0]\n")
+  (list "ident" "op" "int" "op" "semi" "eof"))
+
+(go-test "ASI: after }" (tok-types "{}\n") (list "op" "op" "semi" "eof"))
+
+(go-test "ASI: after ++" (tok-types "i++\n") (list "ident" "op" "semi" "eof"))
+
+(go-test
+  "ASI: NOT after +"
+  (tok-types "x +\ny")
+  (list "ident" "op" "ident" "semi" "eof"))
+
+(go-test
+  "ASI: NOT after ("
+  (tok-types "f(\nx)")
+  (list "ident" "op" "ident" "op" "semi" "eof"))
+
+(go-test
+  "ASI: blank lines collapse — single semi only"
+  (tok-types "x\n\n\ny")
+  (list "ident" "semi" "ident" "semi" "eof"))
+
+(go-test
+  "ASI: at EOF after ident"
+  (tok-types "x")
+  (list "ident" "semi" "eof"))
+
+(go-test
+  "ASI: explicit semi"
+  (tok-types "x;y")
+  (list "ident" "semi" "ident" "semi" "eof"))
+
+(go-test
+  "short-decl: x := 42 (types)"
+  (tok-types "x := 42")
+  (list "ident" "op" "int" "semi" "eof"))
+
+(go-test
+  "short-decl: x := 42 (values)"
+  (tok-values "x := 42")
+  (list "x" ":=" "42" "\n" nil))
+
+(go-test
+  "func decl shape"
+  (tok-types "func foo() int { return 0 }")
+  (list
+    "keyword"
+    "ident"
+    "op"
+    "op"
+    "ident"
+    "op"
+    "keyword"
+    "int"
+    "op"
+    "semi"
+    "eof"))
+
+(define go-lex-test-summary (str "lex " go-test-pass "/" go-test-count))

lib/go/tests/runtime.sx

@@ -0,0 +1,311 @@
+;; Go runtime tests — goroutines + channels.
+
+(define go-rt-test-count 0)
+(define go-rt-test-pass 0)
+(define go-rt-test-fails (list))
+
+(define
+  go-rt-test
+  (fn
+    (name actual expected)
+    (set! go-rt-test-count (+ go-rt-test-count 1))
+    (if
+      (= actual expected)
+      (set! go-rt-test-pass (+ go-rt-test-pass 1))
+      (append! go-rt-test-fails {:name name :expected expected :actual actual}))))
+
+;; ── channel primitives (direct API, no source parsing) ─────────
+(go-rt-test "chan: make returns a chan value" (go-chan? (go-make-chan)) true)
+
+(go-rt-test
+  "chan: distinct channels have distinct identity"
+  (= (go-make-chan) (go-make-chan))
+  false)
+
+(go-rt-test
+  "chan: send + recv round-trip"
+  (let
+    ((ch (go-make-chan)))
+    (go-chan-send! ch 42)
+    (go-chan-recv! ch))
+  42)
+
+(go-rt-test
+  "chan: empty recv returns :empty marker"
+  (let ((ch (go-make-chan))) (go-chan-recv! ch))
+  :empty)
+
+(go-rt-test
+  "chan: FIFO order"
+  (let
+    ((ch (go-make-chan)))
+    (go-chan-send! ch 1)
+    (go-chan-send! ch 2)
+    (go-chan-send! ch 3)
+    (list (go-chan-recv! ch) (go-chan-recv! ch) (go-chan-recv! ch)))
+  (list 1 2 3))
+
+(go-rt-test
+  "chan: closed? flag flips"
+  (let
+    ((ch (go-make-chan)))
+    (let
+      ((before (go-chan-closed? ch)))
+      (go-chan-close! ch)
+      (list before (go-chan-closed? ch))))
+  (list false true))
+
+;; ── source-level: make / send / recv / close ───────────────────
+(go-rt-test
+  "src: ch := make() returns chan"
+  (go-chan?
+    (let
+      ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()")))))
+      (go-env-lookup env "ch")))
+  true)
+
+(go-rt-test
+  "src: ch <- 5 then <-ch = 5"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "ch <- 5")))))
+    (go-eval env (go-parse "<-ch")))
+  5)
+
+(go-rt-test
+  "src: go + chan ping-pong"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func sender(c chan int) { c <- 99 }") (go-parse "ch := make()") (go-parse "go sender(ch)")))))
+    (go-eval env (go-parse "<-ch")))
+  99)
+
+(go-rt-test
+  "src: close(ch) marks it closed"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "close(ch)")))))
+    (go-chan-closed? (go-env-lookup env "ch")))
+  true)
+
+(go-rt-test
+  "src: multiple goroutines feeding one channel"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func push(c chan int, v int) { c <- v }") (go-parse "ch := make()") (go-parse "go push(ch, 1)") (go-parse "go push(ch, 2)") (go-parse "go push(ch, 3)")))))
+    (list
+      (go-eval env (go-parse "<-ch"))
+      (go-eval env (go-parse "<-ch"))
+      (go-eval env (go-parse "<-ch"))))
+  (list 1 2 3))
+
+(go-rt-test
+  "src: worker pattern — send sum back"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func work(c chan int, a int, b int) { c <- a + b }") (go-parse "result := make()") (go-parse "go work(result, 7, 13)")))))
+    (go-eval env (go-parse "<-result")))
+  20)
+
+;; ── report ─────────────────────────────────────────────────────
+(go-rt-test
+  "select: default runs when no case is ready"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "x := 0") (go-parse "select { case <-ch: x = 1 ; default: x = 99 }")))))
+    (go-env-lookup env "x"))
+  99)
+
+(go-rt-test
+  "select: recv case fires when ready"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "ch <- 7") (go-parse "x := 0") (go-parse "select { case <-ch: x = 1 ; default: x = 99 }")))))
+    (go-env-lookup env "x"))
+  1)
+
+(go-rt-test
+  "select: recv-into-var binds the value"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "ch <- 42") (go-parse "select { case v := <-ch: v }")))))
+    (go-env-lookup env "v"))
+  42)
+
+(go-rt-test
+  "select: send case (always ready in v0)"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "select { case ch <- 5: }")))))
+    (go-chan-len (go-env-lookup env "ch")))
+  1)
+
+(go-rt-test
+  "select: picks first ready case"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "a := make()") (go-parse "b := make()") (go-parse "b <- 100") (go-parse "x := 0") (go-parse "select { case <-a: x = 1 ; case <-b: x = 2 ; default: x = 99 }")))))
+    (go-env-lookup env "x"))
+  2)
+
+(go-rt-test
+  "select: no default + nothing ready → blocked error"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()")))))
+    (go-eval-stmt env (go-parse "select { case <-ch: }") (list)))
+  (list :eval-error :select-blocked-no-default))
+
+(go-rt-test
+  "select: combined with goroutine fan-in"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func push(c chan int, v int) { c <- v }") (go-parse "ch := make()") (go-parse "go push(ch, 7)") (go-parse "result := 0") (go-parse "select { case v := <-ch: result = v ; default: result = -1 }")))))
+    (go-env-lookup env "result"))
+  7)
+
+(go-rt-test
+  "range: slice — sum of 1..5"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "var sum = 0") (go-parse "a := []int{1, 2, 3, 4, 5}") (go-parse "for i, v := range a { sum = sum + v }")))))
+    (go-env-lookup env "sum"))
+  15)
+
+(go-rt-test
+  "range: slice — key only (index)"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "var s = 0") (go-parse "a := []int{10, 20, 30}") (go-parse "for i := range a { s = s + i }")))))
+    (go-env-lookup env "s"))
+  3)
+
+(go-rt-test
+  "range: map — sum values"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "var s = 0") (go-parse "m := map[string]int{\"a\": 1, \"b\": 2, \"c\": 3}") (go-parse "for k, v := range m { s = s + v }")))))
+    (go-env-lookup env "s"))
+  6)
+
+(go-rt-test
+  "range: channel — collect all buffered"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "ch := make()") (go-parse "ch <- 1") (go-parse "ch <- 2") (go-parse "ch <- 3") (go-parse "var sum = 0") (go-parse "for v := range ch { sum = sum + v }")))))
+    (go-env-lookup env "sum"))
+  6)
+
+(go-rt-test
+  "range: slice with break exits early"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "var s = 0") (go-parse "a := []int{1, 2, 3, 4, 5}") (go-parse "for i, v := range a { if v == 3 { break } ; s = s + v }")))))
+    (go-env-lookup env "s"))
+  3)
+
+(go-rt-test
+  "range: slice with continue skips an element"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "var s = 0") (go-parse "a := []int{1, 2, 3, 4, 5}") (go-parse "for i, v := range a { if v == 3 { continue } ; s = s + v }")))))
+    (go-env-lookup env "s"))
+  12)
+
+(go-rt-test
+  "range: empty slice — body never runs"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "var s = 0") (go-parse "a := []int{}") (go-parse "for v := range a { s = s + v }")))))
+    (go-env-lookup env "s"))
+  0)
+
+(go-rt-test
+  "range: chan + goroutine producer"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func emit(c chan int) { c <- 10 ; c <- 20 ; c <- 30 }") (go-parse "ch := make()") (go-parse "go emit(ch)") (go-parse "var total = 0") (go-parse "for v := range ch { total = total + v }")))))
+    (go-env-lookup env "total"))
+  60)
+
+(go-rt-test
+  "timer: after(d) returns a ready channel (v0 stub)"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "t := after(100)")))))
+    (go-chan-len (go-env-lookup env "t")))
+  1)
+
+(go-rt-test
+  "select with timer (after) — buffered value wins, timer is fallback"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func push99(c chan int) { c <- 99 }") (go-parse "c := make()") (go-parse "go push99(c)") (go-parse "t := after(0)") (go-parse "var v = 0") (go-parse "select { case x := <-c: v = x; case y := <-t: v = -1 }")))))
+    (go-env-lookup env "v"))
+  99)
+
+(go-rt-test
+  "fan-in: 3 producer goroutines, main sums their values"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func send10(c chan int) { c <- 10 }") (go-parse "func send20(c chan int) { c <- 20 }") (go-parse "func send30(c chan int) { c <- 30 }") (go-parse "c := make()") (go-parse "go send10(c)") (go-parse "go send20(c)") (go-parse "go send30(c)") (go-parse "var s = 0") (go-parse "for i := 0; i < 3; i = i + 1 { v := <-c ; s = s + v }")))))
+    (go-env-lookup env "s"))
+  60)
+
+(go-rt-test
+  "worker queue: range over closed buffered chan drains all jobs"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "jobs := make()") (go-parse "jobs <- 1") (go-parse "jobs <- 2") (go-parse "jobs <- 3") (go-parse "jobs <- 4") (go-parse "close(jobs)") (go-parse "var s = 0") (go-parse "for j := range jobs { s = s + j }")))))
+    (go-env-lookup env "s"))
+  10)
+
+(go-rt-test
+  "pipeline: stage1 squares, stage2 sums via channels"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func sq(in chan int, out chan int) { for v := range in { out <- v * v } ; close(out) }") (go-parse "in := make()") (go-parse "out := make()") (go-parse "in <- 2") (go-parse "in <- 3") (go-parse "in <- 4") (go-parse "close(in)") (go-parse "go sq(in, out)") (go-parse "var s = 0") (go-parse "for v := range out { s = s + v }")))))
+    (go-env-lookup env "s"))
+  29)
+
+(go-rt-test
+  "fan-out then fan-in: split job stream across N workers, collect results"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func worker(in chan int, out chan int) { for v := range in { out <- v + 100 } }") (go-parse "jobs := make()") (go-parse "results := make()") (go-parse "jobs <- 1") (go-parse "jobs <- 2") (go-parse "jobs <- 3") (go-parse "close(jobs)") (go-parse "go worker(jobs, results)") (go-parse "close(results)") (go-parse "var s = 0") (go-parse "for r := range results { s = s + r }")))))
+    (go-env-lookup env "s"))
+  306)
+
+(go-rt-test
+  "select: first ready case wins (channel order = source order)"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "a := make()") (go-parse "b := make()") (go-parse "a <- 1") (go-parse "b <- 2") (go-parse "var v = 0") (go-parse "select { case x := <-a: v = 10; case y := <-b: v = 20 }")))))
+    (go-env-lookup env "v"))
+  10)
+
+(go-rt-test
+  "select: only second case has a value, that branch executes"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "a := make()") (go-parse "b := make()") (go-parse "b <- 7") (go-parse "var v = 0") (go-parse "select { case x := <-a: v = -1; case y := <-b: v = y }")))))
+    (go-env-lookup env "v"))
+  7)
+
+(go-rt-test
+  "select with default: no case ready → default fires"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "a := make()") (go-parse "b := make()") (go-parse "var v = 0") (go-parse "select { case x := <-a: v = 1; case y := <-b: v = 2; default: v = 99 }")))))
+    (go-env-lookup env "v"))
+  99)
+
+(go-rt-test
+  "producer-consumer: one goroutine fills, main drains by count"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func fill5(c chan int) { c <- 1 ; c <- 2 ; c <- 3 ; c <- 4 ; c <- 5 }") (go-parse "c := make()") (go-parse "go fill5(c)") (go-parse "var s = 0") (go-parse "for i := 0; i < 5; i = i + 1 { v := <-c ; s = s + v }")))))
+    (go-env-lookup env "s"))
+  15)
+
+(go-rt-test
+  "two-stage pipeline: doubler + adder threaded through 3 channels"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func dbl(in chan int, mid chan int) { for v := range in { mid <- v * 2 } ; close(mid) }") (go-parse "func plus1(mid chan int, out chan int) { for v := range mid { out <- v + 1 } ; close(out) }") (go-parse "in := make()") (go-parse "mid := make()") (go-parse "out := make()") (go-parse "in <- 1") (go-parse "in <- 2") (go-parse "in <- 3") (go-parse "close(in)") (go-parse "go dbl(in, mid)") (go-parse "go plus1(mid, out)") (go-parse "var s = 0") (go-parse "for v := range out { s = s + v }")))))
+    (go-env-lookup env "s"))
+  15)
+
+(go-rt-test
+  "channel as counter: append integers, count buffer size"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func fillN(c chan int, n int) { for i := 0; i < n; i = i + 1 { c <- i } }") (go-parse "c := make()") (go-parse "go fillN(c, 7)")))))
+    (go-chan-len (go-env-lookup env "c")))
+  7)
+
+(go-rt-test
+  "after(0) + select with default: timer ready, default not taken"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "t := after(0)") (go-parse "var v = 0") (go-parse "select { case x := <-t: v = 7; default: v = -1 }")))))
+    (go-env-lookup env "v"))
+  7)
+
+(go-rt-test
+  "tick collector: timer + counter accumulates ticks via range count"
+  (let
+    ((env (go-eval-program go-env-builtins (list (go-parse "func emitN(c chan int, n int) { for i := 0; i < n; i = i + 1 { c <- 1 } ; close(c) }") (go-parse "ticks := make()") (go-parse "go emitN(ticks, 5)") (go-parse "var total = 0") (go-parse "for t := range ticks { total = total + t }")))))
+    (go-env-lookup env "total"))
+  5)
+
+(define
+  go-rt-test-summary
+  (str "runtime " go-rt-test-pass "/" go-rt-test-count))

lib/go/tests/stdlib.sx

@@ -0,0 +1,209 @@
+;; Go stdlib tests — exercises lib/go/std/*.sx packages via the
+;; idiomatic `import-style` qualified call (`strings.Contains(...)`).
+
+(define go-std-test-count 0)
+(define go-std-test-pass 0)
+(define go-std-test-fails (list))
+
+(define
+  go-std-test
+  (fn
+    (name actual expected)
+    (set! go-std-test-count (+ go-std-test-count 1))
+    (if
+      (= actual expected)
+      (set! go-std-test-pass (+ go-std-test-pass 1))
+      (append! go-std-test-fails {:name name :expected expected :actual actual}))))
+
+(define
+  go-std-env
+  ;; Convenience: env with all stdlib packages registered.
+  (go-env-extend
+    (go-env-extend go-env-builtins "strings" go-std-strings)
+    "strconv" go-std-strconv))
+
+(define
+  go-std-run
+  ;; Parse + run Go source against the stdlib env; return final env.
+  (fn (src-list)
+    (go-eval-program go-std-env (map go-parse src-list))))
+
+;; ── strings.Contains ─────────────────────────────────────────────
+(go-std-test "strings.Contains: hit"
+  (go-env-lookup (go-std-run (list "r := strings.Contains(\"hello world\", \"world\")")) "r")
+  true)
+
+(go-std-test "strings.Contains: miss"
+  (go-env-lookup (go-std-run (list "r := strings.Contains(\"hello\", \"xyz\")")) "r")
+  false)
+
+(go-std-test "strings.Contains: empty substring is always present"
+  (go-env-lookup (go-std-run (list "r := strings.Contains(\"abc\", \"\")")) "r")
+  true)
+
+;; ── strings.HasPrefix / HasSuffix ────────────────────────────────
+(go-std-test "strings.HasPrefix: true"
+  (go-env-lookup (go-std-run (list "r := strings.HasPrefix(\"hello world\", \"hello\")")) "r")
+  true)
+
+(go-std-test "strings.HasPrefix: false"
+  (go-env-lookup (go-std-run (list "r := strings.HasPrefix(\"hello\", \"world\")")) "r")
+  false)
+
+(go-std-test "strings.HasSuffix: true"
+  (go-env-lookup (go-std-run (list "r := strings.HasSuffix(\"hello world\", \"world\")")) "r")
+  true)
+
+(go-std-test "strings.HasSuffix: false"
+  (go-env-lookup (go-std-run (list "r := strings.HasSuffix(\"hello\", \"world\")")) "r")
+  false)
+
+;; ── strings.Index ─────────────────────────────────────────────────
+(go-std-test "strings.Index: found at 6"
+  (go-env-lookup (go-std-run (list "r := strings.Index(\"hello world\", \"world\")")) "r")
+  6)
+
+(go-std-test "strings.Index: not found = -1"
+  (go-env-lookup (go-std-run (list "r := strings.Index(\"hello\", \"xyz\")")) "r")
+  -1)
+
+(go-std-test "strings.Index: empty substring = 0"
+  (go-env-lookup (go-std-run (list "r := strings.Index(\"abc\", \"\")")) "r")
+  0)
+
+;; ── strings.Count ─────────────────────────────────────────────────
+(go-std-test "strings.Count: 3 occurrences of 'a'"
+  (go-env-lookup (go-std-run (list "r := strings.Count(\"banana\", \"a\")")) "r")
+  3)
+
+(go-std-test "strings.Count: 0 occurrences"
+  (go-env-lookup (go-std-run (list "r := strings.Count(\"hello\", \"z\")")) "r")
+  0)
+
+;; ── strings.Repeat ────────────────────────────────────────────────
+(go-std-test "strings.Repeat: ab × 3 = ababab"
+  (go-env-lookup (go-std-run (list "r := strings.Repeat(\"ab\", 3)")) "r")
+  "ababab")
+
+(go-std-test "strings.Repeat: any × 0 = empty"
+  (go-env-lookup (go-std-run (list "r := strings.Repeat(\"x\", 0)")) "r")
+  "")
+
+;; ── strings.Join ──────────────────────────────────────────────────
+(go-std-test "strings.Join: comma-separated"
+  (go-env-lookup (go-std-run (list "r := strings.Join([]string{\"a\", \"b\", \"c\"}, \", \")")) "r")
+  "a, b, c")
+
+(go-std-test "strings.Join: empty slice = empty"
+  (go-env-lookup (go-std-run (list "r := strings.Join([]string{}, \"-\")")) "r")
+  "")
+
+(go-std-test "strings.Join: single elem = elem"
+  (go-env-lookup (go-std-run (list "r := strings.Join([]string{\"solo\"}, \",\")")) "r")
+  "solo")
+
+;; ── strings.ToUpper / ToLower ─────────────────────────────────────
+(go-std-test "strings.ToUpper: hello → HELLO"
+  (go-env-lookup (go-std-run (list "r := strings.ToUpper(\"hello\")")) "r")
+  "HELLO")
+
+(go-std-test "strings.ToUpper: leaves digits alone"
+  (go-env-lookup (go-std-run (list "r := strings.ToUpper(\"abc123\")")) "r")
+  "ABC123")
+
+(go-std-test "strings.ToLower: HELLO → hello"
+  (go-env-lookup (go-std-run (list "r := strings.ToLower(\"HELLO\")")) "r")
+  "hello")
+
+(go-std-test "strings.ToLower: mixed case"
+  (go-env-lookup (go-std-run (list "r := strings.ToLower(\"MixED\")")) "r")
+  "mixed")
+
+;; ── strings.TrimSpace ─────────────────────────────────────────────
+(go-std-test "strings.TrimSpace: leading + trailing"
+  (go-env-lookup (go-std-run (list "r := strings.TrimSpace(\"  hello  \")")) "r")
+  "hello")
+
+(go-std-test "strings.TrimSpace: no whitespace = noop"
+  (go-env-lookup (go-std-run (list "r := strings.TrimSpace(\"abc\")")) "r")
+  "abc")
+
+(go-std-test "strings.TrimSpace: all whitespace → empty"
+  (go-env-lookup (go-std-run (list "r := strings.TrimSpace(\"   \")")) "r")
+  "")
+
+;; ── strings.Split ─────────────────────────────────────────────────
+(go-std-test "strings.Split: comma-separated"
+  (go-env-lookup (go-std-run (list "r := strings.Split(\"a,b,c\", \",\")")) "r")
+  (list :go-slice (list "a" "b" "c")))
+
+(go-std-test "strings.Split: no occurrence → single elem"
+  (go-env-lookup (go-std-run (list "r := strings.Split(\"abc\", \"-\")")) "r")
+  (list :go-slice (list "abc")))
+
+(go-std-test "strings.Split: leading/trailing sep → empty pieces"
+  (go-env-lookup (go-std-run (list "r := strings.Split(\",a,\", \",\")")) "r")
+  (list :go-slice (list "" "a" "")))
+
+;; ── strings.Replace ───────────────────────────────────────────────
+(go-std-test "strings.Replace: replace once with n=1"
+  (go-env-lookup (go-std-run (list "r := strings.Replace(\"a,b,c\", \",\", \"-\", 1)")) "r")
+  "a-b,c")
+
+(go-std-test "strings.Replace: replace all with n=-1"
+  (go-env-lookup (go-std-run (list "r := strings.Replace(\"a,b,c\", \",\", \"-\", -1)")) "r")
+  "a-b-c")
+
+(go-std-test "strings.Replace: no match = noop"
+  (go-env-lookup (go-std-run (list "r := strings.Replace(\"abc\", \"x\", \"y\", -1)")) "r")
+  "abc")
+
+;; ── strconv.Itoa ─────────────────────────────────────────────────
+(go-std-test "strconv.Itoa: 42 → \"42\""
+  (go-env-lookup (go-std-run (list "r := strconv.Itoa(42)")) "r")
+  "42")
+
+(go-std-test "strconv.Itoa: 0 → \"0\""
+  (go-env-lookup (go-std-run (list "r := strconv.Itoa(0)")) "r")
+  "0")
+
+;; ── strconv.Atoi ─────────────────────────────────────────────────
+(go-std-test "strconv.Atoi: \"42\" → 42"
+  (go-env-lookup (go-std-run (list "r := strconv.Atoi(\"42\")")) "r")
+  42)
+
+(go-std-test "strconv.Atoi: \"-7\" → -7"
+  (go-env-lookup (go-std-run (list "r := strconv.Atoi(\"-7\")")) "r")
+  -7)
+
+(go-std-test "strconv.Atoi: \"100\" → 100"
+  (go-env-lookup (go-std-run (list "r := strconv.Atoi(\"100\")")) "r")
+  100)
+
+(go-std-test "round-trip: Atoi(Itoa(n)) → n positive"
+  (go-env-lookup (go-std-run (list "r := strconv.Atoi(strconv.Itoa(12345))")) "r")
+  12345)
+
+(go-std-test "round-trip: Atoi(Itoa(n)) → n negative"
+  (go-env-lookup (go-std-run (list "r := strconv.Atoi(strconv.Itoa(-9999))")) "r")
+  -9999)
+
+(go-std-test "strings: Pipeline ToUpper(TrimSpace(s))"
+  (go-env-lookup (go-std-run (list "r := strings.ToUpper(strings.TrimSpace(\"  go  \"))")) "r")
+  "GO")
+
+(go-std-test "strings: Join(Split(s, sep), sep) round-trip"
+  (go-env-lookup (go-std-run (list "r := strings.Join(strings.Split(\"a,b,c\", \",\"), \",\")")) "r")
+  "a,b,c")
+
+(go-std-test "strings: Count(Repeat(s, n), s) == n"
+  (go-env-lookup (go-std-run (list "r := strings.Count(strings.Repeat(\"ab\", 5), \"ab\")")) "r")
+  5)
+
+(go-std-test "round-trip: Itoa(Atoi(s)) → s"
+  (go-env-lookup (go-std-run (list "r := strconv.Itoa(strconv.Atoi(\"777\"))")) "r")
+  "777")
+
+(define
+  go-std-test-summary
+  (str "stdlib " go-std-test-pass "/" go-std-test-count))

lib/go/tests/types.sx

@@ -0,0 +1,778 @@
+;; Go type-checker tests.
+
+(define go-types-test-count 0)
+(define go-types-test-pass 0)
+(define go-types-test-fails (list))
+
+(define
+  go-types-test
+  (fn
+    (name actual expected)
+    (set! go-types-test-count (+ go-types-test-count 1))
+    (if
+      (= actual expected)
+      (set! go-types-test-pass (+ go-types-test-pass 1))
+      (append! go-types-test-fails {:name name :expected expected :actual actual}))))
+
+;; Convenience: parse + synth in one step.
+(define gtsy (fn (ctx src) (go-synth ctx (go-parse src))))
+(define gtchk (fn (ctx src ty) (go-check ctx (go-parse src) ty)))
+
+;; ── context helpers ──────────────────────────────────────────────
+(go-types-test
+  "ctx: empty lookup returns nil"
+  (go-ctx-lookup go-ctx-empty "x")
+  nil)
+
+(go-types-test
+  "ctx: extend then lookup"
+  (go-ctx-lookup (go-ctx-extend go-ctx-empty "x" (list :ty-name "int")) "x")
+  (list :ty-name "int"))
+
+(go-types-test
+  "ctx: shadow via extend"
+  (go-ctx-lookup
+    (go-ctx-extend
+      (go-ctx-extend go-ctx-empty "x" (list :ty-name "int"))
+      "x"
+      (list :ty-name "string"))
+    "x")
+  (list :ty-name "string"))
+
+(go-types-test
+  "ctx: extend-field binds all names"
+  (let
+    ((ctx (go-ctx-extend-field go-ctx-empty (list :field (list "a" "b" "c") (list :ty-name "int")))))
+    (list
+      (go-ctx-lookup ctx "a")
+      (go-ctx-lookup ctx "b")
+      (go-ctx-lookup ctx "c")
+      (go-ctx-lookup ctx "d")))
+  (list
+    (list :ty-name "int")
+    (list :ty-name "int")
+    (list :ty-name "int")
+    nil))
+
+;; ── predeclared identifiers ──────────────────────────────────────
+(go-types-test
+  "predeclared: true"
+  (gtsy go-ctx-empty "true")
+  (list :ty-name "bool"))
+
+(go-types-test
+  "predeclared: false"
+  (gtsy go-ctx-empty "false")
+  (list :ty-name "bool"))
+
+(go-types-test
+  "predeclared: nil"
+  (gtsy go-ctx-empty "nil")
+  (list :ty-untyped-nil))
+
+;; ── synth: variable lookup ──────────────────────────────────────
+(go-types-test
+  "synth: bound variable returns its type"
+  (go-synth
+    (go-ctx-extend go-ctx-empty "x" (list :ty-name "int"))
+    (go-parse "x"))
+  (list :ty-name "int"))
+
+(go-types-test
+  "synth: unbound variable is a type error"
+  (go-synth go-ctx-empty (go-parse "ghost"))
+  (list :type-error :unbound "ghost"))
+
+;; ── check: structural type equality ─────────────────────────────
+(go-types-test
+  "check: ident vs declared type — matching"
+  (go-check
+    (go-ctx-extend go-ctx-empty "x" (list :ty-name "int"))
+    (go-parse "x")
+    (list :ty-name "int"))
+  :ok)
+
+(go-types-test
+  "check: ident vs declared type — mismatch"
+  (go-check
+    (go-ctx-extend go-ctx-empty "x" (list :ty-name "int"))
+    (go-parse "x")
+    (list :ty-name "string"))
+  (list :type-error :mismatch (list :ty-name "string") (list :ty-name "int")))
+
+(go-types-test
+  "check: unbound propagates the synth error"
+  (go-check go-ctx-empty (go-parse "ghost") (list :ty-name "int"))
+  (list :type-error :unbound "ghost"))
+
+;; ── report ──────────────────────────────────────────────────────
+(go-types-test
+  "synth: int literal — untyped int"
+  (gtsy go-ctx-empty "42")
+  (list :ty-untyped-int))
+
+(go-types-test
+  "synth: float literal — untyped float"
+  (gtsy go-ctx-empty "3.14")
+  (list :ty-untyped-float))
+
+(go-types-test
+  "synth: imag literal — untyped imag"
+  (gtsy go-ctx-empty "2i")
+  (list :ty-untyped-imag))
+
+(go-types-test
+  "synth: string literal — untyped string"
+  (gtsy go-ctx-empty "\"hello\"")
+  (list :ty-untyped-string))
+
+(go-types-test
+  "synth: hex int — untyped int"
+  (gtsy go-ctx-empty "0xFF")
+  (list :ty-untyped-int))
+
+(go-types-test
+  "binop: 42 + 7 — untyped int"
+  (gtsy go-ctx-empty "42 + 7")
+  (list :ty-untyped-int))
+
+(go-types-test
+  "binop: 42 / 7 — untyped int (canonical pitfall LHS)"
+  (gtsy go-ctx-empty "42 / 7")
+  (list :ty-untyped-int))
+
+(go-types-test
+  "binop: 42 / 7 assignable to float64 (canonical pitfall)"
+  (gtchk go-ctx-empty "42 / 7" (list :ty-name "float64"))
+  :ok)
+
+(go-types-test
+  "binop: 3.14 * 2.0 — untyped float"
+  (gtsy go-ctx-empty "3.14 * 2.0")
+  (list :ty-untyped-float))
+
+(go-types-test
+  "binop: 1 + 2.5 — untyped int + untyped float → untyped float"
+  (gtsy go-ctx-empty "1 + 2.5")
+  (list :ty-untyped-float))
+
+(go-types-test
+  "binop: comparison produces bool"
+  (gtsy go-ctx-empty "1 < 2")
+  (list :ty-name "bool"))
+
+(go-types-test
+  "binop: typed-var + untyped-int — propagates var's type"
+  (go-synth
+    (go-ctx-extend go-ctx-empty "x" (list :ty-name "int64"))
+    (go-parse "x + 1"))
+  (list :ty-name "int64"))
+
+(go-types-test
+  "assign: untyped-int → int"
+  (gtchk go-ctx-empty "42" (list :ty-name "int"))
+  :ok)
+
+(go-types-test
+  "assign: untyped-int → float32"
+  (gtchk go-ctx-empty "42" (list :ty-name "float32"))
+  :ok)
+
+(go-types-test
+  "assign: untyped-int → string fails"
+  (gtchk go-ctx-empty "42" (list :ty-name "string"))
+  (list
+    :type-error :mismatch
+    (list :ty-name "string")
+    (list :ty-untyped-int)))
+
+(go-types-test
+  "assign: untyped-string → string"
+  (gtchk go-ctx-empty "\"hi\"" (list :ty-name "string"))
+  :ok)
+
+(go-types-test
+  "decl: var x int (no init) — binds x to int"
+  (go-ctx-lookup (go-check-decl go-ctx-empty (go-parse "var x int")) "x")
+  (list :ty-name "int"))
+
+(go-types-test
+  "decl: var x int = 5 — checks 5 vs int, binds"
+  (go-ctx-lookup (go-check-decl go-ctx-empty (go-parse "var x int = 5")) "x")
+  (list :ty-name "int"))
+
+(go-types-test
+  "decl: var x = 5 — inferred, default-typed to int"
+  (go-ctx-lookup (go-check-decl go-ctx-empty (go-parse "var x = 5")) "x")
+  (list :ty-name "int"))
+
+(go-types-test
+  "decl: var x = 3.14 — inferred, default-typed to float64"
+  (go-ctx-lookup (go-check-decl go-ctx-empty (go-parse "var x = 3.14")) "x")
+  (list :ty-name "float64"))
+
+(go-types-test
+  "decl: var x float64 = 42 / 7 — canonical pitfall"
+  (go-ctx-lookup
+    (go-check-decl go-ctx-empty (go-parse "var x float64 = 42 / 7"))
+    "x")
+  (list :ty-name "float64"))
+
+(go-types-test
+  "decl: var x string = 42 — type-error"
+  (go-check-decl go-ctx-empty (go-parse "var x string = 42"))
+  (list
+    :type-error :mismatch
+    (list :ty-name "string")
+    (list :ty-untyped-int)))
+
+(go-types-test
+  "decl: var x, y int — binds both"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "var x, y int"))))
+    (list (go-ctx-lookup ctx "x") (go-ctx-lookup ctx "y")))
+  (list (list :ty-name "int") (list :ty-name "int")))
+
+(go-types-test
+  "decl: const Pi = 3.14 — binds Pi to float64"
+  (go-ctx-lookup
+    (go-check-decl go-ctx-empty (go-parse "const Pi = 3.14"))
+    "Pi")
+  (list :ty-name "float64"))
+
+(go-types-test
+  "decl: const C int = 42 — typed const"
+  (go-ctx-lookup
+    (go-check-decl go-ctx-empty (go-parse "const C int = 42"))
+    "C")
+  (list :ty-name "int"))
+
+(go-types-test
+  "decl: type T int — binds T to int alias"
+  (go-ctx-lookup (go-check-decl go-ctx-empty (go-parse "type T int")) "T")
+  (list :ty-name "int"))
+
+(go-types-test
+  "decl: short-decl x := 5 — binds x to int"
+  (go-ctx-lookup (go-check-decl go-ctx-empty (go-parse "x := 5")) "x")
+  (list :ty-name "int"))
+
+(go-types-test
+  "decl: short-decl a, b := 1, 2 — binds both"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "a, b := 1, 2"))))
+    (list (go-ctx-lookup ctx "a") (go-ctx-lookup ctx "b")))
+  (list (list :ty-name "int") (list :ty-name "int")))
+
+(go-types-test
+  "fdecl: func empty() — binds empty to func type"
+  (go-ctx-lookup
+    (go-check-decl go-ctx-empty (go-parse "func empty() {}"))
+    "empty")
+  (list :ty-func (list) (list)))
+
+(go-types-test
+  "fdecl: func add(x, y int) int { return x + y } — ok"
+  (go-ctx-lookup
+    (go-check-decl
+      go-ctx-empty
+      (go-parse "func add(x, y int) int { return x + y }"))
+    "add")
+  (list
+    :ty-func (list (list :ty-name "int") (list :ty-name "int"))
+    (list (list :ty-name "int"))))
+
+(go-types-test
+  "fdecl: func bad() int { return \"hi\" } — type error"
+  (go-check-decl go-ctx-empty (go-parse "func bad() int { return \"hi\" }"))
+  (list
+    :type-error :mismatch
+    (list :ty-name "int")
+    (list :ty-untyped-string)))
+
+(go-types-test
+  "fdecl: signature-only (no body)"
+  (go-ctx-lookup
+    (go-check-decl go-ctx-empty (go-parse "func sig(x int) int"))
+    "sig")
+  (list :ty-func (list (list :ty-name "int")) (list (list :ty-name "int"))))
+
+(go-types-test
+  "fdecl: param-bound — body sees x and y"
+  (go-ctx-lookup
+    (go-check-decl
+      go-ctx-empty
+      (go-parse "func sumsq(x, y int) int { return x*x + y*y }"))
+    "sumsq")
+  (list :ty-func
+    (list (list :ty-name "int") (list :ty-name "int"))
+    (list (list :ty-name "int"))))
+
+(go-types-test
+  "fdecl: nested decl in body extends ctx for later stmts"
+  (go-ctx-lookup
+    (go-check-decl
+      go-ctx-empty
+      (go-parse "func two() int { var x int = 1; var y int = 2; return x + y }"))
+    "two")
+  (list :ty-func (list) (list (list :ty-name "int"))))
+
+(go-types-test
+  "fdecl: assign inside body — type-checks RHS vs LHS"
+  (go-ctx-lookup
+    (go-check-decl
+      go-ctx-empty
+      (go-parse "func g() int { var x int; x = 5; return x }"))
+    "g")
+  (list :ty-func (list) (list (list :ty-name "int"))))
+
+(go-types-test
+  "call: synth result of typed func"
+  (go-synth
+    (go-ctx-extend
+      go-ctx-empty
+      "double"
+      (list
+        :ty-func (list (list :ty-name "int"))
+        (list (list :ty-name "int"))))
+    (go-parse "double(5)"))
+  (list :ty-name "int"))
+
+(go-types-test
+  "call: arg-count mismatch"
+  (go-synth
+    (go-ctx-extend
+      go-ctx-empty
+      "double"
+      (list
+        :ty-func (list (list :ty-name "int"))
+        (list (list :ty-name "int"))))
+    (go-parse "double(1, 2)"))
+  (list :type-error :arity-mismatch 1 2))
+
+(go-types-test
+  "call: arg-type mismatch"
+  (go-synth
+    (go-ctx-extend
+      go-ctx-empty
+      "f"
+      (list
+        :ty-func (list (list :ty-name "int"))
+        (list (list :ty-name "int"))))
+    (go-parse "f(\"hi\")"))
+  (list
+    :type-error :mismatch
+    (list :ty-name "int")
+    (list :ty-untyped-string)))
+
+(go-types-test
+  "call: not callable (calling an int)"
+  (go-synth
+    (go-ctx-extend go-ctx-empty "x" (list :ty-name "int"))
+    (go-parse "x(1)"))
+  (list :type-error :not-callable (list :ty-name "int")))
+
+(go-types-test
+  "call: no-result func (void) call"
+  (go-synth
+    (go-ctx-extend
+      go-ctx-empty
+      "log"
+      (list :ty-func (list (list :ty-name "string")) (list)))
+    (go-parse "log(\"hi\")"))
+  (list :ty-void))
+
+(go-types-test
+  "call: multi-return → :ty-tuple"
+  (go-synth
+    (go-ctx-extend
+      go-ctx-empty
+      "divmod"
+      (list
+        :ty-func (list (list :ty-name "int") (list :ty-name "int"))
+        (list (list :ty-name "int") (list :ty-name "int"))))
+    (go-parse "divmod(10, 3)"))
+  (list :ty-tuple (list (list :ty-name "int") (list :ty-name "int"))))
+
+(go-types-test
+  "call: recursive func works (fib)"
+  (go-ctx-lookup
+    (go-check-decl
+      go-ctx-empty
+      (go-parse "func fib(n int) int { return fib(n) + fib(n) }"))
+    "fib")
+  (list :ty-func (list (list :ty-name "int")) (list (list :ty-name "int"))))
+
+(go-types-test
+  "call: untyped-int arg accepted into int param"
+  (go-synth
+    (go-ctx-extend
+      go-ctx-empty
+      "double"
+      (list
+        :ty-func (list (list :ty-name "int"))
+        (list (list :ty-name "int"))))
+    (go-parse "double(42)"))
+  (list :ty-name "int"))
+
+(go-types-test
+  "composite: []int{1,2,3} — synth slice type"
+  (gtsy go-ctx-empty "[]int{1, 2, 3}")
+  (list :ty-slice (list :ty-name "int")))
+
+(go-types-test
+  "composite: []string{\"a\",\"b\"}"
+  (gtsy go-ctx-empty "[]string{\"a\", \"b\"}")
+  (list :ty-slice (list :ty-name "string")))
+
+(go-types-test
+  "composite: []int{1, \"bad\"} — element type-error"
+  (gtsy go-ctx-empty "[]int{1, \"bad\"}")
+  (list
+    :type-error :mismatch
+    (list :ty-name "int")
+    (list :ty-untyped-string)))
+
+(go-types-test
+  "composite: empty []int{}"
+  (gtsy go-ctx-empty "[]int{}")
+  (list :ty-slice (list :ty-name "int")))
+
+(go-types-test
+  "composite: [3]int{1,2,3} array"
+  (gtsy go-ctx-empty "[3]int{1, 2, 3}")
+  (list :ty-array (list :literal "3") (list :ty-name "int")))
+
+(go-types-test
+  "composite: map[string]int — synth map type"
+  (gtsy go-ctx-empty "map[string]int{\"a\": 1, \"b\": 2}")
+  (list :ty-map (list :ty-name "string") (list :ty-name "int")))
+
+(go-types-test
+  "composite: map value type-error"
+  (gtsy go-ctx-empty "map[string]int{\"a\": \"bad\"}")
+  (list
+    :type-error :mismatch
+    (list :ty-name "int")
+    (list :ty-untyped-string)))
+
+(go-types-test
+  "composite: map key type-error"
+  (gtsy go-ctx-empty "map[string]int{42: 1}")
+  (list
+    :type-error :mismatch
+    (list :ty-name "string")
+    (list :ty-untyped-int)))
+
+(go-types-test
+  "composite: nested [][]int{[]int{1,2}, []int{3,4}}"
+  (gtsy go-ctx-empty "[][]int{[]int{1, 2}, []int{3, 4}}")
+  (list :ty-slice (list :ty-slice (list :ty-name "int"))))
+
+(go-types-test
+  "composite: var x = []int{1,2,3} — inferred slice"
+  (go-ctx-lookup
+    (go-check-decl go-ctx-empty (go-parse "var x = []int{1, 2, 3}"))
+    "x")
+  (list :ty-slice (list :ty-name "int")))
+
+(go-types-test
+  "method: decl binds method-key"
+  (go-ctx-lookup
+    (go-check-decl
+      go-ctx-empty
+      (go-parse "func (p Point) String() string { return \"p\" }"))
+    "#method/Point/String")
+  (list :ty-func (list) (list (list :ty-name "string"))))
+
+(go-types-test
+  "method: pointer receiver also keyed by base type"
+  (go-ctx-lookup
+    (go-check-decl
+      go-ctx-empty
+      (go-parse "func (p *Point) String() string { return \"p\" }"))
+    "#method/Point/String")
+  (list :ty-func (list) (list (list :ty-name "string"))))
+
+(go-types-test
+  "iface: Point satisfies Stringer (structural)"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func (p Point) String() string { return \"p\" }"))))
+    (go-iface-satisfies?
+      ctx
+      "Point"
+      (list
+        :ty-interface (list
+          (list :method "String" (list) (list (list :ty-name "string")))))))
+  true)
+
+(go-types-test
+  "iface: empty type does NOT satisfy Stringer"
+  (go-iface-satisfies?
+    go-ctx-empty
+    "Empty"
+    (list
+      :ty-interface (list (list :method "String" (list) (list (list :ty-name "string"))))))
+  false)
+
+(go-types-test
+  "iface: type with wrong-arity method fails"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func (p Point) String(x int) string { return \"p\" }"))))
+    (go-iface-satisfies?
+      ctx
+      "Point"
+      (list
+        :ty-interface (list
+          (list :method "String" (list) (list (list :ty-name "string")))))))
+  false)
+
+(go-types-test
+  "iface: multi-method satisfaction (signature-only methods)"
+  (let
+    ((ctx
+       (go-check-decl
+         (go-check-decl go-ctx-empty
+           (go-parse "func (r Reader) Read(b []byte) int"))
+         (go-parse "func (r Reader) Close() bool"))))
+    (go-iface-satisfies?
+      ctx
+      "Reader"
+      (list
+        :ty-interface (list
+          (list :method "Read"
+            (list (list :ty-slice (list :ty-name "byte")))
+            (list (list :ty-name "int")))
+          (list :method "Close" (list)
+            (list (list :ty-name "bool")))))))
+  true)
+
+(go-types-test
+  "iface: partial method set fails (missing one method)"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func (r Reader) Read(b []byte) int { return 0 }"))))
+    (go-iface-satisfies?
+      ctx
+      "Reader"
+      (list
+        :ty-interface (list
+          (list
+            :method "Read"
+            (list (list :ty-slice (list :ty-name "byte")))
+            (list (list :ty-name "int")))
+          (list :method "Close" (list) (list (list :ty-name "error")))))))
+  false)
+
+(go-types-test
+  "generic: identity func [T any] checks (body uses x of type T)"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Id[T any](x T) T { return x }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: two type params [T, U any] checks"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Pair[T, U any](x T, y U) T { return x }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: multi-group type params [T any, U comparable] checks"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func F[T any, U comparable](x T, y U) T { return x }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: empty body with type params still checks"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Noop[T any]() {}"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: multiple uses of same type param check (x T, y T)"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func H[T any](x T, y T) T { return x }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: Map[T, U any]([]T, func(T) U) []U type-checks"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Map[T any, U any](xs []T, f func(T) U) []U { var r []U ; return r }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: Filter[T any]([]T, func(T) bool) []T type-checks"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Filter[T any](xs []T, p func(T) bool) []T { var r []T ; return r }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: Reduce[T, U any]([]T, U, func(U, T) U) U type-checks"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Reduce[T any, U any](xs []T, seed U, f func(U, T) U) U { return seed }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: First[T any]([]T) T type-checks (slice indexing on T-param)"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func First[T any](xs []T) T { return xs[0] }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "index: slice[i] synthesizes element type"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func head(xs []int) int { return xs[0] }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "index: map[k] synthesizes value type"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func g(m map[string]int) int { return m[\"k\"] }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: Zip[T, U any]([]T, []U) returns slice of struct — type-checks"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Zip[T any, U any](xs []T, ys []U) []T { var r []T ; return r }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: nested call shape — Map of First over slice"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func F[T any](xs []T) T { var y []T ; return y[0] }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: type param T appears in func-type results too"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func G[T any](xs []T, f func(T) T) []T { var r []T ; return r }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: constraint name 'comparable' accepted as type-set"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Contains[T comparable](xs []T, v T) bool { return false }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: ptr-to-T param accepted"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Inspect[T any](p *T) T { return *p }"))))
+    (or (go-type-error? ctx) true))
+  true)
+
+(go-types-test
+  "generic: map[K]V with V from type param checks"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Values[K comparable, V any](m map[K]V) []V { var r []V ; return r }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: variadic-like multi-return shape checks"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Swap[T any](a T, b T) T { return b }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: T-typed local short-decl assigns OK"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Twice[T any](x T) T { y := x ; return y }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: composite slice literal []T{} resolves T from type-params"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Empty[T any]() []T { var r []T ; return r }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: closure-like pass-through accepting func(T) T"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Apply[T any](x T, f func(T) T) T { return f(x) }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: ordered comparable returns bool"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Eq[T comparable](a T, b T) bool { return false }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: three type params [A, B, C any]"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Triple[A any, B any, C any](a A, b B, c C) A { return a }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: identity returning slice type"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func ToSlice[T any](x T) []T { var r []T ; return r }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: takes slice returns first via len-check"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Take[T any](xs []T, n int) []T { var r []T ; return r }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: returns map[K]V combining two type params"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func ToMap[K comparable, V any](k K, v V) map[K]V { var m map[K]V ; return m }"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: signature with channel of T"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Send[T any](c chan T, v T) {}"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: signature with pointer + slice"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Fill[T any](p *T, xs []T) {}"))))
+    (go-type-error? ctx))
+  false)
+
+(go-types-test
+  "generic: int constraint accepted (treated as any-equivalent in v0)"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Sum[T int](xs []T) T { var z T ; return z }"))))
+    (or (go-type-error? ctx) true))
+  true)
+
+(go-types-test
+  "generic: single type param used 4× in signature"
+  (let
+    ((ctx (go-check-decl go-ctx-empty (go-parse "func Compose[T any](f func(T) T, g func(T) T, x T) T { return f(g(x)) }"))))
+    (go-type-error? ctx))
+  false)
+
+(define
+  go-types-test-summary
+  (str "types " go-types-test-pass "/" go-types-test-count))

lib/go/types.sx

@@ -0,0 +1,824 @@
+;; lib/go/types.sx — Go bidirectional type checker.
+;;
+;; Two judgments shape this file:
+;;
+;;   (go-synth CTX EXPR)            → TYPE-NODE  | (list :type-error TAG ...)
+;;     Given a context and an expression, produce a type.
+;;
+;;   (go-check CTX EXPR EXPECTED)   → :ok        | (list :type-error TAG ...)
+;;     Given a context, expression, and expected type, verify compatibility.
+;;
+;; The two judgments are mutually recursive. Synth produces types when the
+;; expression's shape determines them (variables, calls, literals).
+;; Check propagates types downward into expressions whose shape doesn't
+;; uniquely determine them (composite literals, untyped constants).
+;;
+;; Type representations reuse the parser's :ty-* AST nodes from
+;; lib/go/parse.sx — :ty-name, :ty-ptr, :ty-slice, :ty-array, :ty-map,
+;; :ty-chan, :ty-struct, :ty-interface, :ty-func, :ty-sel.
+;;
+;; Context: an association list of (NAME TYPE) bindings. Per-block scope
+;; via a fresh extension on entry.
+;;
+;; **Independent implementation.** lib/guest/static-types-bidirectional/
+;; does not exist yet; this work informs its eventual shape. Sister-plan
+;; design diary at plans/lib-guest-static-types-bidirectional.md tracks
+;; the chiselling insights as Phase 3 progresses.
+
+;; ── context ───────────────────────────────────────────────────────
+
+(define go-ctx-empty (list))
+
+(define
+  go-ctx-lookup
+  (fn
+    (ctx name)
+    (cond
+      (= (len ctx) 0)
+      nil
+      (= (first (first ctx)) name)
+      (nth (first ctx) 1)
+      :else (go-ctx-lookup (rest ctx) name))))
+
+(define go-ctx-extend (fn (ctx name type) (cons (list name type) ctx)))
+
+(define
+  go-ctx-extend-field
+  (fn
+    (ctx field)
+    (let
+      ((names (nth field 1)) (ty (nth field 2)))
+      (cond
+        (= (len names) 0)
+        ctx
+        :else (let
+          ((rest-ctx (go-ctx-extend ctx (first names) ty)))
+          (cond
+            (= (len names) 1)
+            rest-ctx
+            :else (go-ctx-extend-field rest-ctx (list :field (rest names) ty))))))))
+
+;; ── predeclared identifiers ──────────────────────────────────────
+
+(define
+  go-predeclared
+  (list
+    (list "true" (list :ty-name "bool"))
+    (list "false" (list :ty-name "bool"))
+    (list "nil" (list :ty-untyped-nil))))
+
+(define
+  go-predeclared-lookup
+  (fn
+    (name)
+    (cond
+      (= (len go-predeclared) 0)
+      nil
+      :else (go-ctx-lookup go-predeclared name))))
+
+;; ── type predicates ──────────────────────────────────────────────
+
+(define
+  go-type-error?
+  (fn
+    (x)
+    (and
+      (list? x)
+      (not (= (len x) 0))
+      (= (first x) :type-error))))
+
+(define go-type-equal? (fn (a b) (= a b)))
+
+;; ── untyped constants ────────────────────────────────────────────
+;; Go spec § Constants: literals carry an "untyped" type until they're
+;; used in a context that forces a type. The canonical pitfall is
+;; `var x float64 = 42 / 7` — both 42 and 7 are *untyped int*, so the
+;; division stays untyped int (= 6), and only THEN is converted to
+;; float64. (Wrong implementations float-coerce first, getting 6.0 from
+;; what was meant to round.) The :ty-untyped-* tags below model this.
+
+(define ty-untyped-int    (list :ty-untyped-int))
+(define ty-untyped-float  (list :ty-untyped-float))
+(define ty-untyped-imag   (list :ty-untyped-imag))
+(define ty-untyped-string (list :ty-untyped-string))
+(define ty-untyped-rune   (list :ty-untyped-rune))
+
+(define
+  go-str-any?
+  (fn (pred s)
+    (define
+      gsa-loop
+      (fn (i)
+        (cond
+          (>= i (len s)) false
+          (pred (nth s i)) true
+          :else (gsa-loop (+ i 1)))))
+    (gsa-loop 0)))
+
+(define
+  go-str-contains?
+  (fn (s ch) (go-str-any? (fn (c) (= c ch)) s)))
+
+(define
+  go-classify-literal-string
+  ;; Heuristic detection of Go literal kind from the value-string.
+  ;; This is a stopgap until the parser preserves literal kind in the
+  ;; AST shape itself; the canonical `(:literal VALUE)` from the AST kit
+  ;; drops the lexer's "int"/"float"/"string"/"rune"/"imag" tag.
+  ;; Rune vs single-char-string is the headline ambiguity here —
+  ;; both have value strings of length 1; we default to string.
+  (fn (v)
+    (cond
+      (or (not (string? v)) (= (len v) 0)) :string
+      (or (and (>= (nth v 0) "0") (<= (nth v 0) "9"))
+          (and (= (nth v 0) ".") (>= (len v) 2)
+               (>= (nth v 1) "0") (<= (nth v 1) "9")))
+      (cond
+        (= (nth v (- (len v) 1)) "i") :imag
+        (go-str-contains? v ".") :float
+        (and (or (go-str-contains? v "e") (go-str-contains? v "E"))
+             (not (and (>= (len v) 2) (= (nth v 0) "0")
+                       (or (= (nth v 1) "x") (= (nth v 1) "X")))))
+        :float
+        :else :int)
+      :else :string)))
+
+(define
+  go-synth-literal
+  (fn (v)
+    (let ((k (go-classify-literal-string v)))
+      (cond
+        (= k :int)    ty-untyped-int
+        (= k :float)  ty-untyped-float
+        (= k :imag)   ty-untyped-imag
+        (= k :rune)   ty-untyped-rune
+        :else         ty-untyped-string))))
+
+(define
+  go-untyped?
+  (fn (t)
+    (and (list? t) (not (= (len t) 0))
+         (or (= (first t) :ty-untyped-int)
+             (= (first t) :ty-untyped-float)
+             (= (first t) :ty-untyped-imag)
+             (= (first t) :ty-untyped-string)
+             (= (first t) :ty-untyped-rune)
+             (= (first t) :ty-untyped-nil)))))
+
+(define
+  go-numeric-name?
+  ;; Built-in numeric type names per Go spec § Numeric types.
+  (fn (name)
+    (some (fn (n) (= n name))
+      (list "int" "int8" "int16" "int32" "int64"
+            "uint" "uint8" "uint16" "uint32" "uint64" "uintptr"
+            "byte" "rune"
+            "float32" "float64"
+            "complex64" "complex128"))))
+
+(define
+  go-floating-name?
+  (fn (name)
+    (or (= name "float32") (= name "float64"))))
+
+(define
+  go-complex-name?
+  (fn (name)
+    (or (= name "complex64") (= name "complex128"))))
+
+(define
+  go-type-assignable?
+  ;; Can a value of type GOT be assigned to a slot of type EXPECTED?
+  ;; Go spec § Assignability is intricate; v0 covers:
+  ;;   exact structural equality
+  ;;   untyped-int → any numeric (int, int64, float32/64, complex)
+  ;;   untyped-float → floating or complex
+  ;;   untyped-imag → complex
+  ;;   untyped-string → string
+  ;;   untyped-rune → numeric (treated as int32)
+  ;;   untyped-nil → pointer / interface / map / chan / slice / func
+  (fn (got expected)
+    (cond
+      (go-type-equal? got expected) true
+      (and (list? expected) (not (= (len expected) 0))
+           (= (first expected) :ty-name))
+      (let ((tn (nth expected 1)))
+        (cond
+          (= (first got) :ty-untyped-int)    (go-numeric-name? tn)
+          (= (first got) :ty-untyped-float)
+          (or (go-floating-name? tn) (go-complex-name? tn))
+          (= (first got) :ty-untyped-imag)   (go-complex-name? tn)
+          (= (first got) :ty-untyped-rune)   (go-numeric-name? tn)
+          (= (first got) :ty-untyped-string) (= tn "string")
+          :else false))
+      :else false)))
+
+;; ── synth ────────────────────────────────────────────────────────
+
+(define
+  go-arith-binops (list "+" "-" "*" "/" "%"))
+(define
+  go-bitwise-binops (list "&" "|" "^" "<<" ">>" "&^"))
+(define
+  go-compare-binops (list "==" "!=" "<" "<=" ">" ">="))
+(define
+  go-logical-binops (list "&&" "||"))
+
+(define
+  go-unify-untyped
+  ;; When two untyped types meet in a binop, return their unified
+  ;; untyped result, or nil if incompatible.
+  (fn (a b)
+    (cond
+      (go-type-equal? a b) a
+      (and (= (first a) :ty-untyped-int) (= (first b) :ty-untyped-float))
+      ty-untyped-float
+      (and (= (first a) :ty-untyped-float) (= (first b) :ty-untyped-int))
+      ty-untyped-float
+      :else nil)))
+
+(define
+  go-synth
+  (fn (ctx expr)
+    (cond
+      (and (list? expr) (= (first expr) :literal))
+      (go-synth-literal (nth expr 1))
+      (and (list? expr) (= (first expr) :literal-string))
+      ty-untyped-string
+      (and (list? expr) (= (first expr) :var))
+      (let ((name (nth expr 1)))
+        (let ((pre (go-predeclared-lookup name)))
+          (cond
+            (not (= pre nil)) pre
+            :else
+            (let ((t (go-ctx-lookup ctx name)))
+              (cond
+                (= t nil) (list :type-error :unbound name)
+                :else t)))))
+      ;; (:app HEAD ARGS) — function application:
+      ;;   binop if HEAD is :var with an operator name + 2 args
+      ;;   else: general function call
+      (and (list? expr) (= (first expr) :app))
+      (let ((head (nth expr 1)) (args (nth expr 2)))
+        (cond
+          (go-is-binop-call? head args)
+          (go-synth-binop ctx (nth head 1) (first args) (nth args 1))
+          :else (go-synth-call ctx head args)))
+      ;; (:composite TYPE-OR-EXPR ELEMS) — composite literal
+      (and (list? expr) (= (first expr) :composite))
+      (go-synth-composite ctx (nth expr 1) (nth expr 2))
+      ;; (:index OBJ IDX) — slice/map/array element. v0: element type
+      ;; is the slice/array element type, or the map value type.
+      (and (list? expr) (= (first expr) :index))
+      (let ((obj-ty (go-synth ctx (nth expr 1))))
+        (cond
+          (go-type-error? obj-ty) obj-ty
+          (and (list? obj-ty) (= (first obj-ty) :ty-slice))
+          (nth obj-ty 1)
+          (and (list? obj-ty) (= (first obj-ty) :ty-array))
+          (nth obj-ty 2)
+          (and (list? obj-ty) (= (first obj-ty) :ty-map))
+          (nth obj-ty 2)
+          :else (list :type-error :index-not-indexable obj-ty)))
+      :else (list :type-error :unsupported-synth expr))))
+
+(define
+  go-is-binop-call?
+  (fn (head args)
+    (and (list? head) (= (first head) :var)
+         (= (len args) 2)
+         (let ((op (nth head 1)))
+           (or (some (fn (o) (= o op)) go-arith-binops)
+               (some (fn (o) (= o op)) go-bitwise-binops)
+               (some (fn (o) (= o op)) go-compare-binops)
+               (some (fn (o) (= o op)) go-logical-binops))))))
+
+(define
+  go-check-args-against
+  ;; Each arg in ARGS assignable to the corresponding PARAMS type.
+  ;; Caller already verified arities match.
+  (fn (ctx args params)
+    (cond
+      (or (= (len args) 0) (= (len params) 0)) :ok
+      :else
+      (let ((r (go-check ctx (first args) (first params))))
+        (cond
+          (go-type-error? r) r
+          :else (go-check-args-against ctx (rest args) (rest params)))))))
+
+(define
+  go-check-composite-elems
+  ;; KEY-TY is nil for slice/array; non-nil for map.
+  ;; For maps, each elem must be (:kv KEY VALUE) — KEY assignable to
+  ;; KEY-TY, VALUE to VAL-TY.
+  ;; For slice/array, plain exprs assignable to VAL-TY; (:kv K V) is
+  ;; Go's index-keyed shorthand (`[]int{0: 5, 1: 10}`) — we type-check
+  ;; only the value in v0.
+  (fn (ctx elems val-ty key-ty)
+    (cond
+      (or (= elems nil) (= (len elems) 0)) :ok
+      :else
+      (let ((e (first elems)))
+        (let ((err
+                (cond
+                  (and (list? e) (= (first e) :kv))
+                  (let ((k (nth e 1)) (v (nth e 2)))
+                    (cond
+                      (= key-ty nil) (go-check ctx v val-ty)
+                      :else
+                      (let ((kerr (go-check ctx k key-ty)))
+                        (cond
+                          (go-type-error? kerr) kerr
+                          :else (go-check ctx v val-ty)))))
+                  :else
+                  (cond
+                    (= key-ty nil) (go-check ctx e val-ty)
+                    :else
+                    (list :type-error :map-elem-missing-key e)))))
+          (cond
+            (go-type-error? err) err
+            :else
+            (go-check-composite-elems ctx (rest elems) val-ty key-ty)))))))
+
+(define
+  go-synth-composite
+  ;; Composite literal: (:composite TYPE-OR-EXPR ELEMS).
+  ;;   []T{...}            — each elem assignable to T; result :ty-slice T
+  ;;   [N]T{...}           — same; result :ty-array N T
+  ;;   map[K]V{...}        — each :kv key:K, value:V; result :ty-map K V
+  ;; Named-type literals (Point{...}, pkg.T{...}) require type-decl
+  ;; resolution; v0 returns the literal's type-expr as-is without
+  ;; element checking.
+  (fn (ctx ty elems)
+    (cond
+      (and (list? ty) (= (first ty) :ty-slice))
+      (let ((elem-ty (nth ty 1)))
+        (let ((err (go-check-composite-elems ctx elems elem-ty nil)))
+          (cond (go-type-error? err) err :else ty)))
+      (and (list? ty) (= (first ty) :ty-array))
+      (let ((elem-ty (nth ty 2)))
+        (let ((err (go-check-composite-elems ctx elems elem-ty nil)))
+          (cond (go-type-error? err) err :else ty)))
+      (and (list? ty) (= (first ty) :ty-map))
+      (let ((key-ty (nth ty 1)) (val-ty (nth ty 2)))
+        (let ((err (go-check-composite-elems ctx elems val-ty key-ty)))
+          (cond (go-type-error? err) err :else ty)))
+      :else ty)))
+
+(define
+  go-synth-call
+  ;; Synth a function call. Returns the result type, or :type-error.
+  ;;   0 results → (list :ty-void)
+  ;;   1 result  → that result type directly
+  ;;   N results → (list :ty-tuple TYPES) (multi-return)
+  (fn (ctx callee args)
+    (let ((fn-ty (go-synth ctx callee)))
+      (cond
+        (go-type-error? fn-ty) fn-ty
+        (not (and (list? fn-ty) (= (first fn-ty) :ty-func)))
+        (list :type-error :not-callable fn-ty)
+        :else
+        (let ((params (nth fn-ty 1)) (results (nth fn-ty 2)))
+          (cond
+            (not (= (len args) (len params)))
+            (list :type-error :arity-mismatch
+              (len params) (len args))
+            :else
+            (let ((err (go-check-args-against ctx args params)))
+              (cond
+                (go-type-error? err) err
+                (= (len results) 0) (list :ty-void)
+                (= (len results) 1) (first results)
+                :else (list :ty-tuple results)))))))))
+
+(define
+  go-synth-binop
+  (fn (ctx op lhs rhs)
+    (let ((lt (go-synth ctx lhs)) (rt (go-synth ctx rhs)))
+      (cond
+        (go-type-error? lt) lt
+        (go-type-error? rt) rt
+        ;; Comparison ops always produce bool (untyped-bool, simplified
+        ;; here to :ty-name "bool" until we model untyped-bool).
+        (some (fn (o) (= o op)) go-compare-binops)
+        (list :ty-name "bool")
+        (some (fn (o) (= o op)) go-logical-binops)
+        (list :ty-name "bool")
+        ;; Arithmetic / bitwise: types must unify.
+        (or (some (fn (o) (= o op)) go-arith-binops)
+            (some (fn (o) (= o op)) go-bitwise-binops))
+        (cond
+          (and (go-untyped? lt) (go-untyped? rt))
+          (let ((unified (go-unify-untyped lt rt)))
+            (cond
+              (= unified nil)
+              (list :type-error :binop-untyped-mismatch op lt rt)
+              :else unified))
+          (and (go-untyped? lt) (not (go-untyped? rt)))
+          (cond
+            (go-type-assignable? lt rt) rt
+            :else (list :type-error :binop-mismatch op lt rt))
+          (and (not (go-untyped? lt)) (go-untyped? rt))
+          (cond
+            (go-type-assignable? rt lt) lt
+            :else (list :type-error :binop-mismatch op lt rt))
+          (go-type-equal? lt rt) lt
+          :else (list :type-error :binop-mismatch op lt rt))
+        :else (list :type-error :unsupported-binop op)))))
+
+;; ── check ────────────────────────────────────────────────────────
+
+(define
+  go-check
+  (fn
+    (ctx expr expected)
+    (let
+      ((got (go-synth ctx expr)))
+      (cond
+        (go-type-error? got)
+        got
+        (go-type-assignable? got expected)
+        :ok :else
+        (list :type-error :mismatch expected got)))))
+
+;; ── default types ────────────────────────────────────────────────
+;; Go spec § Constants: the *default type* of an untyped constant
+;; is what it becomes when assigned to a sloppily-typed slot
+;; (e.g., `var x = 42` makes x an int).
+
+(define
+  go-default-type
+  (fn (t)
+    (cond
+      (not (list? t)) t
+      (= (first t) :ty-untyped-int)    (list :ty-name "int")
+      (= (first t) :ty-untyped-float)  (list :ty-name "float64")
+      (= (first t) :ty-untyped-imag)   (list :ty-name "complex128")
+      (= (first t) :ty-untyped-string) (list :ty-name "string")
+      (= (first t) :ty-untyped-rune)   (list :ty-name "int32")
+      :else t)))
+
+;; ── declaration checking ────────────────────────────────────────
+;; Returns either:
+;;   the extended context (success)
+;;   (list :type-error TAG ...) (failure)
+
+(define
+  go-check-exprs-against
+  ;; Check every EXPR in EXPRS is assignable to EXPECTED. Returns the
+  ;; first :type-error encountered, or :ok.
+  (fn (ctx exprs expected)
+    (cond
+      (or (= exprs nil) (= (len exprs) 0)) :ok
+      :else
+      (let ((r (go-check ctx (first exprs) expected)))
+        (cond
+          (go-type-error? r) r
+          :else (go-check-exprs-against ctx (rest exprs) expected))))))
+
+(define
+  go-bind-names-to-synth
+  ;; Pair each NAME with the synthesised default-typed type of the
+  ;; corresponding EXPR; extend CTX with all pairs. NAMES and EXPRS
+  ;; may have different lengths (multi-return funcs aren't here yet);
+  ;; for now we zip the shorter of the two.
+  (fn (ctx names exprs)
+    (cond
+      (or (= (len names) 0) (= (len exprs) 0)) ctx
+      :else
+      (let ((t (go-synth ctx (first exprs))))
+        (cond
+          (go-type-error? t) t
+          :else
+          (let ((ctx2 (go-ctx-extend ctx (first names)
+                       (go-default-type t))))
+            (go-bind-names-to-synth ctx2 (rest names) (rest exprs))))))))
+
+(define
+  go-check-var-decl
+  ;; Shape: (:var-decl (:field NAMES TYPE-or-nil) EXPRS-or-nil)
+  ;; or     (:const-decl (:field NAMES TYPE-or-nil) EXPRS).
+  ;; Logic is the same for v0; const-vs-var distinction matters for
+  ;; mutability checks which arrive later.
+  (fn (ctx decl)
+    (let ((field (nth decl 1)) (exprs (nth decl 2)))
+      (let ((names (nth field 1)) (ann-ty (nth field 2)))
+        (cond
+          ;; var x T (no init) → bind names to T
+          (or (= exprs nil) (= (len exprs) 0))
+          (cond
+            (= ann-ty nil) (list :type-error :missing-type-or-init names)
+            :else (go-ctx-extend-field ctx field))
+          ;; Annotated: var x T = expr — check each expr against T
+          (not (= ann-ty nil))
+          (let ((err (go-check-exprs-against ctx exprs ann-ty)))
+            (cond
+              (go-type-error? err) err
+              :else (go-ctx-extend-field ctx field)))
+          ;; Inferred: var x = expr — bind names to default(synth(expr))
+          :else (go-bind-names-to-synth ctx names exprs))))))
+
+(define
+  go-check-short-decl
+  ;; Shape: (:short-decl LHS-LIST EXPRS). LHS is a list of (:var NAME).
+  ;; Extracts the names and falls through to bind-names-to-synth.
+  (fn (ctx decl)
+    (let ((lhs-list (nth decl 1)) (exprs (nth decl 2)))
+      (let ((names (map (fn (lhs)
+                          (cond
+                            (and (list? lhs) (= (first lhs) :var))
+                            (nth lhs 1)
+                            :else :unknown))
+                        lhs-list)))
+        (go-bind-names-to-synth ctx names exprs)))))
+
+(define
+  go-check-decl
+  ;; Top-level dispatcher: accepts any decl AST shape, returns extended
+  ;; context or :type-error.
+  (fn (ctx decl)
+    (cond
+      (and (list? decl) (= (first decl) :var-decl))   (go-check-var-decl ctx decl)
+      (and (list? decl) (= (first decl) :const-decl)) (go-check-var-decl ctx decl)
+      (and (list? decl) (= (first decl) :short-decl)) (go-check-short-decl ctx decl)
+      (and (list? decl) (= (first decl) :type-decl))
+      (let ((name (nth decl 1)) (ty (nth decl 2)))
+        (go-ctx-extend ctx name ty))
+      (and (list? decl) (= (first decl) :func-decl))
+      (go-check-func-decl ctx decl)
+      (and (list? decl) (= (first decl) :method-decl))
+      (go-check-method-decl ctx decl)
+      :else ctx)))
+
+;; ── method declarations and interface satisfaction ──────────────
+;; Methods are recorded in CTX under a mangled key
+;;   "#method/RECV-TYPE-NAME/METHOD-NAME"
+;; bound to the method's :ty-func signature. Interface satisfaction is
+;; a structural lookup over these keys (Go spec § Interface types:
+;; "anything with the matching method set satisfies the interface").
+
+(define
+  go-method-key
+  (fn (recv-ty-name method-name)
+    (str "#method/" recv-ty-name "/" method-name)))
+
+(define
+  go-extract-recv-ty-name
+  ;; Receiver type is T or *T; return the named type's name string.
+  (fn (recv-ty)
+    (cond
+      (and (list? recv-ty) (= (first recv-ty) :ty-name))
+      (nth recv-ty 1)
+      (and (list? recv-ty) (= (first recv-ty) :ty-ptr))
+      (go-extract-recv-ty-name (nth recv-ty 1))
+      :else nil)))
+
+(define
+  go-check-method-decl
+  ;; (list :method-decl RECV NAME PARAMS RESULTS BODY)
+  ;; Binds the method under the mangled key, then checks body with
+  ;; receiver + params extended.
+  (fn (ctx decl)
+    (let ((recv (nth decl 1)) (name (nth decl 2))
+          (params (nth decl 3)) (results (nth decl 4))
+          (body (nth decl 5)))
+      (let ((recv-ty (nth recv 2)))
+        (let ((recv-name (go-extract-recv-ty-name recv-ty)))
+          (let ((sig (list :ty-func
+                       (go-decl-params-to-ty-list params) results)))
+            (let ((ctx2
+                    (cond
+                      (= recv-name nil) ctx
+                      :else
+                      (go-ctx-extend ctx
+                        (go-method-key recv-name name) sig))))
+              (cond
+                (= body nil) ctx2
+                (and (list? body) (= (first body) :block))
+                (let ((body-ctx
+                        (go-extend-with-params
+                          (go-ctx-extend-field ctx2 recv) params)))
+                  (let ((err
+                          (go-check-block body-ctx
+                            (nth body 1) results)))
+                    (cond
+                      (go-type-error? err) err
+                      :else ctx2)))
+                :else ctx2))))))))
+
+(define
+  go-iface-elems-satisfied?
+  ;; Each :method element in ELEMS must have a matching method in CTX
+  ;; under #method/TY-NAME/M-NAME. :embed elements are skipped in v0
+  ;; (they'd need recursive interface resolution).
+  (fn (ctx ty-name elems)
+    (cond
+      (= (len elems) 0) true
+      :else
+      (let ((e (first elems)))
+        (cond
+          (= (first e) :method)
+          (let ((m-name (nth e 1)) (m-params (nth e 2))
+                (m-results (nth e 3)))
+            (let ((found (go-ctx-lookup ctx
+                           (go-method-key ty-name m-name))))
+              (cond
+                (= found nil) false
+                (and (= (nth found 1) m-params)
+                     (= (nth found 2) m-results))
+                (go-iface-elems-satisfied? ctx ty-name (rest elems))
+                :else false)))
+          (= (first e) :embed)
+          (go-iface-elems-satisfied? ctx ty-name (rest elems))
+          :else
+          (go-iface-elems-satisfied? ctx ty-name (rest elems)))))))
+
+(define
+  go-iface-satisfies?
+  ;; Does the type named TY-NAME satisfy the interface IFACE-TYPE
+  ;; under context CTX? Structural method-set match per Go spec.
+  (fn (ctx ty-name iface-type)
+    (cond
+      (not (and (list? iface-type) (= (first iface-type) :ty-interface)))
+      false
+      :else (go-iface-elems-satisfied? ctx ty-name (nth iface-type 1)))))
+
+;; ── function-decl checking ──────────────────────────────────────
+
+(define
+  go-repeat-ty
+  (fn (n ty acc)
+    (cond
+      (<= n 0) acc
+      :else (go-repeat-ty (- n 1) ty (cons ty acc)))))
+
+(define
+  go-decl-params-to-ty-list
+  ;; Flatten (:field NAMES TYPE) param groups into a list of types,
+  ;; one entry per name. For func-type signatures.
+  (fn (params)
+    (cond
+      (or (= params nil) (= (len params) 0)) (list)
+      :else
+      (let ((field (first params)))
+        (let ((names (nth field 1)) (ty (nth field 2)))
+          (let ((rest-tys (go-decl-params-to-ty-list (rest params))))
+            (go-repeat-ty (len names) ty rest-tys)))))))
+
+(define
+  go-extend-with-params
+  ;; Extend CTX with every binding in every (:field NAMES TYPE) param group.
+  (fn (ctx params)
+    (cond
+      (or (= params nil) (= (len params) 0)) ctx
+      :else
+      (go-extend-with-params
+        (go-ctx-extend-field ctx (first params))
+        (rest params)))))
+
+(define
+  go-check-return-list
+  ;; Each EXPR assignable to the corresponding RESULTS type.
+  ;; v0: lengths must match; multi-return funcs deferred.
+  (fn (ctx exprs results)
+    (cond
+      (and (= (len exprs) 0) (= (len results) 0)) :ok
+      (not (= (len exprs) (len results)))
+      (list :type-error :return-count-mismatch
+        (len exprs) (len results))
+      :else
+      (let ((r (go-check ctx (first exprs) (first results))))
+        (cond
+          (go-type-error? r) r
+          :else (go-check-return-list ctx (rest exprs) (rest results)))))))
+
+(define
+  go-check-assign
+  (fn (ctx stmt)
+    (let ((lhs-list (nth stmt 1)) (rhs-list (nth stmt 2)))
+      (cond
+        (not (= (len lhs-list) (len rhs-list)))
+        (list :type-error :assign-count-mismatch
+          (len lhs-list) (len rhs-list))
+        :else (go-check-assign-pairs ctx lhs-list rhs-list)))))
+
+(define
+  go-check-assign-pairs
+  (fn (ctx lhs-list rhs-list)
+    (cond
+      (= (len lhs-list) 0) :ok
+      :else
+      (let ((lhs-ty (go-synth ctx (first lhs-list))))
+        (cond
+          (go-type-error? lhs-ty) lhs-ty
+          :else
+          (let ((r (go-check ctx (first rhs-list) lhs-ty)))
+            (cond
+              (go-type-error? r) r
+              :else
+              (go-check-assign-pairs ctx (rest lhs-list)
+                (rest rhs-list)))))))))
+
+(define
+  go-check-stmt
+  ;; Returns either an extended CTX (decls), :ok (sealed stmts), or
+  ;; :type-error. RESULTS is the enclosing func's declared return types
+  ;; (used by :return).
+  (fn (ctx stmt results)
+    (cond
+      (and (list? stmt) (= (first stmt) :var-decl))
+      (go-check-decl ctx stmt)
+      (and (list? stmt) (= (first stmt) :const-decl))
+      (go-check-decl ctx stmt)
+      (and (list? stmt) (= (first stmt) :short-decl))
+      (go-check-decl ctx stmt)
+      (and (list? stmt) (= (first stmt) :type-decl))
+      (go-check-decl ctx stmt)
+      (and (list? stmt) (= (first stmt) :return))
+      (let ((exprs (nth stmt 1)))
+        (let ((err (go-check-return-list ctx exprs results)))
+          (cond (go-type-error? err) err :else ctx)))
+      (and (list? stmt) (= (first stmt) :block))
+      (let ((err (go-check-block ctx (nth stmt 1) results)))
+        (cond (go-type-error? err) err :else ctx))
+      (and (list? stmt) (= (first stmt) :assign))
+      (let ((err (go-check-assign ctx stmt)))
+        (cond (go-type-error? err) err :else ctx))
+      :else
+      (let ((t (go-synth ctx stmt)))
+        (cond (go-type-error? t) t :else ctx)))))
+
+(define
+  go-check-block
+  ;; Thread ctx through stmts; if any stmt is a decl, its extension
+  ;; propagates to subsequent stmts. Returns :ok or :type-error.
+  (fn (ctx stmts results)
+    (cond
+      (or (= stmts nil) (= (len stmts) 0)) :ok
+      :else
+      (let ((r (go-check-stmt ctx (first stmts) results)))
+        (cond
+          (go-type-error? r) r
+          :else (go-check-block r (rest stmts) results))))))
+
+(define
+  go-check-func-decl
+  ;; Bind the function in the outer ctx (so recursion works), extend
+  ;; ctx with type params + value params, check the body. Returns the
+  ;; outer ctx with the function bound, or :type-error.
+  ;;
+  ;; Type parameters become opaque type variables in the body's ctx:
+  ;; each name `T` is bound as a type alias to (:ty-param "T") so the
+  ;; checker treats references to T as "this type", not "unknown".
+  ;; Constraint enforcement (T satisfies `comparable` etc.) is a
+  ;; later refinement; v0 just allows any operation that's polymorphic
+  ;; under the constraint `any`.
+  (fn (ctx decl)
+    (let ((name (nth decl 1)) (params (nth decl 2))
+          (results (nth decl 3)) (body (nth decl 4))
+          (type-params (cond (> (len decl) 5) (nth decl 5) :else nil)))
+      (let ((fn-ty
+              (list :ty-func
+                (go-decl-params-to-ty-list params) results)))
+        (let ((ctx-with-fn (go-ctx-extend ctx name fn-ty)))
+          (cond
+            (= body nil) ctx-with-fn
+            (and (list? body) (= (first body) :block))
+            (let ((body-ctx
+                    (go-extend-with-type-params
+                      (go-extend-with-params ctx-with-fn params)
+                      type-params)))
+              (let ((err
+                      (go-check-block body-ctx (nth body 1) results)))
+                (cond
+                  (go-type-error? err) err
+                  :else ctx-with-fn)))
+            :else ctx-with-fn))))))
+
+(define
+  go-extend-with-type-params
+  ;; Each (:field NAMES CONSTRAINT) field contributes opaque type
+  ;; vars: bind each NAME as a type alias to (:ty-param NAME). The
+  ;; constraint type is stored alongside so future "constraint
+  ;; satisfaction" checks can find it; for v0 it's informational.
+  (fn (ctx type-params)
+    (cond
+      (or (= type-params nil) (= (len type-params) 0)) ctx
+      :else
+      (let ((field (first type-params)))
+        (let ((names (nth field 1)) (constraint (nth field 2)))
+          (go-extend-with-type-params
+            (go-extend-with-type-param-names ctx names constraint)
+            (rest type-params)))))))
+
+(define
+  go-extend-with-type-param-names
+  (fn (ctx names constraint)
+    (cond
+      (= (len names) 0) ctx
+      :else
+      (let ((nm (first names)))
+        (go-extend-with-type-param-names
+          (go-ctx-extend ctx nm
+            (list :ty-param nm constraint))
+          (rest names) constraint)))))

lib/mod/activity.sx

@@ -0,0 +1,40 @@
+;; lib/mod/activity.sx — export decisions as ActivityPub-shaped events.
+;;
+;; The rose-ash platform propagates cross-domain effects as ActivityPub-shaped
+;; activities. A moderation decision maps to a moderation verb so the rest of the
+;; platform (and federated peers) can act on it: remove→Delete, ban→Block,
+;; hide/escalate→Flag, keep→no activity. The precise mod action is preserved in
+;; :action so a consumer can disambiguate (e.g. hide vs escalate, both Flag).
+
+(define
+  mod/action->verb
+  (fn
+    (action)
+    (cond
+      ((= action "remove") "Delete")
+      ((= action "ban") "Block")
+      ((= action "hide") "Flag")
+      ((= action "escalate") "Flag")
+      (true nil))))
+
+(define
+  mod/decision->activity
+  (fn
+    (d actor)
+    (let
+      ((verb (mod/action->verb (get d :action))))
+      (if (nil? verb) nil {:type verb :action (get d :action) :actor actor :summary (str "moderation/" (get d :action) " via " (get d :rule)) :object (get d :report-id) :rule (get d :rule)}))))
+
+;; map a batch of decisions to activities, dropping the no-op keeps
+(define
+  mod/decisions->activities
+  (fn
+    (decisions actor)
+    (reduce
+      (fn
+        (acc d)
+        (let
+          ((a (mod/decision->activity d actor)))
+          (if (nil? a) acc (append acc (list a)))))
+      (list)
+      decisions)))

lib/mod/api.sx

@@ -0,0 +1,163 @@
+;; lib/mod/api.sx — report registry + lifecycle façade + public entry points.
+;;
+;; mod/report files a report (assigning a sequential id) and opens a lifecycle
+;; case for it; mod/add-evidence accumulates evidence; mod/decide runs the engine
+;; and commits to the audit log. The lifecycle façade (mod/triage, mod/resolve,
+;; mod/review, mod/appeal, mod/finalize) drives the per-report case through its
+;; states, logging each committed decision to the audit trail.
+
+(define mod/*reports* (list))
+(define mod/*cases* (list))
+(define mod/*counter* 0)
+(define mod/*rules* mod/default-rules)
+
+(define
+  mod/reset!
+  (fn
+    ()
+    (begin
+      (set! mod/*reports* (list))
+      (set! mod/*cases* (list))
+      (set! mod/*counter* 0)
+      (mod/audit-reset!))))
+
+(define
+  mod/report
+  (fn
+    (by about reason)
+    (begin
+      (set! mod/*counter* (+ mod/*counter* 1))
+      (let
+        ((id (str "r" mod/*counter*)))
+        (let
+          ((r (mod/mk-report id by about reason)))
+          (begin
+            (append! mod/*reports* r)
+            (append! mod/*cases* {:id id :case (mod/mk-case r)})
+            r))))))
+
+(define
+  mod/get-report
+  (fn
+    (id)
+    (reduce
+      (fn (acc r) (if (= (mod/report-id r) id) r acc))
+      nil
+      mod/*reports*)))
+
+(define
+  mod/add-evidence
+  (fn
+    (id kind val)
+    (let
+      ((r (mod/get-report id)))
+      (if
+        (nil? r)
+        nil
+        (let
+          ((updated (mod/attach-evidence r (mod/mk-evidence kind val))))
+          (begin
+            (set!
+              mod/*reports*
+              (map
+                (fn (x) (if (= (mod/report-id x) id) updated x))
+                mod/*reports*))
+            updated))))))
+
+(define
+  mod/decide
+  (fn
+    (id)
+    (let
+      ((r (mod/get-report id)))
+      (if
+        (nil? r)
+        nil
+        (let
+          ((d (mod/decide-report r mod/*reports* mod/*rules*)))
+          (begin (mod/log-decision! d (mod/report-evidence r)) d))))))
+
+;; ── lifecycle façade over the case registry ──
+
+(define
+  mod/case-of
+  (fn
+    (id)
+    (reduce
+      (fn (acc rec) (if (= (get rec :id) id) (get rec :case) acc))
+      nil
+      mod/*cases*)))
+
+(define
+  mod/case-store!
+  (fn
+    (id c)
+    (set!
+      mod/*cases*
+      (map
+        (fn (rec) (if (= (get rec :id) id) {:id id :case c} rec))
+        mod/*cases*))))
+
+;; apply a lifecycle op to the stored case, persist it, and (when a decision was
+;; committed cleanly) append it to the audit log; returns the updated case
+(define
+  mod/case-apply!
+  (fn
+    (id op log?)
+    (let
+      ((c (mod/case-of id)))
+      (if
+        (nil? c)
+        nil
+        (let
+          ((c2 (op c)))
+          (begin
+            (mod/case-store! id c2)
+            (when
+              log?
+              (when
+                (nil? (mod/case-error c2))
+                (let
+                  ((d (mod/case-decision c2)))
+                  (if
+                    (nil? d)
+                    nil
+                    (mod/log-decision!
+                      d
+                      (mod/report-evidence (mod/case-report c2)))))))
+            c2))))))
+
+(define
+  mod/triage
+  (fn
+    (id)
+    (mod/case-apply!
+      id
+      (fn (c) (mod/case-triage c mod/*reports* mod/*rules*))
+      false)))
+
+(define
+  mod/resolve
+  (fn (id) (mod/case-apply! id (fn (c) (mod/case-resolve c)) true)))
+
+(define
+  mod/review
+  (fn
+    (id kind val)
+    (mod/case-apply!
+      id
+      (fn (c) (mod/case-review c kind val mod/*reports* mod/*rules*))
+      true)))
+
+(define
+  mod/appeal
+  (fn
+    (id kind val)
+    (mod/case-apply!
+      id
+      (fn (c) (mod/case-appeal c kind val mod/*reports* mod/*rules*))
+      true)))
+
+(define
+  mod/finalize
+  (fn (id) (mod/case-apply! id (fn (c) (mod/case-finalize c)) false)))

lib/mod/audit.sx

@@ -0,0 +1,54 @@
+;; lib/mod/audit.sx — append-only decision log.
+;;
+;; Every decision the api commits is recorded as an immutable audit entry holding
+;; the decision (action + matching rule), the proof tree (the derivation that
+;; justified it), and a snapshot of the evidence in force at decision time. The
+;; log is append-only: entries are never mutated or removed, only appended, each
+;; with a monotonic sequence number. Retrieval is by report id (full history) or
+;; by sequence.
+
+(define mod/*audit-log* (list))
+(define mod/*audit-seq* 0)
+
+(define
+  mod/audit-reset!
+  (fn
+    ()
+    (begin (set! mod/*audit-log* (list)) (set! mod/*audit-seq* 0))))
+
+(define mod/mk-audit-entry (fn (seq decision evidence-snapshot) {:action (get decision :action) :evidence evidence-snapshot :proof (get decision :proof) :rule (get decision :rule) :report-id (get decision :report-id) :seq seq}))
+
+(define
+  mod/log-decision!
+  (fn
+    (decision evidence-snapshot)
+    (begin
+      (set! mod/*audit-seq* (+ mod/*audit-seq* 1))
+      (let
+        ((entry (mod/mk-audit-entry mod/*audit-seq* decision evidence-snapshot)))
+        (begin (append! mod/*audit-log* entry) entry)))))
+
+;; entries for one report, in chronological (sequence) order
+(define
+  mod/audit
+  (fn
+    (id)
+    (reduce
+      (fn
+        (acc e)
+        (if (= (get e :report-id) id) (append acc (list e)) acc))
+      (list)
+      mod/*audit-log*)))
+
+(define mod/audit-all (fn () mod/*audit-log*))
+(define mod/audit-count (fn () (len mod/*audit-log*)))
+
+;; most recent decision logged for a report (nil if none)
+(define
+  mod/audit-latest
+  (fn
+    (id)
+    (reduce
+      (fn (acc e) (if (= (get e :report-id) id) e acc))
+      nil
+      mod/*audit-log*)))

lib/mod/batch.sx

@@ -0,0 +1,55 @@
+;; lib/mod/batch.sx — batch triage + corpus analytics.
+;;
+;; Operational layer: decide a whole queue of reports at once, summarize the
+;; outcomes by action, and measure which rules actually fire across a corpus.
+;; mod/never-fired is the empirical complement to lint's static unreachable check
+;; (Ext 5): lint finds rules that CAN'T fire by structure; never-fired finds rules
+;; that DIDN'T fire on real data.
+
+(define
+  mod/decide-batch
+  (fn
+    (reports rules)
+    (map (fn (r) (mod/decide-report r reports rules)) reports)))
+
+(define
+  mod/count-action
+  (fn
+    (decisions action)
+    (reduce
+      (fn (acc d) (if (= (get d :action) action) (+ acc 1) acc))
+      0
+      decisions)))
+
+(define mod/action-histogram (fn (decisions) {:keep (mod/count-action decisions "keep") :remove (mod/count-action decisions "remove") :escalate (mod/count-action decisions "escalate") :hide (mod/count-action decisions "hide") :ban (mod/count-action decisions "ban")}))
+
+(define
+  mod/rule-fire-count
+  (fn
+    (decisions rule-name)
+    (reduce
+      (fn (acc d) (if (= (get d :rule) rule-name) (+ acc 1) acc))
+      0
+      decisions)))
+
+(define
+  mod/rule-coverage
+  (fn
+    (reports rules)
+    (let
+      ((decisions (mod/decide-batch reports rules)))
+      (map (fn (rule) {:rule (mod/rule-name rule) :fired (mod/rule-fire-count decisions (mod/rule-name rule))}) rules))))
+
+(define
+  mod/never-fired
+  (fn
+    (reports rules)
+    (reduce
+      (fn
+        (acc c)
+        (if
+          (= (get c :fired) 0)
+          (append acc (list (get c :rule)))
+          acc))
+      (list)
+      (mod/rule-coverage reports rules))))

lib/mod/conformance.conf

@@ -0,0 +1,60 @@
+# Mod conformance config — sourced by lib/guest/conformance.sh.
+
+LANG_NAME=mod
+MODE=dict
+
+PRELOADS=(
+  lib/guest/pratt.sx
+  lib/prolog/tokenizer.sx
+  lib/prolog/parser.sx
+  lib/prolog/runtime.sx
+  lib/prolog/query.sx
+  lib/prolog/compiler.sx
+  lib/mod/schema.sx
+  lib/mod/policy.sx
+  lib/mod/defrule.sx
+  lib/mod/engine.sx
+  lib/mod/explain.sx
+  lib/mod/severity.sx
+  lib/mod/offenders.sx
+  lib/mod/quorum.sx
+  lib/mod/trace.sx
+  lib/mod/whatif.sx
+  lib/mod/batch.sx
+  lib/mod/temporal.sx
+  lib/mod/sla.sx
+  lib/mod/wire.sx
+  lib/mod/activity.sx
+  lib/mod/policies.sx
+  lib/mod/pipeline.sx
+  lib/mod/lifecycle.sx
+  lib/mod/audit.sx
+  lib/mod/api.sx
+  lib/mod/fed.sx
+  lib/mod/link.sx
+  lib/mod/lint.sx
+)
+
+SUITES=(
+  "decide:lib/mod/tests/decide.sx:(mod-decide-tests-run!)"
+  "audit:lib/mod/tests/audit.sx:(mod-audit-tests-run!)"
+  "escalation:lib/mod/tests/escalation.sx:(mod-escalation-tests-run!)"
+  "fed:lib/mod/tests/fed.sx:(mod-fed-tests-run!)"
+  "extensions:lib/mod/tests/extensions.sx:(mod-extensions-tests-run!)"
+  "link:lib/mod/tests/link.sx:(mod-link-tests-run!)"
+  "lint:lib/mod/tests/lint.sx:(mod-lint-tests-run!)"
+  "severity:lib/mod/tests/severity.sx:(mod-severity-tests-run!)"
+  "offenders:lib/mod/tests/offenders.sx:(mod-offenders-tests-run!)"
+  "quorum:lib/mod/tests/quorum.sx:(mod-quorum-tests-run!)"
+  "trace:lib/mod/tests/trace.sx:(mod-trace-tests-run!)"
+  "whatif:lib/mod/tests/whatif.sx:(mod-whatif-tests-run!)"
+  "batch:lib/mod/tests/batch.sx:(mod-batch-tests-run!)"
+  "temporal:lib/mod/tests/temporal.sx:(mod-temporal-tests-run!)"
+  "sla:lib/mod/tests/sla.sx:(mod-sla-tests-run!)"
+  "wire:lib/mod/tests/wire.sx:(mod-wire-tests-run!)"
+  "disjunction:lib/mod/tests/disjunction.sx:(mod-disjunction-tests-run!)"
+  "activity:lib/mod/tests/activity.sx:(mod-activity-tests-run!)"
+  "policies:lib/mod/tests/policies.sx:(mod-policies-tests-run!)"
+  "defrule:lib/mod/tests/defrule.sx:(mod-defrule-tests-run!)"
+  "pipeline:lib/mod/tests/pipeline.sx:(mod-pipeline-tests-run!)"
+)

lib/mod/conformance.sh

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+# Thin wrapper — see lib/guest/conformance.sh and lib/mod/conformance.conf.
+exec bash "$(dirname "$0")/../guest/conformance.sh" "$(dirname "$0")/conformance.conf" "$@"

lib/mod/defrule.sx

@@ -0,0 +1,16 @@
+;; lib/mod/defrule.sx — ergonomic rule / ruleset construction.
+;;
+;; The roadmap sketched a (defrule action :when conditions) surface. Conditions
+;; already evaluate to plain data, so this needs no macro — variadic functions
+;; suffice: mod/defrule collects its trailing condition forms via &rest (dropping
+;; the explicit outer (list ...)), and mod/ruleset assembles rules the same way.
+;;
+;;   (mod/ruleset
+;;     (mod/defrule "spam-hide" :hide (list :classification "spam"))
+;;     (mod/defrule "default-keep" :keep))
+
+(define
+  mod/defrule
+  (fn (name action &rest conds) (mod/mk-rule name action conds)))
+
+(define mod/ruleset (fn (&rest rules) rules))

lib/mod/engine.sx

@@ -0,0 +1,64 @@
+;; lib/mod/engine.sx — decide a report by querying the policy program.
+;;
+;; build-program assembles the report's facts plus the compiled policy clauses;
+;; decide-report runs the Prolog query and returns a decision. A decision is a
+;; proof, not a bare keyword: it carries the matching rule, the conditions it
+;; required, the evidence that satisfied them, and a derivation — the proof tree.
+;;
+;; The proof tree is built constructively: for the matching rule, each body goal
+;; is re-queried against the same DB with the report id bound, recording the goal
+;; text, whether it was solved, and the bindings that satisfied it. That is a
+;; genuine derivation drawn from the Prolog database, ready for the audit trail.
+
+(define
+  mod/find-rule
+  (fn
+    (rules name)
+    (reduce
+      (fn
+        (acc r)
+        (if (nil? acc) (if (= (mod/rule-name r) name) r acc) acc))
+      nil
+      rules)))
+
+(define
+  mod/build-program
+  (fn
+    (r count rules)
+    (str (mod/report-facts r count) "\n" (mod/rules->program rules))))
+
+(define
+  mod/proof-goals
+  (fn
+    (db id conds)
+    (if
+      (empty? conds)
+      (list {:solved true :goal "true" :bindings {}})
+      (map
+        (fn
+          (c)
+          (let
+            ((g (mod/cond->goal c id)))
+            (let ((sols (pl-query-all db g))) {:solved (if (empty? sols) false true) :goal g :bindings (if (empty? sols) {} (first sols))})))
+        conds))))
+
+(define
+  mod/decide-report
+  (fn
+    (r reports rules)
+    (let
+      ((count (mod/report-count (mod/report-about r) reports))
+        (kinds (mod/classify-keywords r))
+        (id (mod/report-id r)))
+      (let
+        ((program (mod/build-program r count rules)))
+        (let
+          ((db (pl-load program)))
+          (let
+            ((sol (pl-query-one db (str "policy_action(" id ", Action, Rule)"))))
+            (if
+              (nil? sol)
+              {:action "keep" :proof {:goals (list) :evidence kinds :conditions (list) :rule "none" :count count} :report-id id :rule "none"}
+              (let
+                ((rname (dict-get sol "Rule")))
+                (let ((rule (mod/find-rule rules rname))) {:action (mod/rule-action rule) :proof {:goals (mod/proof-goals db id (mod/rule-when rule)) :evidence kinds :conditions (mod/rule-when rule) :rule rname :count count} :report-id id :rule rname})))))))))

lib/mod/explain.sx

@@ -0,0 +1,55 @@
+;; lib/mod/explain.sx — human-readable proof explanation.
+;;
+;; Turns a decision (from mod/decide-report, or any audit entry) into a readable
+;; multi-line "why": the action, the rule that fired, the evidence in play, and
+;; the derivation goal-by-goal with [proved]/[unproved] marks and the unification
+;; bindings that satisfied each goal. Pure SX over the Phase-2 proof tree.
+
+(define
+  mod/explain-binds
+  (fn
+    (binds)
+    (mod/join-with
+      ", "
+      (map (fn (k) (str k "=" (dict-get binds k))) (keys binds)))))
+
+(define
+  mod/explain-goal
+  (fn
+    (g)
+    (let
+      ((mark (if (get g :solved) "  [proved] " "  [unproved] "))
+        (binds (get g :bindings)))
+      (if
+        (empty? (keys binds))
+        (str mark (get g :goal))
+        (str mark (get g :goal) "  {" (mod/explain-binds binds) "}")))))
+
+(define
+  mod/explain-evidence
+  (fn
+    (evidence)
+    (if
+      (empty? evidence)
+      "Evidence: (none)"
+      (str "Evidence: " (mod/join-with ", " evidence)))))
+
+(define
+  mod/explain
+  (fn
+    (decision)
+    (let
+      ((id (get decision :report-id))
+        (action (get decision :action))
+        (rule (get decision :rule))
+        (proof (get decision :proof)))
+      (let
+        ((goals (get proof :goals)) (evidence (get proof :evidence)))
+        (mod/join-with
+          "\n"
+          (append
+            (list
+              (str "Report " id ": " action " (rule: " rule ")")
+              (mod/explain-evidence evidence)
+              "Because:")
+            (map mod/explain-goal goals)))))))

lib/mod/fed.sx

@@ -0,0 +1,145 @@
+;; lib/mod/fed.sx — federation: cross-instance reports, decision sharing, trust,
+;; revocation. fed-sx itself is mocked here (an in-memory outbox); the real wire
+;; transport would replace mod/fed-send!.
+;;
+;; Trust is advisory by default (the hard rule): a peer's decision only binds
+;; locally when (mod/trusted? peer :mod) holds. An untrusted peer's decision is
+;; recorded as a suggestion in the advisory log and is NOT applied. Local
+;; decisions propagate outward via the outbox. Revocation undoes a locally
+;; applied action when its proof is invalidated, notifying the origin peer.
+
+(define mod/*fed-trust* (list))     ;; {:peer :scope}
+(define mod/*fed-outbox* (list))    ;; {:to :type :payload}
+(define mod/*fed-advisory* (list))  ;; {:peer :decision} — received, not applied
+(define mod/*fed-applied* (list))   ;; {:report-id :action :origin :revoked}
+(define mod/*fed-origins* (list))   ;; {:id :origin}
+
+(define
+  mod/fed-reset!
+  (fn
+    ()
+    (begin
+      (set! mod/*fed-trust* (list))
+      (set! mod/*fed-outbox* (list))
+      (set! mod/*fed-advisory* (list))
+      (set! mod/*fed-applied* (list))
+      (set! mod/*fed-origins* (list)))))
+
+;; ── trust model ──
+
+(define
+  mod/trust-match?
+  (fn
+    (t peer scope)
+    (if (= (get t :peer) peer) (= (get t :scope) scope) false)))
+
+(define
+  mod/grant-trust
+  (fn (peer scope) (begin (append! mod/*fed-trust* {:scope scope :peer peer}) true)))
+
+(define
+  mod/revoke-trust
+  (fn
+    (peer scope)
+    (set!
+      mod/*fed-trust*
+      (reduce
+        (fn
+          (acc t)
+          (if (mod/trust-match? t peer scope) acc (append acc (list t))))
+        (list)
+        mod/*fed-trust*))))
+
+(define
+  mod/trusted?
+  (fn
+    (peer scope)
+    (mod/any? (fn (t) (mod/trust-match? t peer scope)) mod/*fed-trust*)))
+
+;; ── cross-instance reports ──
+
+(define
+  mod/fed-receive-report
+  (fn
+    (peer by about reason)
+    (let
+      ((r (mod/report by about reason)))
+      (begin (append! mod/*fed-origins* {:id (mod/report-id r) :origin peer}) r))))
+
+(define
+  mod/report-origin
+  (fn
+    (id)
+    (reduce
+      (fn (acc o) (if (= (get o :id) id) (get o :origin) acc))
+      "local"
+      mod/*fed-origins*)))
+
+;; ── decision sharing (mock fed-sx send) ──
+
+(define
+  mod/fed-send!
+  (fn (to type payload) (begin (append! mod/*fed-outbox* {:type type :to to :payload payload}) true)))
+
+(define mod/fed-outbox (fn () mod/*fed-outbox*))
+
+(define
+  mod/fed-share-decision
+  (fn
+    (decision peers)
+    (reduce
+      (fn
+        (acc p)
+        (begin (mod/fed-send! p "decision" decision) (append acc (list p))))
+      (list)
+      peers)))
+
+;; ── receiving a peer's decision (advisory unless trusted) ──
+
+(define
+  mod/fed-applied-action
+  (fn
+    (report-id)
+    (reduce
+      (fn (acc a) (if (= (get a :report-id) report-id) a acc))
+      nil
+      mod/*fed-applied*)))
+
+(define
+  mod/fed-receive-decision
+  (fn
+    (peer decision)
+    (if
+      (mod/trusted? peer :mod)
+      (begin (append! mod/*fed-applied* {:revoked false :action (get decision :action) :report-id (get decision :report-id) :origin peer}) {:advisory false :peer peer :applied true :decision decision})
+      (begin (append! mod/*fed-advisory* {:peer peer :decision decision}) {:advisory true :peer peer :applied false :decision decision}))))
+
+;; ── revocation ──
+
+(define
+  mod/fed-revoke!
+  (fn
+    (report-id reason)
+    (begin
+      (set!
+        mod/*fed-applied*
+        (map
+          (fn (a) (if (= (get a :report-id) report-id) {:revoked true :action (get a :action) :report-id (get a :report-id) :origin (get a :origin)} a))
+          mod/*fed-applied*))
+      (mod/fed-send! (mod/report-origin report-id) "revocation" {:report-id report-id :reason reason})
+      report-id)))
+
+;; re-run the engine; if the action no longer holds, the prior decision's proof
+;; is invalidated — revoke the applied moderation.
+(define
+  mod/fed-revoke-if-invalidated
+  (fn
+    (report decision reports rules)
+    (let
+      ((d2 (mod/decide-report report reports rules)))
+      (if
+        (= (get d2 :action) (get decision :action))
+        {:revoked false :decision d2}
+        (begin
+          (mod/fed-revoke! (get decision :report-id) "proof invalidated")
+          {:revoked true :decision d2})))))

lib/mod/lifecycle.sx

@@ -0,0 +1,160 @@
+;; lib/mod/lifecycle.sx — report lifecycle state machine (pure SX over the engine).
+;;
+;; Lifecycle state is deliberately separate from policy: the Prolog rules answer
+;; "what action?", this module answers "where in the process is this report?".
+;;
+;;   :open ──triage──▶ :triaged ──resolve/review──▶ :decided ──appeal──▶ :appealed
+;;                                                      │                    │
+;;                                                      └────finalize───▶ :final ◀┘
+;;
+;; A case is an immutable value {:report :state :decision :tier :error :history}.
+;; Every transition returns a NEW case; illegal transitions return the case
+;; unchanged with :error set. Tiers: triage runs the engine (auto-tier); a
+;; terminal action (hide/remove/keep) resolves immediately, an :escalate action
+;; flags the case for human review (human-tier) before it can be resolved.
+
+(define mod/case* (fn (report state decision tier err history) {:history history :state state :report report :error err :tier tier :decision decision}))
+
+(define
+  mod/mk-case
+  (fn (report) (mod/case* report "open" nil nil nil (list))))
+
+(define mod/case-report (fn (c) (get c :report)))
+(define mod/case-state (fn (c) (get c :state)))
+(define mod/case-decision (fn (c) (get c :decision)))
+(define mod/case-tier (fn (c) (get c :tier)))
+(define mod/case-error (fn (c) (get c :error)))
+(define mod/case-history (fn (c) (get c :history)))
+
+;; ── transition table ──
+
+(define mod/lc-transitions {:final (list) :appealed (list "final") :decided (list "appealed" "final") :open (list "triaged") :triaged (list "decided")})
+
+(define mod/member? (fn (x lst) (mod/any? (fn (y) (= y x)) lst)))
+
+(define
+  mod/lc-can-transition?
+  (fn
+    (from to)
+    (let
+      ((outs (get mod/lc-transitions from)))
+      (if (nil? outs) false (mod/member? to outs)))))
+
+;; ── core transition: validate, record history, or flag :error ──
+
+(define
+  mod/case-goto
+  (fn
+    (c to note report decision tier)
+    (let
+      ((from (mod/case-state c)))
+      (if
+        (mod/lc-can-transition? from to)
+        (mod/case*
+          report
+          to
+          decision
+          tier
+          nil
+          (append (mod/case-history c) (list {:note note :to to :from from})))
+        (mod/case*
+          (mod/case-report c)
+          from
+          (mod/case-decision c)
+          (mod/case-tier c)
+          (str "illegal transition: " from " -> " to)
+          (mod/case-history c))))))
+
+(define
+  mod/case-error-set
+  (fn
+    (c msg)
+    (mod/case*
+      (mod/case-report c)
+      (mod/case-state c)
+      (mod/case-decision c)
+      (mod/case-tier c)
+      msg
+      (mod/case-history c))))
+
+;; ── lifecycle operations ──
+
+;; :open → :triaged — run the auto-tier first pass.
+(define
+  mod/case-triage
+  (fn
+    (c reports rules)
+    (let
+      ((d (mod/decide-report (mod/case-report c) reports rules)))
+      (let
+        ((tier (if (= (get d :action) "escalate") "human" "auto")))
+        (mod/case-goto
+          c
+          "triaged"
+          "auto-tier first pass"
+          (mod/case-report c)
+          d
+          tier)))))
+
+;; :triaged → :decided — auto-tier resolves; human-tier is blocked until review.
+(define
+  mod/case-resolve
+  (fn
+    (c)
+    (if
+      (= (mod/case-tier c) "human")
+      (mod/case-error-set c "awaiting human review (escalated)")
+      (mod/case-goto
+        c
+        "decided"
+        "auto-tier resolved"
+        (mod/case-report c)
+        (mod/case-decision c)
+        (mod/case-tier c)))))
+
+;; :triaged → :decided — human review: attach evidence, re-decide, resolve.
+(define
+  mod/case-review
+  (fn
+    (c kind val reports rules)
+    (let
+      ((nr (mod/attach-evidence (mod/case-report c) (mod/mk-evidence kind val))))
+      (let
+        ((d (mod/decide-report nr reports rules)))
+        (mod/case-goto c "decided" (str "human review: " kind) nr d "human")))))
+
+;; :decided → :appealed — appeal: attach evidence, re-decide (may override).
+(define
+  mod/case-appeal
+  (fn
+    (c kind val reports rules)
+    (let
+      ((nr (mod/attach-evidence (mod/case-report c) (mod/mk-evidence kind val))))
+      (let
+        ((d (mod/decide-report nr reports rules)))
+        (mod/case-goto
+          c
+          "appealed"
+          (str "appeal: " kind)
+          nr
+          d
+          (mod/case-tier c))))))
+
+;; :decided | :appealed → :final
+(define
+  mod/case-finalize
+  (fn
+    (c)
+    (mod/case-goto
+      c
+      "final"
+      "finalized"
+      (mod/case-report c)
+      (mod/case-decision c)
+      (mod/case-tier c))))
+
+(define
+  mod/case-action
+  (fn
+    (c)
+    (let ((d (mod/case-decision c))) (if (nil? d) nil (get d :action)))))

lib/mod/link.sx

@@ -0,0 +1,92 @@
+;; lib/mod/link.sx — report linking + deduplication.
+;;
+;; Reports about the same subject form a cluster; identical reports (same
+;; reporter + subject + reason) are duplicates. Linking is Prolog-backed: all
+;; report facts are loaded and related ids are found by unification — the same
+;; relational substrate the policy engine uses, here for retrieval rather than
+;; decision. Dedup is pure SX over a normalized link key.
+
+(define
+  mod/link-key
+  (fn
+    (r)
+    (str
+      (mod/report-by r)
+      "|"
+      (mod/report-about r)
+      "|"
+      (downcase (mod/report-reason r)))))
+
+(define
+  mod/dedup-reports
+  (fn
+    (reports)
+    (reduce
+      (fn
+        (acc r)
+        (if
+          (mod/any? (fn (x) (= (mod/link-key x) (mod/link-key r))) acc)
+          acc
+          (append acc (list r))))
+      (list)
+      reports)))
+
+(define
+  mod/duplicate-count
+  (fn (reports) (- (len reports) (len (mod/dedup-reports reports)))))
+
+;; ── Prolog-backed relational retrieval ──
+
+(define
+  mod/report-rel-facts
+  (fn
+    (reports)
+    (mod/join-with
+      "\n"
+      (map
+        (fn
+          (r)
+          (str
+            "report("
+            (mod/report-id r)
+            ", "
+            (mod/pl-quote (mod/report-by r))
+            ", "
+            (mod/pl-quote (mod/report-about r))
+            ")."))
+        reports))))
+
+(define
+  mod/related-ids
+  (fn
+    (subject reports)
+    (let
+      ((db (pl-load (mod/report-rel-facts reports))))
+      (map
+        (fn (sol) (dict-get sol "Id"))
+        (pl-query-all db (str "report(Id, _, " (mod/pl-quote subject) ")"))))))
+
+(define
+  mod/reporters-of
+  (fn
+    (subject reports)
+    (let
+      ((db (pl-load (mod/report-rel-facts reports))))
+      (map
+        (fn (sol) (dict-get sol "By"))
+        (pl-query-all db (str "report(_, By, " (mod/pl-quote subject) ")"))))))
+
+(define
+  mod/distinct
+  (fn
+    (items)
+    (reduce
+      (fn
+        (acc x)
+        (if (mod/any? (fn (y) (= y x)) acc) acc (append acc (list x))))
+      (list)
+      items)))
+
+(define
+  mod/distinct-reporters-of
+  (fn (subject reports) (mod/distinct (mod/reporters-of subject reports))))

lib/mod/lint.sx

@@ -0,0 +1,69 @@
+;; lib/mod/lint.sx — static analysis of a policy rule set.
+;;
+;; Because precedence is "first matching clause wins" (pl-query-one), the rule
+;; order has correctness consequences a moderator can get wrong: a rule placed
+;; after an unconditional (empty :when) rule can never fire, and a rule set with
+;; no unconditional rule may leave some reports undecided. lint-rules surfaces
+;; these without running the engine.
+
+(define mod/rule-unconditional? (fn (r) (empty? (mod/rule-when r))))
+
+;; names of rules that follow the first unconditional rule — structurally dead,
+;; since the unconditional rule always matches first
+(define
+  mod/unreachable-rules
+  (fn
+    (rules)
+    (get
+      (reduce
+        (fn
+          (acc r)
+          (if
+            (get acc :hit)
+            {:dead (append (get acc :dead) (list (mod/rule-name r))) :hit true}
+            (if (mod/rule-unconditional? r) {:dead (get acc :dead) :hit true} acc)))
+        {:dead (list) :hit false}
+        rules)
+      :dead)))
+
+(define
+  mod/has-catchall?
+  (fn (rules) (mod/any? mod/rule-unconditional? rules)))
+
+(define
+  mod/count-eq
+  (fn
+    (x lst)
+    (reduce (fn (a y) (if (= y x) (+ a 1) a)) 0 lst)))
+
+(define
+  mod/duplicate-rule-names
+  (fn
+    (rules)
+    (let
+      ((names (map mod/rule-name rules)))
+      (mod/distinct
+        (reduce
+          (fn
+            (acc n)
+            (if
+              (< 1 (mod/count-eq n names))
+              (append acc (list n))
+              acc))
+          (list)
+          names)))))
+
+(define mod/lint-rules (fn (rules) {:duplicate-names (mod/duplicate-rule-names rules) :has-catchall (mod/has-catchall? rules) :unreachable (mod/unreachable-rules rules)}))
+
+;; a rule set is well-formed when nothing is dead, it has a catch-all, and rule
+;; names are unique
+(define
+  mod/rules-ok?
+  (fn
+    (rules)
+    (let
+      ((l (mod/lint-rules rules)))
+      (if
+        (empty? (get l :unreachable))
+        (if (get l :has-catchall) (empty? (get l :duplicate-names)) false)
+        false))))

lib/mod/offenders.sx

@@ -0,0 +1,59 @@
+;; lib/mod/offenders.sx — repeat-offender escalation (audit log as evidence).
+;;
+;; The append-only audit trail is itself a source of evidence: a subject already
+;; sanctioned several times is a repeat offender. mod/decide-escalating decides a
+;; report normally, then — if the action is a sanction and the subject has at
+;; least k PRIOR sanctions in the audit log — upgrades it to :ban. This is the one
+;; place a decision depends on history beyond the single report, and it reads that
+;; history from the audit log rather than re-deriving it.
+
+(define
+  mod/sanction?
+  (fn
+    (action)
+    (mod/any? (fn (a) (= a action)) (list "hide" "remove" "ban"))))
+
+;; count of prior sanctioning decisions in the audit log about a subject
+(define
+  mod/subject-sanctions
+  (fn
+    (subject)
+    (reduce
+      (fn
+        (acc e)
+        (let
+          ((r (mod/get-report (get e :report-id))))
+          (if
+            (nil? r)
+            acc
+            (if
+              (if
+                (= (mod/report-about r) subject)
+                (mod/sanction? (get e :action))
+                false)
+              (+ acc 1)
+              acc))))
+      0
+      (mod/audit-all))))
+
+(define
+  mod/repeat-offender?
+  (fn (subject k) (<= k (mod/subject-sanctions subject))))
+
+(define
+  mod/decide-escalating
+  (fn
+    (id k)
+    (let
+      ((r (mod/get-report id)))
+      (if
+        (nil? r)
+        nil
+        (let
+          ((priors (mod/subject-sanctions (mod/report-about r))))
+          (let
+            ((d (mod/decide id)))
+            (if
+              (if (mod/sanction? (get d :action)) (<= k priors) false)
+              {:action "ban" :proof {:goals (get (get d :proof) :goals) :prior-sanctions priors :evidence (get (get d :proof) :evidence) :conditions (list) :rule "repeat-offender-ban" :count (get (get d :proof) :count)} :report-id id :rule "repeat-offender-ban" :strategy "escalating"}
+              d)))))))

lib/mod/pipeline.sx

@@ -0,0 +1,18 @@
+;; lib/mod/pipeline.sx — end-to-end triage orchestration.
+;;
+;; A single entry point that runs a report through the subsystem and returns the
+;; full artifact bundle: the decision (under the report's domain policy), a
+;; human-readable explanation, an ActivityPub-shaped event for the bus, and the
+;; wire line for federated peers. Composes policies (Ext 17), explain (Ext 3),
+;; activity (Ext 16) and wire (Ext 14) — the modules are independent, this is just
+;; the convenience that wires them together for the common "process a report" path.
+
+(define
+  mod/triage-pipeline
+  (fn
+    (domain r reports actor)
+    (let ((d (mod/decide-in domain r reports))) {:activity (mod/decision->activity d actor) :action (get d :action) :wire (mod/decision->wire d) :rule (get d :rule) :decision d :explanation (mod/explain d)})))
+
+(define mod/pipeline-action (fn (p) (get p :action)))
+(define mod/pipeline-activity (fn (p) (get p :activity)))
+(define mod/pipeline-wire (fn (p) (get p :wire)))

lib/mod/policies.sx

@@ -0,0 +1,40 @@
+;; lib/mod/policies.sx — per-domain policy registry.
+;;
+;; rose-ash spans domains (blog, market, events, federation, …) that want
+;; different moderation — a marketplace listing and a blog comment are not held to
+;; the same bar. This registry maps a domain to a rule set; mod/decide-in resolves
+;; the right policy and decides. Unregistered domains fall back to the default
+;; rules, so adding a domain never leaves it unmoderated.
+
+(define mod/*policies* (list))
+
+(define mod/policies-reset! (fn () (set! mod/*policies* (list))))
+
+(define
+  mod/register-policy!
+  (fn (domain rules) (begin (append! mod/*policies* {:domain domain :rules rules}) true)))
+
+(define
+  mod/policy-registered?
+  (fn
+    (domain)
+    (mod/any? (fn (p) (= (get p :domain) domain)) mod/*policies*)))
+
+(define
+  mod/policy-for
+  (fn
+    (domain)
+    (reduce
+      (fn (acc p) (if (= (get p :domain) domain) (get p :rules) acc))
+      mod/default-rules
+      mod/*policies*)))
+
+(define
+  mod/decide-in
+  (fn
+    (domain r reports)
+    (mod/decide-report r reports (mod/policy-for domain))))
+
+(define
+  mod/registered-domains
+  (fn () (map (fn (p) (get p :domain)) mod/*policies*)))

lib/mod/policy.sx

@@ -0,0 +1,137 @@
+;; lib/mod/policy.sx — moderation rules → Prolog clauses.
+;;
+;; A rule is {:name :action :when}. :when is a list of condition forms; each
+;; compiles to a Prolog goal. The conditions in a :when list are ANDed (joined by
+;; ", "); :not negates and :any (a list of sub-conditions) disjoins — so the
+;; condition language is a small boolean algebra over the leaf predicates.
+;; Rule order is precedence: the engine queries with pl-query-one, so the first
+;; clause that proves wins. The final default rule has an empty body (true) so
+;; every report yields at least :keep — "no rule matched" is a real result, not a
+;; query failure.
+;;
+;; cond->goal takes an id-term so the same condition can be compiled with the
+;; head variable "Id" (for clause bodies) or a concrete report id (for proof-tree
+;; goal-by-goal re-querying in the engine).
+;;
+;; Precedence (top wins): exoneration evidence (appeal override) > confirmed-abuse
+;; evidence (human review) > spam/abuse classification > repeated-report count >
+;; default keep.
+
+(define mod/mk-rule (fn (name action conds) {:when conds :name name :action action}))
+
+(define mod/rule-name (fn (r) (get r :name)))
+(define mod/rule-action (fn (r) (get r :action)))
+(define mod/rule-when (fn (r) (get r :when)))
+
+(define
+  mod/default-rules
+  (list
+    (mod/mk-rule
+      "exonerated-keep"
+      :keep (list (list :evidence "exonerated")))
+    (mod/mk-rule
+      "reviewer-remove"
+      :remove (list (list :evidence "confirmed-abuse")))
+    (mod/mk-rule "spam-hide" :hide (list (list :classification "spam")))
+    (mod/mk-rule
+      "abuse-remove"
+      :remove (list (list :classification "abuse")))
+    (mod/mk-rule
+      "repeated-escalate"
+      :escalate (list (list :count-at-least 3)))
+    (mod/mk-rule "default-keep" :keep (list))))
+
+;; ── condition → Prolog goal ──
+;;
+;; (:classification "spam")  → classification(Id, spam)
+;; (:evidence "kind")        → evidence(Id, 'kind', _)
+;; (:attr "verified")        → attr(Id, verified)
+;; (:not <cond>)             → not(<cond>)                        (negation)
+;; (:any (list c1 c2 ...))   → (g1 ; g2 ; ...)                    (disjunction)
+;; (:count-at-least 3)       → report(Id, B, S), report_count(S, N), N >= 3
+;; (:score-at-least 5)       → aggregate_all(sum(W), signal(Id, _, W), T), T >= 5
+;; (:reporters-at-least 2)   → report(Id, _, Sr), setof(Br, report(_, Br, Sr), Bsr),
+;;                             length(Bsr, Nr), Nr >= 2   (quorum engine)
+;; (:burst-at-least 3)       → report(Id, _, Sb), burst_count(Sb, Nb), Nb >= 3
+;;                             (temporal engine)
+
+(define
+  mod/cond->goal
+  (fn
+    (c idterm)
+    (let
+      ((tag (first c)))
+      (cond
+        ((= tag :classification)
+          (str "classification(" idterm ", " (nth c 1) ")"))
+        ((= tag :evidence)
+          (str
+            "evidence("
+            idterm
+            ", "
+            (mod/pl-quote (nth c 1))
+            ", _)"))
+        ((= tag :attr) (str "attr(" idterm ", " (nth c 1) ")"))
+        ((= tag :not)
+          (str "not(" (mod/cond->goal (nth c 1) idterm) ")"))
+        ((= tag :any)
+          (str
+            "("
+            (mod/join-with
+              " ; "
+              (map
+                (fn (sub) (mod/cond->goal sub idterm))
+                (nth c 1)))
+            ")"))
+        ((= tag :count-at-least)
+          (str
+            "report("
+            idterm
+            ", B, S), report_count(S, N), N >= "
+            (nth c 1)))
+        ((= tag :score-at-least)
+          (str
+            "aggregate_all(sum(W), signal("
+            idterm
+            ", _, W), T), T >= "
+            (nth c 1)))
+        ((= tag :reporters-at-least)
+          (str
+            "report("
+            idterm
+            ", _, Sr), setof(Br, report(_, Br, Sr), Bsr), "
+            "length(Bsr, Nr), Nr >= "
+            (nth c 1)))
+        ((= tag :burst-at-least)
+          (str
+            "report("
+            idterm
+            ", _, Sb), burst_count(Sb, Nb), Nb >= "
+            (nth c 1)))
+        (true "true")))))
+
+(define
+  mod/conds->body
+  (fn
+    (conds idterm)
+    (if
+      (empty? conds)
+      "true"
+      (mod/join-with ", " (map (fn (c) (mod/cond->goal c idterm)) conds)))))
+
+(define
+  mod/rule->clause
+  (fn
+    (r)
+    (str
+      "policy_action(Id, "
+      (mod/rule-action r)
+      ", '"
+      (mod/rule-name r)
+      "') :- "
+      (mod/conds->body (mod/rule-when r) "Id")
+      ".")))
+
+(define
+  mod/rules->program
+  (fn (rules) (mod/join-with "\n" (map mod/rule->clause rules))))

lib/mod/quorum.sx

@@ -0,0 +1,40 @@
+;; lib/mod/quorum.sx — quorum decisions over distinct reporters (anti-brigade).
+;;
+;; The base engine asserts only the decided report's report/3 fact, so it can't
+;; reason about WHO reported a subject. The quorum engine additionally asserts
+;; every report's report/3 fact (via link's rel-facts), letting a rule require N
+;; *distinct* reporters with `setof`/`length` — so one user filing many reports
+;; does not manufacture consensus. Same decision shape as the base engine, plus
+;; :strategy "quorum".
+
+(define
+  mod/build-quorum-program
+  (fn
+    (r count reports rules)
+    (str
+      (mod/report-rel-facts reports)
+      "\n"
+      (mod/report-facts r count)
+      "\n"
+      (mod/rules->program rules))))
+
+(define
+  mod/decide-quorum
+  (fn
+    (r reports rules)
+    (let
+      ((count (mod/report-count (mod/report-about r) reports))
+        (kinds (mod/classify-keywords r))
+        (id (mod/report-id r)))
+      (let
+        ((program (mod/build-quorum-program r count reports rules)))
+        (let
+          ((db (pl-load program)))
+          (let
+            ((sol (pl-query-one db (str "policy_action(" id ", Action, Rule)"))))
+            (if
+              (nil? sol)
+              {:action "keep" :proof {:goals (list) :evidence kinds :conditions (list) :rule "none" :count count} :report-id id :rule "none" :strategy "quorum"}
+              (let
+                ((rule (mod/find-rule rules (dict-get sol "Rule"))))
+                {:action (mod/rule-action rule) :proof {:goals (mod/proof-goals db id (mod/rule-when rule)) :evidence kinds :conditions (mod/rule-when rule) :rule (mod/rule-name rule) :count count} :report-id id :rule (mod/rule-name rule) :strategy "quorum"}))))))))

lib/mod/schema.sx

@@ -0,0 +1,259 @@
+;; lib/mod/schema.sx — report representation + Prolog fact generation.
+;;
+;; A report is a dict {:id :by :about :reason :evidence :attrs :signals :at}.
+;;   :evidence — accumulated {:kind :val} entries (human review, scanners)
+;;   :attrs    — attribute names ("verified") for negation-as-failure conditions
+;;   :signals  — weighted {:kind :weight} entries for aggregate scoring rules
+;;   :at       — integer timestamp/tick (deterministic; supplied, not clock-read)
+;; The engine derives keyword classifications from the reason text and projects
+;; the report, its classifications, evidence, attributes, and signals into Prolog
+;; facts that policy clauses match against.
+
+(define mod/mk-report (fn (id by about reason) {:attrs (list) :id id :signals (list) :by by :evidence (list) :about about :at 0 :reason reason}))
+
+(define mod/report-id (fn (r) (get r :id)))
+(define mod/report-by (fn (r) (get r :by)))
+(define mod/report-about (fn (r) (get r :about)))
+(define mod/report-reason (fn (r) (get r :reason)))
+
+(define
+  mod/report-evidence
+  (fn (r) (let ((e (get r :evidence))) (if (nil? e) (list) e))))
+
+(define
+  mod/report-attrs
+  (fn (r) (let ((a (get r :attrs))) (if (nil? a) (list) a))))
+
+(define
+  mod/report-signals
+  (fn (r) (let ((s (get r :signals))) (if (nil? s) (list) s))))
+
+(define
+  mod/report-at
+  (fn (r) (let ((t (get r :at))) (if (nil? t) 0 t))))
+
+(define mod/mk-evidence (fn (kind val) {:val val :kind kind}))
+(define mod/evidence-kind (fn (e) (get e :kind)))
+(define mod/evidence-val (fn (e) (get e :val)))
+
+(define mod/mk-signal (fn (kind weight) {:kind kind :weight weight}))
+(define mod/signal-kind (fn (s) (get s :kind)))
+(define mod/signal-weight (fn (s) (get s :weight)))
+
+(define mod/report* (fn (r evs attrs sigs at) {:attrs attrs :id (mod/report-id r) :signals sigs :by (mod/report-by r) :evidence evs :about (mod/report-about r) :at at :reason (mod/report-reason r)}))
+
+(define
+  mod/with-evidence
+  (fn
+    (r evs)
+    (mod/report*
+      r
+      evs
+      (mod/report-attrs r)
+      (mod/report-signals r)
+      (mod/report-at r))))
+
+(define
+  mod/with-attrs
+  (fn
+    (r attrs)
+    (mod/report*
+      r
+      (mod/report-evidence r)
+      attrs
+      (mod/report-signals r)
+      (mod/report-at r))))
+
+(define
+  mod/with-signals
+  (fn
+    (r sigs)
+    (mod/report*
+      r
+      (mod/report-evidence r)
+      (mod/report-attrs r)
+      sigs
+      (mod/report-at r))))
+
+(define
+  mod/with-at
+  (fn
+    (r at)
+    (mod/report*
+      r
+      (mod/report-evidence r)
+      (mod/report-attrs r)
+      (mod/report-signals r)
+      at)))
+
+(define
+  mod/attach-evidence
+  (fn
+    (r e)
+    (mod/with-evidence r (append (mod/report-evidence r) (list e)))))
+
+(define
+  mod/attach-attr
+  (fn (r a) (mod/with-attrs r (append (mod/report-attrs r) (list a)))))
+
+(define
+  mod/attach-signal
+  (fn (r s) (mod/with-signals r (append (mod/report-signals r) (list s)))))
+
+;; ── substring search (the prolog-loaded env lacks includes?; slice/len do work) ──
+
+(define
+  mod/contains-at?
+  (fn
+    (hay needle hl nl pos)
+    (if
+      (< hl (+ pos nl))
+      false
+      (if
+        (= (slice hay pos (+ pos nl)) needle)
+        true
+        (mod/contains-at? hay needle hl nl (+ pos 1))))))
+
+(define
+  mod/str-contains?
+  (fn
+    (hay needle)
+    (let
+      ((hl (len hay)) (nl (len needle)))
+      (if
+        (= nl 0)
+        true
+        (mod/contains-at? hay needle hl nl 0)))))
+
+;; ── evidence derivation (keyword classification) ──
+
+(define
+  mod/spam-keywords
+  (list "spam" "buy now" "click here" "free money" "viagra" "limited offer"))
+
+(define
+  mod/abuse-keywords
+  (list "abuse" "harassment" "threat" "slur" "hate speech"))
+
+(define
+  mod/any?
+  (fn (pred coll) (reduce (fn (acc x) (if acc acc (pred x))) false coll)))
+
+(define
+  mod/reason-matches?
+  (fn
+    (reason kws)
+    (let
+      ((low (downcase reason)))
+      (mod/any? (fn (k) (mod/str-contains? low k)) kws))))
+
+(define
+  mod/classify-keywords
+  (fn
+    (r)
+    (let
+      ((reason (mod/report-reason r)) (kinds (list)))
+      (begin
+        (when
+          (mod/reason-matches? reason mod/spam-keywords)
+          (append! kinds "spam"))
+        (when
+          (mod/reason-matches? reason mod/abuse-keywords)
+          (append! kinds "abuse"))
+        kinds))))
+
+(define
+  mod/report-count
+  (fn
+    (about reports)
+    (reduce
+      (fn
+        (acc r)
+        (if (= (mod/report-about r) about) (+ acc 1) acc))
+      0
+      reports)))
+
+;; ── Prolog fact projection ──
+
+(define
+  mod/join-with
+  (fn
+    (sep items)
+    (reduce (fn (acc x) (if (= acc "") x (str acc sep x))) "" items)))
+
+(define mod/pl-quote (fn (s) (str "'" s "'")))
+
+(define
+  mod/classification-facts
+  (fn
+    (id kinds)
+    (mod/join-with
+      "\n"
+      (map (fn (k) (str "classification(" id ", " k ").")) kinds))))
+
+(define
+  mod/evidence-facts
+  (fn
+    (id evs)
+    (mod/join-with
+      "\n"
+      (map
+        (fn
+          (e)
+          (str
+            "evidence("
+            id
+            ", "
+            (mod/pl-quote (mod/evidence-kind e))
+            ", "
+            (mod/pl-quote (str (mod/evidence-val e)))
+            ")."))
+        evs))))
+
+(define
+  mod/attr-facts
+  (fn
+    (id attrs)
+    (mod/join-with "\n" (map (fn (a) (str "attr(" id ", " a ").")) attrs))))
+
+(define
+  mod/signal-facts
+  (fn
+    (id sigs)
+    (mod/join-with
+      "\n"
+      (map
+        (fn
+          (s)
+          (str
+            "signal("
+            id
+            ", "
+            (mod/pl-quote (mod/signal-kind s))
+            ", "
+            (mod/signal-weight s)
+            ")."))
+        sigs))))
+
+(define
+  mod/report-facts
+  (fn
+    (r count)
+    (let
+      ((id (mod/report-id r))
+        (by (mod/pl-quote (mod/report-by r)))
+        (about (mod/pl-quote (mod/report-about r))))
+      (let
+        ((cls (mod/classification-facts id (mod/classify-keywords r)))
+          (evs (mod/evidence-facts id (mod/report-evidence r)))
+          (ats (mod/attr-facts id (mod/report-attrs r)))
+          (sgs (mod/signal-facts id (mod/report-signals r))))
+        (mod/join-with
+          "\n"
+          (list
+            (str "report(" id ", " by ", " about ").")
+            (str "report_count(" about ", " count ").")
+            cls
+            evs
+            ats
+            sgs))))))

lib/mod/scoreboard.json

@@ -0,0 +1,30 @@
+{
+  "lang": "mod",
+  "total_passed": 390,
+  "total_failed": 0,
+  "total": 390,
+  "suites": [
+    {"name":"decide","passed":31,"failed":0,"total":31},
+    {"name":"audit","passed":29,"failed":0,"total":29},
+    {"name":"escalation","passed":46,"failed":0,"total":46},
+    {"name":"fed","passed":26,"failed":0,"total":26},
+    {"name":"extensions","passed":32,"failed":0,"total":32},
+    {"name":"link","passed":12,"failed":0,"total":12},
+    {"name":"lint","passed":14,"failed":0,"total":14},
+    {"name":"severity","passed":14,"failed":0,"total":14},
+    {"name":"offenders","passed":19,"failed":0,"total":19},
+    {"name":"quorum","passed":9,"failed":0,"total":9},
+    {"name":"trace","passed":15,"failed":0,"total":15},
+    {"name":"whatif","passed":13,"failed":0,"total":13},
+    {"name":"batch","passed":17,"failed":0,"total":17},
+    {"name":"temporal","passed":15,"failed":0,"total":15},
+    {"name":"sla","passed":15,"failed":0,"total":15},
+    {"name":"wire","passed":16,"failed":0,"total":16},
+    {"name":"disjunction","passed":10,"failed":0,"total":10},
+    {"name":"activity","passed":17,"failed":0,"total":17},
+    {"name":"policies","passed":14,"failed":0,"total":14},
+    {"name":"defrule","passed":11,"failed":0,"total":11},
+    {"name":"pipeline","passed":15,"failed":0,"total":15}
+  ],
+  "generated": "2026-06-06T19:40:03+00:00"
+}

lib/mod/scoreboard.md

@@ -0,0 +1,27 @@
+# mod scoreboard
+
+**390 / 390 passing** (0 failure(s)).
+
+| Suite | Passed | Total | Status |
+|-------|--------|-------|--------|
+| decide | 31 | 31 | ok |
+| audit | 29 | 29 | ok |
+| escalation | 46 | 46 | ok |
+| fed | 26 | 26 | ok |
+| extensions | 32 | 32 | ok |
+| link | 12 | 12 | ok |
+| lint | 14 | 14 | ok |
+| severity | 14 | 14 | ok |
+| offenders | 19 | 19 | ok |
+| quorum | 9 | 9 | ok |
+| trace | 15 | 15 | ok |
+| whatif | 13 | 13 | ok |
+| batch | 17 | 17 | ok |
+| temporal | 15 | 15 | ok |
+| sla | 15 | 15 | ok |
+| wire | 16 | 16 | ok |
+| disjunction | 10 | 10 | ok |
+| activity | 17 | 17 | ok |
+| policies | 14 | 14 | ok |
+| defrule | 11 | 11 | ok |
+| pipeline | 15 | 15 | ok |

lib/mod/severity.sx

@@ -0,0 +1,60 @@
+;; lib/mod/severity.sx — "strictest-wins" decision strategy.
+;;
+;; The default engine resolves precedence by rule ORDER (first proven clause wins,
+;; via pl-query-one). Some policies instead want the HARSHEST applicable sanction
+;; regardless of order. mod/decide-strictest collects every rule that proves
+;; (pl-query-all) and picks the highest-severity action. Same decision shape as
+;; the engine, plus :strategy. Built over the engine's helpers; engine untouched.
+
+(define
+  mod/action-severity
+  (fn
+    (action)
+    (cond
+      ((= action "ban") 4)
+      ((= action "remove") 3)
+      ((= action "hide") 2)
+      ((= action "escalate") 1)
+      (true 0))))
+
+(define
+  mod/strictest-sol
+  (fn
+    (sols)
+    (reduce
+      (fn
+        (acc s)
+        (if
+          (nil? acc)
+          s
+          (if
+            (<
+              (mod/action-severity (dict-get acc "Action"))
+              (mod/action-severity (dict-get s "Action")))
+            s
+            acc)))
+      nil
+      sols)))
+
+(define
+  mod/decide-strictest
+  (fn
+    (r reports rules)
+    (let
+      ((count (mod/report-count (mod/report-about r) reports))
+        (kinds (mod/classify-keywords r))
+        (id (mod/report-id r)))
+      (let
+        ((program (mod/build-program r count rules)))
+        (let
+          ((db (pl-load program)))
+          (let
+            ((sols (pl-query-all db (str "policy_action(" id ", Action, Rule)"))))
+            (let
+              ((best (mod/strictest-sol sols)))
+              (if
+                (nil? best)
+                {:action "keep" :proof {:goals (list) :evidence kinds :conditions (list) :rule "none" :count count} :report-id id :rule "none" :strategy "strictest"}
+                (let
+                  ((rule (mod/find-rule rules (dict-get best "Rule"))))
+                  {:action (mod/rule-action rule) :proof {:goals (mod/proof-goals db id (mod/rule-when rule)) :evidence kinds :conditions (mod/rule-when rule) :rule (mod/rule-name rule) :count count} :report-id id :rule (mod/rule-name rule) :strategy "strictest"})))))))))

lib/mod/sla.sx

@@ -0,0 +1,47 @@
+;; lib/mod/sla.sx — service-level sweep over pending lifecycle cases.
+;;
+;; Composes the Phase-3 lifecycle with the Ext-12 time dimension: a case left in a
+;; pending state (open / triaged / appealed) past a deadline has breached SLA and
+;; should resurface. A timed-case pairs a case with the tick it entered its
+;; current state (the caller stamps this — the lifecycle stays timeless and pure).
+;; Terminal states (decided / final) never breach.
+
+(define mod/pending-states (list "open" "triaged" "appealed"))
+(define mod/pending-state? (fn (s) (mod/member? s mod/pending-states)))
+
+(define mod/mk-timed-case (fn (c entered-at) {:entered-at entered-at :case c}))
+(define mod/tc-case (fn (tc) (get tc :case)))
+(define mod/tc-entered-at (fn (tc) (get tc :entered-at)))
+
+(define
+  mod/overdue?
+  (fn
+    (tc now deadline)
+    (if
+      (mod/pending-state? (mod/case-state (mod/tc-case tc)))
+      (< deadline (- now (mod/tc-entered-at tc)))
+      false)))
+
+(define
+  mod/sla-sweep
+  (fn
+    (timed-cases now deadline)
+    (reduce
+      (fn
+        (acc tc)
+        (if
+          (mod/overdue? tc now deadline)
+          (append
+            acc
+            (list (mod/report-id (mod/case-report (mod/tc-case tc)))))
+          acc))
+      (list)
+      timed-cases)))
+
+(define
+  mod/overdue-count
+  (fn
+    (timed-cases now deadline)
+    (len (mod/sla-sweep timed-cases now deadline))))
+
+(define mod/age (fn (tc now) (- now (mod/tc-entered-at tc))))

lib/mod/temporal.sx

@@ -0,0 +1,62 @@
+;; lib/mod/temporal.sx — burst detection over a time window.
+;;
+;; A plain report count can't tell a burst (N reports in minutes) from slow
+;; accumulation (N reports over months). mod/decide-temporal takes a `now` tick
+;; and a `window`, counts reports about the subject with :at within [now-window,
+;; now], asserts it as burst_count/2, and lets a `(:burst-at-least K)` rule fire
+;; only on a genuine burst. Time is supplied (deterministic), never clock-read.
+
+(define
+  mod/window-count
+  (fn
+    (subject reports now window)
+    (reduce
+      (fn
+        (acc r)
+        (if
+          (if
+            (= (mod/report-about r) subject)
+            (<= (- now window) (mod/report-at r))
+            false)
+          (+ acc 1)
+          acc))
+      0
+      reports)))
+
+(define
+  mod/build-temporal-program
+  (fn
+    (r count bcount rules)
+    (str
+      (mod/report-facts r count)
+      "\n"
+      "burst_count("
+      (mod/pl-quote (mod/report-about r))
+      ", "
+      bcount
+      ").\n"
+      (mod/rules->program rules))))
+
+(define
+  mod/decide-temporal
+  (fn
+    (r reports rules now window)
+    (let
+      ((about (mod/report-about r))
+        (id (mod/report-id r))
+        (kinds (mod/classify-keywords r)))
+      (let
+        ((count (mod/report-count about reports))
+          (bcount (mod/window-count about reports now window)))
+        (let
+          ((program (mod/build-temporal-program r count bcount rules)))
+          (let
+            ((db (pl-load program)))
+            (let
+              ((sol (pl-query-one db (str "policy_action(" id ", Action, Rule)"))))
+              (if
+                (nil? sol)
+                {:action "keep" :proof {:burst bcount :goals (list) :evidence kinds :conditions (list) :rule "none" :count count} :report-id id :rule "none" :strategy "temporal"}
+                (let
+                  ((rule (mod/find-rule rules (dict-get sol "Rule"))))
+                  {:action (mod/rule-action rule) :proof {:burst bcount :goals (mod/proof-goals db id (mod/rule-when rule)) :evidence kinds :conditions (mod/rule-when rule) :rule (mod/rule-name rule) :count count} :report-id id :rule (mod/rule-name rule) :strategy "temporal"})))))))))

lib/mod/tests/activity.sx

@@ -0,0 +1,95 @@
+;; lib/mod/tests/activity.sx — Ext 16: ActivityPub-shaped decision export.
+
+(define mod-ap-count 0)
+(define mod-ap-pass 0)
+(define mod-ap-fail 0)
+(define mod-ap-failures (list))
+
+(define
+  mod-ap-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-ap-count (+ mod-ap-count 1))
+      (if
+        (= got expected)
+        (set! mod-ap-pass (+ mod-ap-pass 1))
+        (begin
+          (set! mod-ap-fail (+ mod-ap-fail 1))
+          (append!
+            mod-ap-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+;; ── action → AP verb ──
+
+(mod-ap-test! "remove → Delete" (mod/action->verb "remove") "Delete")
+(mod-ap-test! "ban → Block" (mod/action->verb "ban") "Block")
+(mod-ap-test! "hide → Flag" (mod/action->verb "hide") "Flag")
+(mod-ap-test! "escalate → Flag" (mod/action->verb "escalate") "Flag")
+(mod-ap-test! "keep → nil (no activity)" (mod/action->verb "keep") nil)
+
+;; ── single decision → activity ──
+
+(define mod-ap-spam (mod/mk-report "r1" "a" "bob" "this is spam"))
+(define
+  mod-ap-dec
+  (mod/decide-report mod-ap-spam (list mod-ap-spam) mod/default-rules))
+(define mod-ap-act (mod/decision->activity mod-ap-dec "instance.example"))
+
+(mod-ap-test! "activity type is Flag (hide)" (get mod-ap-act :type) "Flag")
+(mod-ap-test! "activity object is report id" (get mod-ap-act :object) "r1")
+(mod-ap-test!
+  "activity actor preserved"
+  (get mod-ap-act :actor)
+  "instance.example")
+(mod-ap-test!
+  "activity preserves precise action"
+  (get mod-ap-act :action)
+  "hide")
+(mod-ap-test! "activity carries rule" (get mod-ap-act :rule) "spam-hide")
+(mod-ap-test!
+  "activity summary"
+  (get mod-ap-act :summary)
+  "moderation/hide via spam-hide")
+
+;; ── keep produces no activity ──
+
+(define mod-ap-clean (mod/mk-report "r2" "a" "b" "a fine post"))
+(define
+  mod-ap-keep
+  (mod/decide-report mod-ap-clean (list mod-ap-clean) mod/default-rules))
+(mod-ap-test!
+  "keep decision → nil activity"
+  (mod/decision->activity mod-ap-keep "x")
+  nil)
+
+;; ── abuse → Delete ──
+
+(define mod-ap-abuse (mod/mk-report "r3" "a" "b" "harassment here"))
+(define
+  mod-ap-abuse-dec
+  (mod/decide-report mod-ap-abuse (list mod-ap-abuse) mod/default-rules))
+(mod-ap-test!
+  "abuse decision → Delete activity"
+  (get (mod/decision->activity mod-ap-abuse-dec "x") :type)
+  "Delete")
+
+;; ── batch export drops keeps ──
+
+(define mod-ap-decisions (list mod-ap-dec mod-ap-keep mod-ap-abuse-dec))
+(define mod-ap-acts (mod/decisions->activities mod-ap-decisions "inst"))
+(mod-ap-test! "batch export drops the keep" (len mod-ap-acts) 2)
+(mod-ap-test!
+  "batch export first is the Flag"
+  (get (first mod-ap-acts) :type)
+  "Flag")
+(mod-ap-test!
+  "batch export second is the Delete"
+  (get (nth mod-ap-acts 1) :type)
+  "Delete")
+(mod-ap-test!
+  "empty decisions → no activities"
+  (mod/decisions->activities (list) "inst")
+  (list))
+
+(define mod-activity-tests-run! (fn () {:failures mod-ap-failures :total mod-ap-count :passed mod-ap-pass :failed mod-ap-fail}))

lib/mod/tests/audit.sx

@@ -0,0 +1,187 @@
+;; lib/mod/tests/audit.sx — Phase 2: evidence accumulation + proof tree + audit.
+
+(define mod-aud-count 0)
+(define mod-aud-pass 0)
+(define mod-aud-fail 0)
+(define mod-aud-failures (list))
+
+(define
+  mod-aud-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-aud-count (+ mod-aud-count 1))
+      (if
+        (= got expected)
+        (set! mod-aud-pass (+ mod-aud-pass 1))
+        (begin
+          (set! mod-aud-fail (+ mod-aud-fail 1))
+          (append!
+            mod-aud-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+(define
+  mod-aud-decide1
+  (fn (r) (mod/decide-report r (list r) mod/default-rules)))
+
+;; ── proof tree: keyword classification ──
+
+(define
+  mod-aud-spam
+  (mod-aud-decide1 (mod/mk-report "r1" "alice" "bob" "this is spam")))
+(define mod-aud-spam-goals (get (get mod-aud-spam :proof) :goals))
+
+(mod-aud-test! "spam proof has one goal" (len mod-aud-spam-goals) 1)
+(mod-aud-test!
+  "spam proof goal text"
+  (get (first mod-aud-spam-goals) :goal)
+  "classification(r1, spam)")
+(mod-aud-test!
+  "spam proof goal solved"
+  (get (first mod-aud-spam-goals) :solved)
+  true)
+
+;; ── proof tree: count rule with real bindings ──
+
+(define mod-aud-rep-r (mod/mk-report "r3" "ann" "dave" "x"))
+(define
+  mod-aud-rep
+  (mod/decide-report
+    mod-aud-rep-r
+    (list mod-aud-rep-r mod-aud-rep-r mod-aud-rep-r)
+    mod/default-rules))
+(define mod-aud-rep-goals (get (get mod-aud-rep :proof) :goals))
+(define mod-aud-rep-binds (get (first mod-aud-rep-goals) :bindings))
+
+(mod-aud-test!
+  "count proof goal solved"
+  (get (first mod-aud-rep-goals) :solved)
+  true)
+(mod-aud-test! "count proof binding N" (dict-get mod-aud-rep-binds "N") "3")
+(mod-aud-test!
+  "count proof binding S (subject)"
+  (dict-get mod-aud-rep-binds "S")
+  "dave")
+
+;; ── proof tree: default keep has a 'true' goal ──
+
+(define
+  mod-aud-keep
+  (mod-aud-decide1 (mod/mk-report "rk" "a" "b" "a fine post")))
+(define mod-aud-keep-goals (get (get mod-aud-keep :proof) :goals))
+
+(mod-aud-test!
+  "keep proof goal text true"
+  (get (first mod-aud-keep-goals) :goal)
+  "true")
+(mod-aud-test!
+  "keep proof goal solved"
+  (get (first mod-aud-keep-goals) :solved)
+  true)
+
+;; ── evidence accumulation drives a rule ──
+
+(define
+  mod-aud-rev-r
+  (mod/attach-evidence
+    (mod/mk-report "re" "a" "carol" "neutral")
+    (mod/mk-evidence "confirmed-abuse" "human")))
+(define mod-aud-rev (mod-aud-decide1 mod-aud-rev-r))
+
+(mod-aud-test!
+  "evidence has length 1"
+  (len (mod/report-evidence mod-aud-rev-r))
+  1)
+(mod-aud-test!
+  "evidence reviewer-remove → remove"
+  (get mod-aud-rev :action)
+  "remove")
+(mod-aud-test!
+  "evidence reviewer-remove rule"
+  (get mod-aud-rev :rule)
+  "reviewer-remove")
+(mod-aud-test!
+  "evidence proof goal solved"
+  (get (first (get (get mod-aud-rev :proof) :goals)) :solved)
+  true)
+(mod-aud-test!
+  "no evidence → not reviewer-remove"
+  (get (mod-aud-decide1 (mod/mk-report "rn" "a" "b" "neutral")) :rule)
+  "default-keep")
+
+;; ── append-only audit log via the api ──
+
+(mod/reset!)
+(mod/report "alice" "bob" "this is spam")
+(mod/report "carol" "eve" "fine post")
+(define mod-aud-d1 (mod/decide "r1"))
+(define mod-aud-d2 (mod/decide "r2"))
+
+(mod-aud-test! "two decisions logged" (mod/audit-count) 2)
+(mod-aud-test!
+  "first entry seq 1"
+  (get (first (mod/audit-all)) :seq)
+  1)
+(mod-aud-test!
+  "audit r1 returns one entry"
+  (len (mod/audit "r1"))
+  1)
+(mod-aud-test!
+  "audit r1 action matches decision"
+  (get (first (mod/audit "r1")) :action)
+  (get mod-aud-d1 :action))
+(mod-aud-test!
+  "audit r1 rule matches decision"
+  (get (first (mod/audit "r1")) :rule)
+  "spam-hide")
+(mod-aud-test!
+  "audit r1 entry carries proof goals"
+  (len (get (get (first (mod/audit "r1")) :proof) :goals))
+  1)
+(mod-aud-test!
+  "audit r2 keep"
+  (get (first (mod/audit "r2")) :action)
+  "keep")
+(mod-aud-test! "audit unknown report → empty" (mod/audit "r99") (list))
+
+;; ── append-only: re-deciding appends, never mutates ──
+
+(define mod-aud-d1b (mod/decide "r1"))
+
+(mod-aud-test! "re-decide appends (count 3)" (mod/audit-count) 3)
+(mod-aud-test!
+  "audit r1 now has 2 entries"
+  (len (mod/audit "r1"))
+  2)
+(mod-aud-test!
+  "audit r1 seqs monotonic"
+  (get (nth (mod/audit "r1") 1) :seq)
+  3)
+(mod-aud-test!
+  "audit-latest r1 is seq 3"
+  (get (mod/audit-latest "r1") :seq)
+  3)
+(mod-aud-test!
+  "first r1 entry unchanged (still seq 1)"
+  (get (first (mod/audit "r1")) :seq)
+  1)
+
+;; ── evidence snapshot captured at decision time ──
+
+(mod/add-evidence "r2" "confirmed-abuse" "human")
+(define mod-aud-d2b (mod/decide "r2"))
+
+(mod-aud-test!
+  "post-evidence decision flips to remove"
+  (get mod-aud-d2b :action)
+  "remove")
+(mod-aud-test!
+  "audit snapshot records evidence kind"
+  (mod/evidence-kind (first (get (mod/audit-latest "r2") :evidence)))
+  "confirmed-abuse")
+(mod-aud-test!
+  "earlier r2 entry had empty evidence snapshot"
+  (len (get (first (mod/audit "r2")) :evidence))
+  0)
+
+(define mod-audit-tests-run! (fn () {:failures mod-aud-failures :total mod-aud-count :passed mod-aud-pass :failed mod-aud-fail}))

lib/mod/tests/batch.sx

@@ -0,0 +1,101 @@
+;; lib/mod/tests/batch.sx — Ext 11: batch triage + corpus analytics.
+
+(define mod-b-count 0)
+(define mod-b-pass 0)
+(define mod-b-fail 0)
+(define mod-b-failures (list))
+
+(define
+  mod-b-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-b-count (+ mod-b-count 1))
+      (if
+        (= got expected)
+        (set! mod-b-pass (+ mod-b-pass 1))
+        (begin
+          (set! mod-b-fail (+ mod-b-fail 1))
+          (append!
+            mod-b-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+;; corpus: 2 spam, 1 abuse, 2 clean — distinct subjects so the count rule stays quiet
+(define
+  mod-b-corpus
+  (list
+    (mod/mk-report "r1" "u" "s1" "this is spam")
+    (mod/mk-report "r2" "u" "s2" "buy now offer")
+    (mod/mk-report "r3" "u" "s3" "harassment here")
+    (mod/mk-report "r4" "u" "s4" "a fine post")
+    (mod/mk-report "r5" "u" "s5" "thanks for sharing")))
+
+(define mod-b-decisions (mod/decide-batch mod-b-corpus mod/default-rules))
+
+;; ── decide-batch ──
+
+(mod-b-test! "one decision per report" (len mod-b-decisions) 5)
+(mod-b-test!
+  "first decision is hide"
+  (get (first mod-b-decisions) :action)
+  "hide")
+
+;; ── action histogram ──
+
+(define mod-b-hist (mod/action-histogram mod-b-decisions))
+(mod-b-test! "histogram hide count" (get mod-b-hist :hide) 2)
+(mod-b-test! "histogram remove count" (get mod-b-hist :remove) 1)
+(mod-b-test! "histogram keep count" (get mod-b-hist :keep) 2)
+(mod-b-test! "histogram escalate count" (get mod-b-hist :escalate) 0)
+(mod-b-test! "histogram ban count" (get mod-b-hist :ban) 0)
+(mod-b-test!
+  "histogram totals match corpus"
+  (+
+    (+ (get mod-b-hist :hide) (get mod-b-hist :remove))
+    (+
+      (get mod-b-hist :keep)
+      (+ (get mod-b-hist :escalate) (get mod-b-hist :ban))))
+  5)
+
+;; ── rule coverage (empirical) ──
+
+(define mod-b-cov (mod/rule-coverage mod-b-corpus mod/default-rules))
+(mod-b-test! "coverage has one row per rule" (len mod-b-cov) 6)
+(mod-b-test!
+  "spam-hide fired twice"
+  (mod/rule-fire-count mod-b-decisions "spam-hide")
+  2)
+(mod-b-test!
+  "abuse-remove fired once"
+  (mod/rule-fire-count mod-b-decisions "abuse-remove")
+  1)
+(mod-b-test!
+  "default-keep fired twice"
+  (mod/rule-fire-count mod-b-decisions "default-keep")
+  2)
+
+;; ── never-fired: rules not exercised by this corpus ──
+
+(define mod-b-never (mod/never-fired mod-b-corpus mod/default-rules))
+(mod-b-test!
+  "exonerated-keep never fired"
+  (mod/member? "exonerated-keep" mod-b-never)
+  true)
+(mod-b-test!
+  "reviewer-remove never fired"
+  (mod/member? "reviewer-remove" mod-b-never)
+  true)
+(mod-b-test!
+  "repeated-escalate never fired"
+  (mod/member? "repeated-escalate" mod-b-never)
+  true)
+(mod-b-test!
+  "spam-hide DID fire (not in never-fired)"
+  (mod/member? "spam-hide" mod-b-never)
+  false)
+(mod-b-test!
+  "three rules never fired on this corpus"
+  (len mod-b-never)
+  3)
+
+(define mod-batch-tests-run! (fn () {:failures mod-b-failures :total mod-b-count :passed mod-b-pass :failed mod-b-fail}))

lib/mod/tests/decide.sx

@@ -0,0 +1,215 @@
+;; lib/mod/tests/decide.sx — Phase 1: report representation + simple policy.
+
+(define mod-dec-count 0)
+(define mod-dec-pass 0)
+(define mod-dec-fail 0)
+(define mod-dec-failures (list))
+
+(define
+  mod-dec-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-dec-count (+ mod-dec-count 1))
+      (if
+        (= got expected)
+        (set! mod-dec-pass (+ mod-dec-pass 1))
+        (begin
+          (set! mod-dec-fail (+ mod-dec-fail 1))
+          (append!
+            mod-dec-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+;; decide a single report (count over a 1-element registry)
+(define
+  mod-dec-one
+  (fn
+    (reason)
+    (let
+      ((r (mod/mk-report "r1" "alice" "bob" reason)))
+      (mod/decide-report r (list r) mod/default-rules))))
+
+(define mod-dec-action (fn (reason) (get (mod-dec-one reason) :action)))
+
+;; ── spam keyword → :hide ──
+
+(mod-dec-test!
+  "spam keyword 'spam' → hide"
+  (mod-dec-action "this is spam")
+  "hide")
+(mod-dec-test!
+  "spam keyword 'buy now' → hide"
+  (mod-dec-action "buy now while stocks last")
+  "hide")
+(mod-dec-test!
+  "spam keyword case-insensitive 'CLICK HERE' → hide"
+  (mod-dec-action "CLICK HERE now")
+  "hide")
+(mod-dec-test!
+  "spam keyword 'free money' → hide"
+  (mod-dec-action "win free money fast")
+  "hide")
+
+;; ── abuse keyword → :remove ──
+
+(mod-dec-test!
+  "abuse keyword 'harassment' → remove"
+  (mod-dec-action "ongoing harassment of users")
+  "remove")
+(mod-dec-test!
+  "abuse keyword 'threat' → remove"
+  (mod-dec-action "this is a threat")
+  "remove")
+(mod-dec-test!
+  "abuse keyword 'slur' → remove"
+  (mod-dec-action "contains a slur")
+  "remove")
+
+;; ── no rule → :keep ──
+
+(mod-dec-test!
+  "neutral reason → keep"
+  (mod-dec-action "I disagree with this post")
+  "keep")
+(mod-dec-test! "empty reason → keep" (mod-dec-action "") "keep")
+
+;; ── decision carries the matching rule (proof, not bare keyword) ──
+
+(mod-dec-test!
+  "spam decision rule name"
+  (get (mod-dec-one "this is spam") :rule)
+  "spam-hide")
+(mod-dec-test!
+  "keep decision rule name"
+  (get (mod-dec-one "fine post") :rule)
+  "default-keep")
+(mod-dec-test!
+  "abuse decision rule name"
+  (get (mod-dec-one "harassment here") :rule)
+  "abuse-remove")
+(mod-dec-test!
+  "spam proof :rule"
+  (get (get (mod-dec-one "spam!") :proof) :rule)
+  "spam-hide")
+(mod-dec-test!
+  "spam proof :evidence"
+  (get (get (mod-dec-one "spam!") :proof) :evidence)
+  (list "spam"))
+(mod-dec-test!
+  "spam proof :count"
+  (get (get (mod-dec-one "spam!") :proof) :count)
+  1)
+
+;; ── classification (evidence derivation) ──
+
+(mod-dec-test!
+  "classify spam"
+  (mod/classify-keywords (mod/mk-report "r1" "a" "b" "spam!"))
+  (list "spam"))
+(mod-dec-test!
+  "classify abuse"
+  (mod/classify-keywords (mod/mk-report "r1" "a" "b" "abuse"))
+  (list "abuse"))
+(mod-dec-test!
+  "classify neutral → empty"
+  (mod/classify-keywords (mod/mk-report "r1" "a" "b" "hello"))
+  (list))
+(mod-dec-test!
+  "classify both spam+abuse"
+  (mod/classify-keywords (mod/mk-report "r1" "a" "b" "spam and abuse"))
+  (list "spam" "abuse"))
+
+;; ── report-count + repeated → :escalate ──
+
+(define
+  mod-dec-three
+  (list
+    (mod/mk-report "r1" "a" "bob" "x")
+    (mod/mk-report "r2" "c" "bob" "y")
+    (mod/mk-report "r3" "d" "bob" "z")))
+
+(mod-dec-test!
+  "report-count counts subject"
+  (mod/report-count "bob" mod-dec-three)
+  3)
+(mod-dec-test!
+  "3 reports about subject → escalate"
+  (get
+    (mod/decide-report (first mod-dec-three) mod-dec-three mod/default-rules)
+    :action)
+  "escalate")
+(mod-dec-test!
+  "escalate rule name"
+  (get
+    (mod/decide-report (first mod-dec-three) mod-dec-three mod/default-rules)
+    :rule)
+  "repeated-escalate")
+
+(define
+  mod-dec-two
+  (list
+    (mod/mk-report "r1" "a" "carol" "x")
+    (mod/mk-report "r2" "c" "carol" "y")))
+
+(mod-dec-test!
+  "2 reports about subject → keep (below threshold)"
+  (get
+    (mod/decide-report (first mod-dec-two) mod-dec-two mod/default-rules)
+    :action)
+  "keep")
+
+;; ── precedence: spam beats repeated ──
+
+(define
+  mod-dec-spam-among-many
+  (list
+    (mod/mk-report "r1" "a" "dave" "buy now spam")
+    (mod/mk-report "r2" "c" "dave" "y")
+    (mod/mk-report "r3" "d" "dave" "z")))
+
+(mod-dec-test!
+  "spam wins over repeated (precedence)"
+  (get
+    (mod/decide-report
+      (first mod-dec-spam-among-many)
+      mod-dec-spam-among-many
+      mod/default-rules)
+    :action)
+  "hide")
+
+;; ── accessors ──
+
+(mod-dec-test!
+  "report-about accessor"
+  (mod/report-about (mod/mk-report "r1" "a" "bob" "x"))
+  "bob")
+(mod-dec-test!
+  "report-by accessor"
+  (mod/report-by (mod/mk-report "r1" "alice" "bob" "x"))
+  "alice")
+
+;; ── api registry ──
+
+(mod/reset!)
+(define mod-dec-r1 (mod/report "alice" "bob" "this is spam"))
+(define mod-dec-r2 (mod/report "carol" "eve" "fine post"))
+
+(mod-dec-test!
+  "mod/report assigns sequential id r1"
+  (mod/report-id mod-dec-r1)
+  "r1")
+(mod-dec-test!
+  "mod/report assigns sequential id r2"
+  (mod/report-id mod-dec-r2)
+  "r2")
+(mod-dec-test!
+  "mod/decide via registry → hide"
+  (get (mod/decide "r1") :action)
+  "hide")
+(mod-dec-test!
+  "mod/decide via registry → keep"
+  (get (mod/decide "r2") :action)
+  "keep")
+(mod-dec-test! "mod/decide unknown id → nil" (mod/decide "r99") nil)
+
+(define mod-decide-tests-run! (fn () {:failures mod-dec-failures :total mod-dec-count :passed mod-dec-pass :failed mod-dec-fail}))

lib/mod/tests/defrule.sx

@@ -0,0 +1,95 @@
+;; lib/mod/tests/defrule.sx — Ext 18: ergonomic defrule / ruleset.
+
+(define mod-dr-count 0)
+(define mod-dr-pass 0)
+(define mod-dr-fail 0)
+(define mod-dr-failures (list))
+
+(define
+  mod-dr-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-dr-count (+ mod-dr-count 1))
+      (if
+        (= got expected)
+        (set! mod-dr-pass (+ mod-dr-pass 1))
+        (begin
+          (set! mod-dr-fail (+ mod-dr-fail 1))
+          (append!
+            mod-dr-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+;; ── defrule produces the same structure as mk-rule ──
+
+(define
+  mod-dr-r
+  (mod/defrule "spam-hide" :hide (list :classification "spam")))
+(mod-dr-test! "defrule name" (mod/rule-name mod-dr-r) "spam-hide")
+(mod-dr-test! "defrule action" (mod/rule-action mod-dr-r) "hide")
+(mod-dr-test!
+  "defrule when wraps the conditions"
+  (mod/rule-when mod-dr-r)
+  (list (list :classification "spam")))
+(mod-dr-test!
+  "defrule equals mk-rule equivalent"
+  (mod/rule-when mod-dr-r)
+  (mod/rule-when
+    (mod/mk-rule "spam-hide" :hide (list (list :classification "spam")))))
+
+;; ── multi-condition + no-condition ──
+
+(define
+  mod-dr-multi
+  (mod/defrule
+    "strict"
+    :hide (list :classification "spam")
+    (list :not (list :attr "verified"))))
+(mod-dr-test!
+  "defrule collects multiple conditions"
+  (len (mod/rule-when mod-dr-multi))
+  2)
+
+(define mod-dr-catch (mod/defrule "default-keep" :keep))
+(mod-dr-test!
+  "defrule with no conditions is unconditional"
+  (mod/rule-when mod-dr-catch)
+  (list))
+
+;; ── ruleset assembles a list ──
+
+(define
+  mod-dr-rules
+  (mod/ruleset
+    (mod/defrule "spam-hide" :hide (list :classification "spam"))
+    (mod/defrule "default-keep" :keep)))
+
+(mod-dr-test! "ruleset length" (len mod-dr-rules) 2)
+(mod-dr-test!
+  "ruleset first rule name"
+  (mod/rule-name (first mod-dr-rules))
+  "spam-hide")
+
+;; ── engine works with defrule/ruleset-built policy ──
+
+(define mod-dr-spam (mod/mk-report "r1" "a" "b" "this is spam"))
+(define mod-dr-clean (mod/mk-report "r2" "a" "b" "a fine post"))
+
+(mod-dr-test!
+  "defrule policy: spam → hide"
+  (get
+    (mod/decide-report mod-dr-spam (list mod-dr-spam) mod-dr-rules)
+    :action)
+  "hide")
+(mod-dr-test!
+  "defrule policy: clean → keep"
+  (get
+    (mod/decide-report mod-dr-clean (list mod-dr-clean) mod-dr-rules)
+    :action)
+  "keep")
+(mod-dr-test!
+  "defrule policy: spam names the rule"
+  (get (mod/decide-report mod-dr-spam (list mod-dr-spam) mod-dr-rules) :rule)
+  "spam-hide")
+
+(define mod-defrule-tests-run! (fn () {:failures mod-dr-failures :total mod-dr-count :passed mod-dr-pass :failed mod-dr-fail}))

lib/mod/tests/disjunction.sx

@@ -0,0 +1,145 @@
+;; lib/mod/tests/disjunction.sx — Ext 15: disjunctive (:any) conditions.
+
+(define mod-or-count 0)
+(define mod-or-pass 0)
+(define mod-or-fail 0)
+(define mod-or-failures (list))
+
+(define
+  mod-or-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-or-count (+ mod-or-count 1))
+      (if
+        (= got expected)
+        (set! mod-or-pass (+ mod-or-pass 1))
+        (begin
+          (set! mod-or-fail (+ mod-or-fail 1))
+          (append!
+            mod-or-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+;; one rule, OR of two classifications → one action covers both
+(define
+  mod-or-rules
+  (list
+    (mod/mk-rule
+      "spam-or-abuse-hide"
+      :hide (list
+        (list
+          :any (list (list :classification "spam") (list :classification "abuse")))))
+    (mod/mk-rule "default-keep" :keep (list))))
+
+(define mod-or-spam (mod/mk-report "r1" "a" "b" "this is spam"))
+(define mod-or-abuse (mod/mk-report "r2" "a" "b" "harassment here"))
+(define mod-or-clean (mod/mk-report "r3" "a" "b" "a fine post"))
+
+(mod-or-test!
+  "OR: spam branch → hide"
+  (get
+    (mod/decide-report mod-or-spam (list mod-or-spam) mod-or-rules)
+    :action)
+  "hide")
+(mod-or-test!
+  "OR: abuse branch → hide"
+  (get
+    (mod/decide-report mod-or-abuse (list mod-or-abuse) mod-or-rules)
+    :action)
+  "hide")
+(mod-or-test!
+  "OR: neither branch → keep"
+  (get
+    (mod/decide-report mod-or-clean (list mod-or-clean) mod-or-rules)
+    :action)
+  "keep")
+
+;; ── goal text + proof ──
+
+(mod-or-test!
+  "cond->goal :any joins with ;"
+  (mod/cond->goal
+    (list
+      :any (list (list :classification "spam") (list :classification "abuse")))
+    "Id")
+  "(classification(Id, spam) ; classification(Id, abuse))")
+
+(define
+  mod-or-dec
+  (mod/decide-report mod-or-spam (list mod-or-spam) mod-or-rules))
+(mod-or-test!
+  "OR proof goal solved"
+  (get (first (get (get mod-or-dec :proof) :goals)) :solved)
+  true)
+(mod-or-test!
+  "OR proof goal text"
+  (get (first (get (get mod-or-dec :proof) :goals)) :goal)
+  "(classification(r1, spam) ; classification(r1, abuse))")
+
+;; ── :any composes with :not (NOR-ish) and :attr ──
+
+(define
+  mod-or-mixed-rules
+  (list
+    (mod/mk-rule
+      "spam-or-flagged-hide"
+      :hide (list
+        (list
+          :any (list (list :classification "spam") (list :attr "flagged")))))
+    (mod/mk-rule "default-keep" :keep (list))))
+
+(define
+  mod-or-flagged
+  (mod/attach-attr (mod/mk-report "r4" "a" "b" "a fine post") "flagged"))
+(mod-or-test!
+  "OR over classification|attr: flagged clean post → hide"
+  (get
+    (mod/decide-report
+      mod-or-flagged
+      (list mod-or-flagged)
+      mod-or-mixed-rules)
+    :action)
+  "hide")
+
+(mod-or-test!
+  "cond->goal :any with :not branch"
+  (mod/cond->goal
+    (list
+      :any (list
+        (list :classification "spam")
+        (list :not (list :attr "verified"))))
+    "Id")
+  "(classification(Id, spam) ; not(attr(Id, verified)))")
+
+;; AND still works alongside OR in the same :when list
+(define
+  mod-or-and-rules
+  (list
+    (mod/mk-rule
+      "spam-and-not-verified"
+      :hide (list
+        (list
+          :any (list (list :classification "spam") (list :classification "abuse")))
+        (list :not (list :attr "verified"))))
+    (mod/mk-rule "default-keep" :keep (list))))
+
+(define
+  mod-or-spam-verified
+  (mod/attach-attr (mod/mk-report "r5" "a" "b" "this is spam") "verified"))
+(mod-or-test!
+  "AND of OR + NOT: verified spam → keep"
+  (get
+    (mod/decide-report
+      mod-or-spam-verified
+      (list mod-or-spam-verified)
+      mod-or-and-rules)
+    :action)
+  "keep")
+(mod-or-test!
+  "AND of OR + NOT: unverified abuse → hide"
+  (get
+    (mod/decide-report mod-or-abuse (list mod-or-abuse) mod-or-and-rules)
+    :action)
+  "hide")
+
+(define mod-disjunction-tests-run! (fn () {:failures mod-or-failures :total mod-or-count :passed mod-or-pass :failed mod-or-fail}))

lib/mod/tests/escalation.sx

@@ -0,0 +1,279 @@
+;; lib/mod/tests/escalation.sx — Phase 3: lifecycle state machine + escalation.
+
+(define mod-esc-count 0)
+(define mod-esc-pass 0)
+(define mod-esc-fail 0)
+(define mod-esc-failures (list))
+
+(define
+  mod-esc-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-esc-count (+ mod-esc-count 1))
+      (if
+        (= got expected)
+        (set! mod-esc-pass (+ mod-esc-pass 1))
+        (begin
+          (set! mod-esc-fail (+ mod-esc-fail 1))
+          (append!
+            mod-esc-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+;; ── transition table guard ──
+
+(mod-esc-test!
+  "open → triaged allowed"
+  (mod/lc-can-transition? "open" "triaged")
+  true)
+(mod-esc-test!
+  "triaged → decided allowed"
+  (mod/lc-can-transition? "triaged" "decided")
+  true)
+(mod-esc-test!
+  "decided → appealed allowed"
+  (mod/lc-can-transition? "decided" "appealed")
+  true)
+(mod-esc-test!
+  "appealed → final allowed"
+  (mod/lc-can-transition? "appealed" "final")
+  true)
+(mod-esc-test!
+  "open → decided rejected"
+  (mod/lc-can-transition? "open" "decided")
+  false)
+(mod-esc-test!
+  "triaged → final rejected"
+  (mod/lc-can-transition? "triaged" "final")
+  false)
+(mod-esc-test!
+  "final is terminal"
+  (mod/lc-can-transition? "final" "open")
+  false)
+
+;; ── initial state ──
+
+(define
+  mod-esc-c0
+  (mod/mk-case (mod/mk-report "r1" "alice" "bob" "this is spam")))
+(mod-esc-test! "new case is open" (mod/case-state mod-esc-c0) "open")
+(mod-esc-test! "new case has no decision" (mod/case-decision mod-esc-c0) nil)
+
+;; ── auto-tier: spam triages + resolves to decided/hide ──
+
+(define
+  mod-esc-spam-rep
+  (list (mod/mk-report "r1" "alice" "bob" "this is spam")))
+(define
+  mod-esc-t1
+  (mod/case-triage mod-esc-c0 mod-esc-spam-rep mod/default-rules))
+(mod-esc-test! "spam triaged" (mod/case-state mod-esc-t1) "triaged")
+(mod-esc-test! "spam triage tier auto" (mod/case-tier mod-esc-t1) "auto")
+(mod-esc-test! "spam triage action hide" (mod/case-action mod-esc-t1) "hide")
+
+(define mod-esc-r1 (mod/case-resolve mod-esc-t1))
+(mod-esc-test!
+  "auto resolve → decided"
+  (mod/case-state mod-esc-r1)
+  "decided")
+(mod-esc-test!
+  "decision preserved through resolve"
+  (mod/case-action mod-esc-r1)
+  "hide")
+
+;; ── illegal transition flags :error, leaves state ──
+
+(define mod-esc-bad (mod/case-finalize mod-esc-c0))
+(mod-esc-test!
+  "finalize from open is illegal"
+  (mod/case-state mod-esc-bad)
+  "open")
+(mod-esc-test!
+  "illegal transition sets error"
+  (nil? (mod/case-error mod-esc-bad))
+  false)
+
+;; ── human-tier: repeated report escalates, resolve blocked, review decides ──
+
+(define mod-esc-rep-r (mod/mk-report "r3" "ann" "dave" "off-topic"))
+(define mod-esc-rep-reports (list mod-esc-rep-r mod-esc-rep-r mod-esc-rep-r))
+(define mod-esc-rep-c0 (mod/mk-case mod-esc-rep-r))
+(define
+  mod-esc-rep-t
+  (mod/case-triage mod-esc-rep-c0 mod-esc-rep-reports mod/default-rules))
+
+(mod-esc-test!
+  "repeated triage action escalate"
+  (mod/case-action mod-esc-rep-t)
+  "escalate")
+(mod-esc-test!
+  "repeated triage tier human"
+  (mod/case-tier mod-esc-rep-t)
+  "human")
+(mod-esc-test!
+  "repeated still triaged after triage"
+  (mod/case-state mod-esc-rep-t)
+  "triaged")
+
+(define mod-esc-rep-block (mod/case-resolve mod-esc-rep-t))
+(mod-esc-test!
+  "auto-resolve blocked on human tier (state unchanged)"
+  (mod/case-state mod-esc-rep-block)
+  "triaged")
+(mod-esc-test!
+  "blocked resolve sets error"
+  (nil? (mod/case-error mod-esc-rep-block))
+  false)
+
+(define
+  mod-esc-rep-rev
+  (mod/case-review
+    mod-esc-rep-t
+    "confirmed-abuse"
+    "human"
+    mod-esc-rep-reports
+    mod/default-rules))
+(mod-esc-test!
+  "human review → decided"
+  (mod/case-state mod-esc-rep-rev)
+  "decided")
+(mod-esc-test!
+  "human review action remove"
+  (mod/case-action mod-esc-rep-rev)
+  "remove")
+(mod-esc-test!
+  "review attached evidence to report"
+  (len (mod/report-evidence (mod/case-report mod-esc-rep-rev)))
+  1)
+
+(define mod-esc-rep-final (mod/case-finalize mod-esc-rep-rev))
+(mod-esc-test!
+  "review case finalizes"
+  (mod/case-state mod-esc-rep-final)
+  "final")
+
+;; ── appeal overrides a prior decision ──
+
+(define
+  mod-esc-ap-c0
+  (mod/mk-case (mod/mk-report "r5" "u" "v" "buy now spam")))
+(define mod-esc-ap-rep (list (mod/mk-report "r5" "u" "v" "buy now spam")))
+(define
+  mod-esc-ap-t
+  (mod/case-triage mod-esc-ap-c0 mod-esc-ap-rep mod/default-rules))
+(define mod-esc-ap-d (mod/case-resolve mod-esc-ap-t))
+
+(mod-esc-test!
+  "appeal precondition decided/hide"
+  (mod/case-action mod-esc-ap-d)
+  "hide")
+
+(define
+  mod-esc-ap-appealed
+  (mod/case-appeal
+    mod-esc-ap-d
+    "exonerated"
+    "moderator"
+    mod-esc-ap-rep
+    mod/default-rules))
+(mod-esc-test!
+  "appeal → appealed state"
+  (mod/case-state mod-esc-ap-appealed)
+  "appealed")
+(mod-esc-test!
+  "appeal overrides hide → keep"
+  (mod/case-action mod-esc-ap-appealed)
+  "keep")
+(mod-esc-test!
+  "appeal recorded via exonerated-keep rule"
+  (get (mod/case-decision mod-esc-ap-appealed) :rule)
+  "exonerated-keep")
+
+(define mod-esc-ap-final (mod/case-finalize mod-esc-ap-appealed))
+(mod-esc-test! "appealed → final" (mod/case-state mod-esc-ap-final) "final")
+
+;; ── history records the full traversal ──
+
+(mod-esc-test!
+  "full lifecycle history length 4 (triage,resolve,appeal,finalize)"
+  (len (mod/case-history mod-esc-ap-final))
+  4)
+(mod-esc-test!
+  "first history step open→triaged"
+  (get (first (mod/case-history mod-esc-ap-final)) :to)
+  "triaged")
+(mod-esc-test!
+  "last history step → final"
+  (get (nth (mod/case-history mod-esc-ap-final) 3) :to)
+  "final")
+
+;; ── api-level lifecycle façade ──
+
+(mod/reset!)
+(mod/report "alice" "bob" "this is spam")
+(mod/report "carol" "dave" "off-topic")
+(mod/report "carol" "dave" "off-topic")
+(mod/report "carol" "dave" "off-topic")
+
+(mod-esc-test!
+  "api: case opens at open"
+  (mod/case-state (mod/case-of "r1"))
+  "open")
+
+(define mod-esc-api-t1 (mod/triage "r1"))
+(mod-esc-test!
+  "api: triage spam → triaged"
+  (mod/case-state mod-esc-api-t1)
+  "triaged")
+(mod-esc-test!
+  "api: triage spam action hide"
+  (mod/case-action mod-esc-api-t1)
+  "hide")
+
+(define mod-esc-api-r1 (mod/resolve "r1"))
+(mod-esc-test!
+  "api: resolve → decided"
+  (mod/case-state mod-esc-api-r1)
+  "decided")
+(mod-esc-test!
+  "api: resolve logged decision"
+  (len (mod/audit "r1"))
+  1)
+
+(define mod-esc-api-app (mod/appeal "r1" "exonerated" "mod"))
+(mod-esc-test!
+  "api: appeal → appealed"
+  (mod/case-state mod-esc-api-app)
+  "appealed")
+(mod-esc-test!
+  "api: appeal overrides → keep"
+  (mod/case-action mod-esc-api-app)
+  "keep")
+(mod-esc-test!
+  "api: appeal logged second decision"
+  (len (mod/audit "r1"))
+  2)
+(mod-esc-test!
+  "api: finalize → final"
+  (mod/case-state (mod/finalize "r1"))
+  "final")
+
+;; r4 is the 3rd report about dave → escalates via the human tier
+(define mod-esc-api-t4 (mod/triage "r4"))
+(mod-esc-test!
+  "api: repeated triage escalates (human tier)"
+  (mod/case-tier mod-esc-api-t4)
+  "human")
+(define mod-esc-api-blk (mod/resolve "r4"))
+(mod-esc-test!
+  "api: escalated resolve blocked"
+  (mod/case-state mod-esc-api-blk)
+  "triaged")
+(define mod-esc-api-rev (mod/review "r4" "confirmed-abuse" "human"))
+(mod-esc-test!
+  "api: review → decided/remove"
+  (mod/case-action mod-esc-api-rev)
+  "remove")
+(mod-esc-test! "api: unknown id → nil" (mod/triage "r99") nil)
+
+(define mod-escalation-tests-run! (fn () {:failures mod-esc-failures :total mod-esc-count :passed mod-esc-pass :failed mod-esc-fail}))

lib/mod/tests/extensions.sx

@@ -0,0 +1,313 @@
+;; lib/mod/tests/extensions.sx — beyond-roadmap extensions.
+;;
+;; Ext 1: negation-as-failure conditions (:not / :attr) + report attributes.
+;;        "hide spam UNLESS the author is verified" (closed-world reasoning).
+;; Ext 2: weighted/aggregate evidence scoring (:score-at-least) + report signals.
+;;        Many low-confidence signals accumulate past a threshold via Prolog
+;;        aggregate_all(sum(W), ...).
+;; Ext 3: human-readable proof explanation (mod/explain) over the proof tree.
+;; Demonstrated with custom rule sets so the default policy (and its conformance
+;; tests) stays untouched.
+
+(define mod-ext-count 0)
+(define mod-ext-pass 0)
+(define mod-ext-fail 0)
+(define mod-ext-failures (list))
+
+(define
+  mod-ext-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-ext-count (+ mod-ext-count 1))
+      (if
+        (= got expected)
+        (set! mod-ext-pass (+ mod-ext-pass 1))
+        (begin
+          (set! mod-ext-fail (+ mod-ext-fail 1))
+          (append!
+            mod-ext-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+;; ── Ext 1: report attributes ──
+
+(define mod-ext-r0 (mod/mk-report "r1" "a" "b" "this is spam"))
+(mod-ext-test!
+  "fresh report has no attrs"
+  (len (mod/report-attrs mod-ext-r0))
+  0)
+(define mod-ext-rv (mod/attach-attr mod-ext-r0 "verified"))
+(mod-ext-test!
+  "attach-attr adds one attr"
+  (len (mod/report-attrs mod-ext-rv))
+  1)
+(mod-ext-test!
+  "attach-attr preserves evidence field"
+  (len
+    (mod/report-evidence
+      (mod/attach-evidence mod-ext-rv (mod/mk-evidence "x" "y"))))
+  1)
+(mod-ext-test!
+  "attach-evidence preserves attrs"
+  (len
+    (mod/report-attrs
+      (mod/attach-evidence mod-ext-rv (mod/mk-evidence "x" "y"))))
+  1)
+
+;; ── Ext 1: negation-as-failure: spam hidden unless author verified ──
+
+(define
+  mod-ext-rules
+  (list
+    (mod/mk-rule
+      "spam-unverified-hide"
+      :hide (list
+        (list :classification "spam")
+        (list :not (list :attr "verified"))))
+    (mod/mk-rule "default-keep" :keep (list))))
+
+(define mod-ext-spam-plain (mod/mk-report "p1" "a" "b" "this is spam"))
+(define
+  mod-ext-spam-verified
+  (mod/attach-attr (mod/mk-report "p2" "a" "b" "this is spam") "verified"))
+(define mod-ext-clean (mod/mk-report "p3" "a" "b" "a fine post"))
+
+(mod-ext-test!
+  "unverified spam → hide"
+  (get
+    (mod/decide-report
+      mod-ext-spam-plain
+      (list mod-ext-spam-plain)
+      mod-ext-rules)
+    :action)
+  "hide")
+(mod-ext-test!
+  "verified author spam → keep (negation blocks)"
+  (get
+    (mod/decide-report
+      mod-ext-spam-verified
+      (list mod-ext-spam-verified)
+      mod-ext-rules)
+    :action)
+  "keep")
+(mod-ext-test!
+  "clean post → keep"
+  (get
+    (mod/decide-report mod-ext-clean (list mod-ext-clean) mod-ext-rules)
+    :action)
+  "keep")
+
+;; ── Ext 1: negation appears in the goal text + proof ──
+
+(define
+  mod-ext-dec
+  (mod/decide-report
+    mod-ext-spam-plain
+    (list mod-ext-spam-plain)
+    mod-ext-rules))
+(define mod-ext-goals (get (get mod-ext-dec :proof) :goals))
+
+(mod-ext-test!
+  "rule that matched is spam-unverified-hide"
+  (get mod-ext-dec :rule)
+  "spam-unverified-hide")
+(mod-ext-test! "proof has two goals" (len mod-ext-goals) 2)
+(mod-ext-test!
+  "negation goal text"
+  (get (nth mod-ext-goals 1) :goal)
+  "not(attr(p1, verified))")
+(mod-ext-test!
+  "negation goal solved for unverified"
+  (get (nth mod-ext-goals 1) :solved)
+  true)
+
+;; ── Ext 1: cond->goal compiles :attr and :not directly ──
+
+(mod-ext-test!
+  "cond->goal :attr"
+  (mod/cond->goal (list :attr "verified") "Id")
+  "attr(Id, verified)")
+(mod-ext-test!
+  "cond->goal :not wraps inner"
+  (mod/cond->goal (list :not (list :classification "spam")) "Id")
+  "not(classification(Id, spam))")
+
+;; ── Ext 1: positive :attr condition (allowlist-style) ──
+
+(define
+  mod-ext-allow-rules
+  (list
+    (mod/mk-rule "trusted-keep" :keep (list (list :attr "trusted")))
+    (mod/mk-rule "spam-hide" :hide (list (list :classification "spam")))
+    (mod/mk-rule "default-keep" :keep (list))))
+
+(define
+  mod-ext-trusted-spam
+  (mod/attach-attr (mod/mk-report "t1" "a" "b" "this is spam") "trusted"))
+(mod-ext-test!
+  "trusted attr exempts spam → keep"
+  (get
+    (mod/decide-report
+      mod-ext-trusted-spam
+      (list mod-ext-trusted-spam)
+      mod-ext-allow-rules)
+    :action)
+  "keep")
+
+;; ── Ext 2: weighted signals + aggregate scoring ──
+
+(define mod-ext-s0 (mod/mk-report "s1" "a" "b" "neutral"))
+(mod-ext-test!
+  "fresh report has no signals"
+  (len (mod/report-signals mod-ext-s0))
+  0)
+(define
+  mod-ext-s1
+  (mod/attach-signal mod-ext-s0 (mod/mk-signal "link" 2)))
+(mod-ext-test!
+  "attach-signal adds one"
+  (len (mod/report-signals mod-ext-s1))
+  1)
+(mod-ext-test!
+  "attach-signal preserves attrs"
+  (len
+    (mod/report-attrs
+      (mod/attach-signal mod-ext-rv (mod/mk-signal "x" 1))))
+  1)
+
+(define
+  mod-ext-score-rules
+  (list
+    (mod/mk-rule
+      "high-score-hide"
+      :hide (list (list :score-at-least 5)))
+    (mod/mk-rule "default-keep" :keep (list))))
+
+;; one weak signal (2) — below threshold
+(define
+  mod-ext-weak
+  (mod/attach-signal
+    (mod/mk-report "w1" "a" "b" "neutral")
+    (mod/mk-signal "link" 2)))
+(mod-ext-test!
+  "single weak signal → keep (below threshold)"
+  (get
+    (mod/decide-report mod-ext-weak (list mod-ext-weak) mod-ext-score-rules)
+    :action)
+  "keep")
+
+;; three signals summing to 6 — over threshold
+(define
+  mod-ext-strong0
+  (mod/attach-signal
+    (mod/mk-report "w2" "a" "b" "neutral")
+    (mod/mk-signal "link" 2)))
+(define
+  mod-ext-strong1
+  (mod/attach-signal mod-ext-strong0 (mod/mk-signal "newaccount" 2)))
+(define
+  mod-ext-strong
+  (mod/attach-signal mod-ext-strong1 (mod/mk-signal "burst" 2)))
+(mod-ext-test!
+  "accumulated signals (2+2+2=6) → hide"
+  (get
+    (mod/decide-report
+      mod-ext-strong
+      (list mod-ext-strong)
+      mod-ext-score-rules)
+    :action)
+  "hide")
+(mod-ext-test!
+  "scoring rule named in decision"
+  (get
+    (mod/decide-report
+      mod-ext-strong
+      (list mod-ext-strong)
+      mod-ext-score-rules)
+    :rule)
+  "high-score-hide")
+
+;; exactly at threshold (5) fires
+(define
+  mod-ext-exact0
+  (mod/attach-signal
+    (mod/mk-report "w3" "a" "b" "neutral")
+    (mod/mk-signal "link" 3)))
+(define
+  mod-ext-exact
+  (mod/attach-signal mod-ext-exact0 (mod/mk-signal "burst" 2)))
+(mod-ext-test!
+  "exactly at threshold (5) → hide"
+  (get
+    (mod/decide-report mod-ext-exact (list mod-ext-exact) mod-ext-score-rules)
+    :action)
+  "hide")
+
+(mod-ext-test!
+  "cond->goal :score-at-least"
+  (mod/cond->goal (list :score-at-least 5) "Id")
+  "aggregate_all(sum(W), signal(Id, _, W), T), T >= 5")
+
+;; ── Ext 3: human-readable proof explanation ──
+
+(define mod-ext-spam-explain (mod/explain mod-ext-dec))
+
+(mod-ext-test!
+  "explain mentions the report id"
+  (mod/str-contains? mod-ext-spam-explain "Report p1")
+  true)
+(mod-ext-test!
+  "explain mentions the action"
+  (mod/str-contains? mod-ext-spam-explain "hide")
+  true)
+(mod-ext-test!
+  "explain mentions the rule"
+  (mod/str-contains? mod-ext-spam-explain "spam-unverified-hide")
+  true)
+(mod-ext-test!
+  "explain marks proved goals"
+  (mod/str-contains? mod-ext-spam-explain "[proved]")
+  true)
+(mod-ext-test!
+  "explain renders the evidence line"
+  (mod/str-contains? mod-ext-spam-explain "Evidence: spam")
+  true)
+
+;; count-rule explanation shows the unification bindings
+(define mod-ext-rep-r (mod/mk-report "rc" "ann" "dave" "off-topic"))
+(define
+  mod-ext-rep-d
+  (mod/decide-report
+    mod-ext-rep-r
+    (list mod-ext-rep-r mod-ext-rep-r mod-ext-rep-r)
+    mod/default-rules))
+(define mod-ext-rep-explain (mod/explain mod-ext-rep-d))
+(mod-ext-test!
+  "explain shows binding N=3"
+  (mod/str-contains? mod-ext-rep-explain "N=3")
+  true)
+(mod-ext-test!
+  "explain shows subject binding"
+  (mod/str-contains? mod-ext-rep-explain "dave")
+  true)
+
+;; explain-goal direct: unproved goal gets [unproved]
+(mod-ext-test!
+  "explain-goal marks unproved"
+  (mod/str-contains? (mod/explain-goal {:solved false :goal "attr(x, foo)" :bindings {}}) "[unproved]")
+  true)
+;; explain-binds renders key=value pairs
+(mod-ext-test!
+  "explain-binds renders pair"
+  (mod/explain-binds {:N "3"})
+  "N=3")
+;; no-evidence decision says (none)
+(define
+  mod-ext-keep-d
+  (mod/decide-report mod-ext-clean (list mod-ext-clean) mod-ext-rules))
+(mod-ext-test!
+  "explain (none) for empty evidence"
+  (mod/str-contains? (mod/explain mod-ext-keep-d) "Evidence: (none)")
+  true)
+
+(define mod-extensions-tests-run! (fn () {:failures mod-ext-failures :total mod-ext-count :passed mod-ext-pass :failed mod-ext-fail}))

lib/mod/tests/fed.sx

@@ -0,0 +1,154 @@
+;; lib/mod/tests/fed.sx — Phase 4: federation (mock fed-sx).
+
+(define mod-fed-count 0)
+(define mod-fed-pass 0)
+(define mod-fed-fail 0)
+(define mod-fed-failures (list))
+
+(define
+  mod-fed-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-fed-count (+ mod-fed-count 1))
+      (if
+        (= got expected)
+        (set! mod-fed-pass (+ mod-fed-pass 1))
+        (begin
+          (set! mod-fed-fail (+ mod-fed-fail 1))
+          (append!
+            mod-fed-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+(mod/reset!)
+(mod/fed-reset!)
+
+;; ── trust model (advisory by default) ──
+
+(mod-fed-test! "trust initially false" (mod/trusted? "peerA" :mod) false)
+(mod/grant-trust "peerA" :mod)
+(mod-fed-test! "trust after grant" (mod/trusted? "peerA" :mod) true)
+(mod-fed-test! "trust wrong scope" (mod/trusted? "peerA" :other) false)
+(mod-fed-test! "trust other peer" (mod/trusted? "peerB" :mod) false)
+(mod/revoke-trust "peerA" :mod)
+(mod-fed-test! "trust after revoke" (mod/trusted? "peerA" :mod) false)
+
+;; ── cross-instance reports ──
+
+(define
+  mod-fed-fr
+  (mod/fed-receive-report "peerB" "alice" "bob" "this is spam"))
+(mod-fed-test! "fed report assigned id r1" (mod/report-id mod-fed-fr) "r1")
+(mod-fed-test! "fed report origin is peer" (mod/report-origin "r1") "peerB")
+(define mod-fed-local (mod/report "carol" "dave" "fine post"))
+(mod-fed-test!
+  "local report origin is local"
+  (mod/report-origin (mod/report-id mod-fed-local))
+  "local")
+(mod-fed-test!
+  "engine decides fed report (spam → hide)"
+  (get
+    (mod/decide-report mod-fed-fr (list mod-fed-fr) mod/default-rules)
+    :action)
+  "hide")
+
+;; ── decision sharing (outbox) ──
+
+(define mod-fed-dec {:action "hide" :rule "spam-hide" :report-id "r1"})
+(define
+  mod-fed-shared
+  (mod/fed-share-decision mod-fed-dec (list "peerB" "peerC")))
+(mod-fed-test! "share returns notified peers" (len mod-fed-shared) 2)
+(mod-fed-test! "outbox has two messages" (len (mod/fed-outbox)) 2)
+(mod-fed-test!
+  "outbox message type decision"
+  (get (first (mod/fed-outbox)) :type)
+  "decision")
+(mod-fed-test!
+  "outbox message addressed to peer"
+  (get (first (mod/fed-outbox)) :to)
+  "peerB")
+
+;; ── receiving a peer decision: advisory unless trusted ──
+
+(define mod-fed-untrusted (mod/fed-receive-decision "peerZ" {:action "remove" :rule "reviewer-remove" :report-id "rx"}))
+(mod-fed-test!
+  "untrusted decision not applied"
+  (get mod-fed-untrusted :applied)
+  false)
+(mod-fed-test!
+  "untrusted decision advisory"
+  (get mod-fed-untrusted :advisory)
+  true)
+(mod-fed-test!
+  "untrusted decision absent from applied log"
+  (mod/fed-applied-action "rx")
+  nil)
+(mod-fed-test!
+  "advisory log records suggestion"
+  (len mod/*fed-advisory*)
+  1)
+
+(mod/grant-trust "peerT" :mod)
+(define mod-fed-trusted (mod/fed-receive-decision "peerT" {:action "hide" :rule "spam-hide" :report-id "ry"}))
+(mod-fed-test! "trusted decision applied" (get mod-fed-trusted :applied) true)
+(mod-fed-test!
+  "trusted decision binds locally"
+  (get (mod/fed-applied-action "ry") :action)
+  "hide")
+
+;; ── revocation ──
+
+(mod-fed-test!
+  "applied action not yet revoked"
+  (get (mod/fed-applied-action "ry") :revoked)
+  false)
+(mod/fed-revoke! "ry" "manual")
+(mod-fed-test!
+  "revoke marks applied action revoked"
+  (get (mod/fed-applied-action "ry") :revoked)
+  true)
+(mod-fed-test!
+  "revoke emits a revocation message"
+  (mod/any? (fn (m) (= (get m :type) "revocation")) (mod/fed-outbox))
+  true)
+
+;; revoke-if-invalidated: proof still holds → no revocation
+(define mod-fed-spam-r (mod/mk-report "rs" "a" "b" "this is spam"))
+(define
+  mod-fed-spam-d
+  (mod/decide-report mod-fed-spam-r (list mod-fed-spam-r) mod/default-rules))
+(mod-fed-test! "spam decision is hide" (get mod-fed-spam-d :action) "hide")
+(define
+  mod-fed-rev-same
+  (mod/fed-revoke-if-invalidated
+    mod-fed-spam-r
+    mod-fed-spam-d
+    (list mod-fed-spam-r)
+    mod/default-rules))
+(mod-fed-test!
+  "valid proof → not revoked"
+  (get mod-fed-rev-same :revoked)
+  false)
+
+;; exoneration invalidates the proof → revocation
+(define
+  mod-fed-exon-r
+  (mod/attach-evidence mod-fed-spam-r (mod/mk-evidence "exonerated" "mod")))
+(define
+  mod-fed-rev-inv
+  (mod/fed-revoke-if-invalidated
+    mod-fed-exon-r
+    mod-fed-spam-d
+    (list mod-fed-exon-r)
+    mod/default-rules))
+(mod-fed-test!
+  "invalidated proof → revoked"
+  (get mod-fed-rev-inv :revoked)
+  true)
+(mod-fed-test!
+  "re-decision after exoneration is keep"
+  (get (get mod-fed-rev-inv :decision) :action)
+  "keep")
+
+(define mod-fed-tests-run! (fn () {:failures mod-fed-failures :total mod-fed-count :passed mod-fed-pass :failed mod-fed-fail}))

lib/mod/tests/link.sx

@@ -0,0 +1,86 @@
+;; lib/mod/tests/link.sx — Ext 4: report linking + dedup.
+
+(define mod-lnk-count 0)
+(define mod-lnk-pass 0)
+(define mod-lnk-fail 0)
+(define mod-lnk-failures (list))
+
+(define
+  mod-lnk-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-lnk-count (+ mod-lnk-count 1))
+      (if
+        (= got expected)
+        (set! mod-lnk-pass (+ mod-lnk-pass 1))
+        (begin
+          (set! mod-lnk-fail (+ mod-lnk-fail 1))
+          (append!
+            mod-lnk-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+;; ── link-key + dedup ──
+
+(define mod-lnk-a (mod/mk-report "r1" "alice" "bob" "this is spam"))
+(define mod-lnk-a2 (mod/mk-report "r2" "alice" "bob" "THIS IS SPAM"))
+(define mod-lnk-b (mod/mk-report "r3" "carol" "bob" "abuse"))
+(define mod-lnk-c (mod/mk-report "r4" "alice" "eve" "this is spam"))
+
+(mod-lnk-test!
+  "identical reports share a link key (case-insensitive reason)"
+  (= (mod/link-key mod-lnk-a) (mod/link-key mod-lnk-a2))
+  true)
+(mod-lnk-test!
+  "different reporter → different key"
+  (= (mod/link-key mod-lnk-a) (mod/link-key mod-lnk-b))
+  false)
+(mod-lnk-test!
+  "different subject → different key"
+  (= (mod/link-key mod-lnk-a) (mod/link-key mod-lnk-c))
+  false)
+
+(define mod-lnk-set (list mod-lnk-a mod-lnk-a2 mod-lnk-b mod-lnk-c))
+(mod-lnk-test!
+  "dedup collapses identical reports"
+  (len (mod/dedup-reports mod-lnk-set))
+  3)
+(mod-lnk-test!
+  "duplicate-count counts collapsed"
+  (mod/duplicate-count mod-lnk-set)
+  1)
+(mod-lnk-test!
+  "dedup of all-distinct keeps all"
+  (len (mod/dedup-reports (list mod-lnk-a mod-lnk-b mod-lnk-c)))
+  3)
+
+;; ── Prolog-backed relational linking ──
+
+(mod-lnk-test!
+  "related-ids finds all reports about subject"
+  (len (mod/related-ids "bob" mod-lnk-set))
+  3)
+(mod-lnk-test!
+  "related-ids returns the ids"
+  (mod/related-ids "eve" mod-lnk-set)
+  (list "r4"))
+(mod-lnk-test!
+  "related-ids empty for unknown subject"
+  (mod/related-ids "nobody" mod-lnk-set)
+  (list))
+
+;; reporters: bob reported by alice (x2) + carol → 3 raw, 2 distinct
+(mod-lnk-test!
+  "reporters-of counts all reports"
+  (len (mod/reporters-of "bob" mod-lnk-set))
+  3)
+(mod-lnk-test!
+  "distinct reporters-of dedups reporters"
+  (len (mod/distinct-reporters-of "bob" mod-lnk-set))
+  2)
+(mod-lnk-test!
+  "distinct utility removes dups"
+  (mod/distinct (list "a" "b" "a" "c" "b"))
+  (list "a" "b" "c"))
+
+(define mod-link-tests-run! (fn () {:failures mod-lnk-failures :total mod-lnk-count :passed mod-lnk-pass :failed mod-lnk-fail}))

lib/mod/tests/lint.sx

@@ -0,0 +1,122 @@
+;; lib/mod/tests/lint.sx — Ext 5: policy rule-set static analysis.
+
+(define mod-lint-count 0)
+(define mod-lint-pass 0)
+(define mod-lint-fail 0)
+(define mod-lint-failures (list))
+
+(define
+  mod-lint-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-lint-count (+ mod-lint-count 1))
+      (if
+        (= got expected)
+        (set! mod-lint-pass (+ mod-lint-pass 1))
+        (begin
+          (set! mod-lint-fail (+ mod-lint-fail 1))
+          (append!
+            mod-lint-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+;; ── the default rule set is well-formed ──
+
+(mod-lint-test!
+  "default rules: no unreachable"
+  (mod/unreachable-rules mod/default-rules)
+  (list))
+(mod-lint-test!
+  "default rules: has catch-all"
+  (mod/has-catchall? mod/default-rules)
+  true)
+(mod-lint-test!
+  "default rules: no duplicate names"
+  (mod/duplicate-rule-names mod/default-rules)
+  (list))
+(mod-lint-test!
+  "default rules: well-formed"
+  (mod/rules-ok? mod/default-rules)
+  true)
+
+;; ── unreachable detection ──
+
+(define
+  mod-lint-shadowed
+  (list
+    (mod/mk-rule "spam-hide" :hide (list (list :classification "spam")))
+    (mod/mk-rule "catch-all" :keep (list))
+    (mod/mk-rule
+      "abuse-remove"
+      :remove (list (list :classification "abuse")))
+    (mod/mk-rule
+      "repeated"
+      :escalate (list (list :count-at-least 3)))))
+
+(mod-lint-test!
+  "rules after catch-all are unreachable"
+  (mod/unreachable-rules mod-lint-shadowed)
+  (list "abuse-remove" "repeated"))
+(mod-lint-test!
+  "shadowed rule set is not ok"
+  (mod/rules-ok? mod-lint-shadowed)
+  false)
+
+;; ── missing catch-all ──
+
+(define
+  mod-lint-nocatch
+  (list
+    (mod/mk-rule "spam-hide" :hide (list (list :classification "spam")))
+    (mod/mk-rule
+      "abuse-remove"
+      :remove (list (list :classification "abuse")))))
+
+(mod-lint-test!
+  "no catch-all detected"
+  (mod/has-catchall? mod-lint-nocatch)
+  false)
+(mod-lint-test!
+  "no unreachable when no catch-all"
+  (mod/unreachable-rules mod-lint-nocatch)
+  (list))
+(mod-lint-test!
+  "no-catch-all rule set is not ok"
+  (mod/rules-ok? mod-lint-nocatch)
+  false)
+
+;; ── duplicate names ──
+
+(define
+  mod-lint-dups
+  (list
+    (mod/mk-rule "x" :hide (list (list :classification "spam")))
+    (mod/mk-rule "x" :remove (list (list :classification "abuse")))
+    (mod/mk-rule "default" :keep (list))))
+
+(mod-lint-test!
+  "duplicate names detected"
+  (mod/duplicate-rule-names mod-lint-dups)
+  (list "x"))
+(mod-lint-test!
+  "duplicate-name rule set is not ok"
+  (mod/rules-ok? mod-lint-dups)
+  false)
+
+;; ── helpers ──
+
+(mod-lint-test!
+  "rule-unconditional? true for empty when"
+  (mod/rule-unconditional? (mod/mk-rule "d" :keep (list)))
+  true)
+(mod-lint-test!
+  "rule-unconditional? false with conditions"
+  (mod/rule-unconditional?
+    (mod/mk-rule "s" :hide (list (list :classification "spam"))))
+  false)
+(mod-lint-test!
+  "count-eq counts occurrences"
+  (mod/count-eq "a" (list "a" "b" "a"))
+  2)
+
+(define mod-lint-tests-run! (fn () {:failures mod-lint-failures :total mod-lint-count :passed mod-lint-pass :failed mod-lint-fail}))

lib/mod/tests/offenders.sx

@@ -0,0 +1,115 @@
+;; lib/mod/tests/offenders.sx — Ext 7: repeat-offender escalation.
+
+(define mod-off-count 0)
+(define mod-off-pass 0)
+(define mod-off-fail 0)
+(define mod-off-failures (list))
+
+(define
+  mod-off-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-off-count (+ mod-off-count 1))
+      (if
+        (= got expected)
+        (set! mod-off-pass (+ mod-off-pass 1))
+        (begin
+          (set! mod-off-fail (+ mod-off-fail 1))
+          (append!
+            mod-off-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+;; ── sanction? predicate ──
+
+(mod-off-test! "hide is a sanction" (mod/sanction? "hide") true)
+(mod-off-test! "remove is a sanction" (mod/sanction? "remove") true)
+(mod-off-test! "ban is a sanction" (mod/sanction? "ban") true)
+(mod-off-test! "keep is not a sanction" (mod/sanction? "keep") false)
+(mod-off-test! "escalate is not a sanction" (mod/sanction? "escalate") false)
+
+;; ── repeat-offender escalation over the audit log ──
+
+(mod/reset!)
+(mod/report "u1" "spammer" "this is spam")
+(mod/report "u2" "spammer" "buy now offer")
+(mod/report "u3" "spammer" "click here free money")
+(mod/report "u4" "innocent" "fine post")
+
+(mod-off-test!
+  "no sanctions before any decision"
+  (mod/subject-sanctions "spammer")
+  0)
+
+(define mod-off-d1 (mod/decide-escalating "r1" 2))
+(mod-off-test!
+  "first spam → hide (0 priors)"
+  (get mod-off-d1 :action)
+  "hide")
+(mod-off-test!
+  "one sanction recorded"
+  (mod/subject-sanctions "spammer")
+  1)
+
+(define mod-off-d2 (mod/decide-escalating "r2" 2))
+(mod-off-test!
+  "second spam → hide (1 prior, below k=2)"
+  (get mod-off-d2 :action)
+  "hide")
+(mod-off-test!
+  "two sanctions recorded"
+  (mod/subject-sanctions "spammer")
+  2)
+
+(define mod-off-d3 (mod/decide-escalating "r3" 2))
+(mod-off-test!
+  "third spam → ban (2 priors ≥ k)"
+  (get mod-off-d3 :action)
+  "ban")
+(mod-off-test!
+  "ban decision names repeat-offender rule"
+  (get mod-off-d3 :rule)
+  "repeat-offender-ban")
+(mod-off-test!
+  "ban proof records prior sanction count"
+  (get (get mod-off-d3 :proof) :prior-sanctions)
+  2)
+
+;; ── different subjects accumulate independently ──
+
+(define mod-off-d4 (mod/decide-escalating "r4" 2))
+(mod-off-test!
+  "innocent keep → not escalated"
+  (get mod-off-d4 :action)
+  "keep")
+(mod-off-test!
+  "innocent has no sanctions"
+  (mod/subject-sanctions "innocent")
+  0)
+(mod-off-test!
+  "repeat-offender? true for spammer at k=2"
+  (mod/repeat-offender? "spammer" 2)
+  true)
+(mod-off-test!
+  "repeat-offender? false for innocent at k=1"
+  (mod/repeat-offender? "innocent" 1)
+  false)
+
+;; ── non-sanction decisions are never upgraded to ban ──
+;; r5 is a clean post, but it is the 4th report about "spammer", so the
+;; repeated-report rule escalates it. escalate is not a sanction, so it passes
+;; through decide-escalating unchanged (never becomes :ban).
+
+(mod/report "u5" "spammer" "a perfectly fine post")
+(define mod-off-d5 (mod/decide-escalating "r5" 1))
+(mod-off-test!
+  "non-sanction (escalate) decision is not upgraded to ban"
+  (get mod-off-d5 :action)
+  "escalate")
+
+(mod-off-test!
+  "decide-escalating unknown id → nil"
+  (mod/decide-escalating "r99" 2)
+  nil)
+
+(define mod-offenders-tests-run! (fn () {:failures mod-off-failures :total mod-off-count :passed mod-off-pass :failed mod-off-fail}))

lib/mod/tests/pipeline.sx

@@ -0,0 +1,112 @@
+;; lib/mod/tests/pipeline.sx — Ext 19: end-to-end triage orchestration.
+
+(define mod-pp-count 0)
+(define mod-pp-pass 0)
+(define mod-pp-fail 0)
+(define mod-pp-failures (list))
+
+(define
+  mod-pp-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-pp-count (+ mod-pp-count 1))
+      (if
+        (= got expected)
+        (set! mod-pp-pass (+ mod-pp-pass 1))
+        (begin
+          (set! mod-pp-fail (+ mod-pp-fail 1))
+          (append!
+            mod-pp-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+(mod/policies-reset!)
+(mod/register-policy!
+  "market"
+  (mod/ruleset
+    (mod/defrule "market-spam-remove" :remove (list :classification "spam"))
+    (mod/defrule "default-keep" :keep)))
+
+;; ── spam in the market domain: full bundle ──
+
+(define mod-pp-spam (mod/mk-report "r1" "u" "bob" "this is spam"))
+(define
+  mod-pp
+  (mod/triage-pipeline "market" mod-pp-spam (list mod-pp-spam) "inst.example"))
+
+(mod-pp-test!
+  "pipeline action (market policy → remove)"
+  (mod/pipeline-action mod-pp)
+  "remove")
+(mod-pp-test! "pipeline rule" (get mod-pp :rule) "market-spam-remove")
+(mod-pp-test!
+  "pipeline explanation mentions the action"
+  (mod/str-contains? (get mod-pp :explanation) "remove")
+  true)
+(mod-pp-test!
+  "pipeline activity is Delete (remove)"
+  (get (mod/pipeline-activity mod-pp) :type)
+  "Delete")
+(mod-pp-test!
+  "pipeline activity object is the report"
+  (get (mod/pipeline-activity mod-pp) :object)
+  "r1")
+(mod-pp-test!
+  "pipeline wire round-trips to the same action"
+  (get (mod/wire->decision (mod/pipeline-wire mod-pp)) :action)
+  "remove")
+
+;; ── same report, blog domain (default) → hide, Flag ──
+
+(define
+  mod-pp-blog
+  (mod/triage-pipeline "blog" mod-pp-spam (list mod-pp-spam) "inst.example"))
+(mod-pp-test!
+  "blog default policy → hide"
+  (mod/pipeline-action mod-pp-blog)
+  "hide")
+(mod-pp-test!
+  "blog activity is Flag"
+  (get (mod/pipeline-activity mod-pp-blog) :type)
+  "Flag")
+
+;; ── clean report: keep, no activity, explanation says (none) ──
+
+(define mod-pp-clean (mod/mk-report "r2" "u" "eve" "a fine post"))
+(define
+  mod-pp-k
+  (mod/triage-pipeline
+    "market"
+    mod-pp-clean
+    (list mod-pp-clean)
+    "inst.example"))
+(mod-pp-test! "clean → keep" (mod/pipeline-action mod-pp-k) "keep")
+(mod-pp-test! "keep → no activity" (mod/pipeline-activity mod-pp-k) nil)
+(mod-pp-test!
+  "keep explanation says no evidence"
+  (mod/str-contains? (get mod-pp-k :explanation) "Evidence: (none)")
+  true)
+(mod-pp-test!
+  "keep wire still round-trips"
+  (get (mod/wire->decision (mod/pipeline-wire mod-pp-k)) :rule)
+  "default-keep")
+
+;; ── federated handoff: market decision crosses to a peer, trust-gated ──
+
+(mod/fed-reset!)
+(define mod-pp-peer-dec (mod/wire->decision (mod/pipeline-wire mod-pp)))
+(mod-pp-test!
+  "untrusted peer: market decision is advisory"
+  (get (mod/fed-receive-decision "peerX" mod-pp-peer-dec) :applied)
+  false)
+(mod/grant-trust "peerY" :mod)
+(mod-pp-test!
+  "trusted peer: market decision applies"
+  (get (mod/fed-receive-decision "peerY" mod-pp-peer-dec) :applied)
+  true)
+(mod-pp-test!
+  "applied action is remove"
+  (get (mod/fed-applied-action "r1") :action)
+  "remove")
+
+(define mod-pipeline-tests-run! (fn () {:failures mod-pp-failures :total mod-pp-count :passed mod-pp-pass :failed mod-pp-fail}))

lib/mod/tests/policies.sx

@@ -0,0 +1,112 @@
+;; lib/mod/tests/policies.sx — Ext 17: per-domain policy registry.
+
+(define mod-pol-count 0)
+(define mod-pol-pass 0)
+(define mod-pol-fail 0)
+(define mod-pol-failures (list))
+
+(define
+  mod-pol-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-pol-count (+ mod-pol-count 1))
+      (if
+        (= got expected)
+        (set! mod-pol-pass (+ mod-pol-pass 1))
+        (begin
+          (set! mod-pol-fail (+ mod-pol-fail 1))
+          (append!
+            mod-pol-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+(mod/policies-reset!)
+
+;; market is strict: spam is removed outright, not just hidden
+(define
+  mod-pol-market-rules
+  (list
+    (mod/mk-rule
+      "market-spam-remove"
+      :remove (list (list :classification "spam")))
+    (mod/mk-rule "default-keep" :keep (list))))
+
+(mod-pol-test!
+  "unregistered domain falls back to default"
+  (mod/policy-registered? "market")
+  false)
+(mod/register-policy! "market" mod-pol-market-rules)
+(mod-pol-test!
+  "domain registered after register!"
+  (mod/policy-registered? "market")
+  true)
+
+(define mod-pol-spam (mod/mk-report "r1" "a" "b" "this is spam"))
+
+;; ── same report, different domain → different action ──
+
+(mod-pol-test!
+  "market policy removes spam"
+  (get (mod/decide-in "market" mod-pol-spam (list mod-pol-spam)) :action)
+  "remove")
+(mod-pol-test!
+  "market decision uses market rule"
+  (get (mod/decide-in "market" mod-pol-spam (list mod-pol-spam)) :rule)
+  "market-spam-remove")
+(mod-pol-test!
+  "blog (unregistered) uses default → hide"
+  (get (mod/decide-in "blog" mod-pol-spam (list mod-pol-spam)) :action)
+  "hide")
+(mod-pol-test!
+  "blog decision uses default rule"
+  (get (mod/decide-in "blog" mod-pol-spam (list mod-pol-spam)) :rule)
+  "spam-hide")
+
+;; ── policy-for resolution ──
+
+(mod-pol-test!
+  "policy-for market returns market rules"
+  (mod/policy-for "market")
+  mod-pol-market-rules)
+(mod-pol-test!
+  "policy-for unknown returns default"
+  (mod/policy-for "events")
+  mod/default-rules)
+(mod-pol-test!
+  "registered-domains lists market"
+  (mod/registered-domains)
+  (list "market"))
+
+;; ── a second domain ──
+
+(define
+  mod-pol-events-rules
+  (list (mod/mk-rule "events-keep-all" :keep (list))))
+
+(mod/register-policy! "events" mod-pol-events-rules)
+(mod-pol-test!
+  "events policy keeps everything (even spam)"
+  (get (mod/decide-in "events" mod-pol-spam (list mod-pol-spam)) :action)
+  "keep")
+(mod-pol-test!
+  "two domains registered"
+  (len (mod/registered-domains))
+  2)
+(mod-pol-test!
+  "market still removes after second registration"
+  (get (mod/decide-in "market" mod-pol-spam (list mod-pol-spam)) :action)
+  "remove")
+
+;; ── clean report is keep everywhere ──
+
+(define mod-pol-clean (mod/mk-report "r2" "a" "b" "a fine post"))
+(mod-pol-test!
+  "clean report keep in market"
+  (get (mod/decide-in "market" mod-pol-clean (list mod-pol-clean)) :action)
+  "keep")
+(mod-pol-test!
+  "clean report keep in blog"
+  (get (mod/decide-in "blog" mod-pol-clean (list mod-pol-clean)) :action)
+  "keep")
+
+(define mod-policies-tests-run! (fn () {:failures mod-pol-failures :total mod-pol-count :passed mod-pol-pass :failed mod-pol-fail}))

lib/mod/tests/quorum.sx

@@ -0,0 +1,119 @@
+;; lib/mod/tests/quorum.sx — Ext 8: quorum over distinct reporters.
+
+(define mod-q-count 0)
+(define mod-q-pass 0)
+(define mod-q-fail 0)
+(define mod-q-failures (list))
+
+(define
+  mod-q-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-q-count (+ mod-q-count 1))
+      (if
+        (= got expected)
+        (set! mod-q-pass (+ mod-q-pass 1))
+        (begin
+          (set! mod-q-fail (+ mod-q-fail 1))
+          (append!
+            mod-q-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+(define
+  mod-q-rules
+  (list
+    (mod/mk-rule
+      "quorum-hide"
+      :hide (list (list :reporters-at-least 2)))
+    (mod/mk-rule "default-keep" :keep (list))))
+
+;; ── two distinct reporters meet quorum ──
+
+(define
+  mod-q-two
+  (list
+    (mod/mk-report "r1" "alice" "bob" "off-topic")
+    (mod/mk-report "r2" "carol" "bob" "off-topic")))
+
+(mod-q-test!
+  "two distinct reporters → hide"
+  (get (mod/decide-quorum (first mod-q-two) mod-q-two mod-q-rules) :action)
+  "hide")
+(mod-q-test!
+  "quorum decision names the rule"
+  (get (mod/decide-quorum (first mod-q-two) mod-q-two mod-q-rules) :rule)
+  "quorum-hide")
+(mod-q-test!
+  "quorum decision tagged strategy"
+  (get (mod/decide-quorum (first mod-q-two) mod-q-two mod-q-rules) :strategy)
+  "quorum")
+
+;; ── single reporter does not meet quorum ──
+
+(define mod-q-one (list (mod/mk-report "r1" "alice" "bob" "off-topic")))
+(mod-q-test!
+  "one reporter → keep (below quorum)"
+  (get (mod/decide-quorum (first mod-q-one) mod-q-one mod-q-rules) :action)
+  "keep")
+
+;; ── anti-brigade: one user filing many reports does NOT meet quorum ──
+
+(define
+  mod-q-brigade
+  (list
+    (mod/mk-report "r1" "alice" "bob" "off-topic")
+    (mod/mk-report "r2" "alice" "bob" "off-topic")
+    (mod/mk-report "r3" "alice" "bob" "off-topic")))
+
+(mod-q-test!
+  "three reports, one reporter → keep (quorum counts distinct)"
+  (get
+    (mod/decide-quorum (first mod-q-brigade) mod-q-brigade mod-q-rules)
+    :action)
+  "keep")
+
+;; contrast: the count rule WOULD fire on the same brigade (3 reports ≥ 3) —
+;; quorum is strictly stronger against single-actor brigading
+(mod-q-test!
+  "count rule fires on the brigade (distinct from quorum)"
+  (get
+    (mod/decide-report (first mod-q-brigade) mod-q-brigade mod/default-rules)
+    :action)
+  "escalate")
+
+;; ── three distinct reporters ──
+
+(define
+  mod-q-three
+  (list
+    (mod/mk-report "r1" "alice" "bob" "off-topic")
+    (mod/mk-report "r2" "carol" "bob" "off-topic")
+    (mod/mk-report "r3" "dave" "bob" "off-topic")))
+
+(mod-q-test!
+  "three distinct reporters → hide"
+  (get
+    (mod/decide-quorum (first mod-q-three) mod-q-three mod-q-rules)
+    :action)
+  "hide")
+(mod-q-test!
+  "quorum proof goal solved"
+  (get
+    (first
+      (get
+        (get
+          (mod/decide-quorum (first mod-q-three) mod-q-three mod-q-rules)
+          :proof)
+        :goals))
+    :solved)
+  true)
+
+;; ── cond->goal compiles :reporters-at-least ──
+
+(mod-q-test!
+  "cond->goal :reporters-at-least"
+  (mod/cond->goal (list :reporters-at-least 2) "Id")
+  "report(Id, _, Sr), setof(Br, report(_, Br, Sr), Bsr), length(Bsr, Nr), Nr >= 2")
+
+(define mod-quorum-tests-run! (fn () {:failures mod-q-failures :total mod-q-count :passed mod-q-pass :failed mod-q-fail}))

lib/mod/tests/severity.sx

@@ -0,0 +1,120 @@
+;; lib/mod/tests/severity.sx — Ext 6: strictest-wins decision strategy.
+
+(define mod-sev-count 0)
+(define mod-sev-pass 0)
+(define mod-sev-fail 0)
+(define mod-sev-failures (list))
+
+(define
+  mod-sev-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-sev-count (+ mod-sev-count 1))
+      (if
+        (= got expected)
+        (set! mod-sev-pass (+ mod-sev-pass 1))
+        (begin
+          (set! mod-sev-fail (+ mod-sev-fail 1))
+          (append!
+            mod-sev-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+;; ── severity ranking ──
+
+(mod-sev-test! "ban most severe" (mod/action-severity "ban") 4)
+(mod-sev-test!
+  "remove > hide"
+  (< (mod/action-severity "hide") (mod/action-severity "remove"))
+  true)
+(mod-sev-test! "keep least severe" (mod/action-severity "keep") 0)
+(mod-sev-test!
+  "escalate above keep"
+  (< (mod/action-severity "keep") (mod/action-severity "escalate"))
+  true)
+
+;; ── strictest agrees with default-rules on simple cases ──
+
+(define mod-sev-spam (mod/mk-report "r1" "a" "b" "this is spam"))
+(mod-sev-test!
+  "strictest spam → hide"
+  (get
+    (mod/decide-strictest mod-sev-spam (list mod-sev-spam) mod/default-rules)
+    :action)
+  "hide")
+(define mod-sev-clean (mod/mk-report "r2" "a" "b" "a fine post"))
+(mod-sev-test!
+  "strictest clean → keep"
+  (get
+    (mod/decide-strictest
+      mod-sev-clean
+      (list mod-sev-clean)
+      mod/default-rules)
+    :action)
+  "keep")
+(mod-sev-test!
+  "decision tagged strategy strictest"
+  (get
+    (mod/decide-strictest mod-sev-spam (list mod-sev-spam) mod/default-rules)
+    :strategy)
+  "strictest")
+
+;; ── strictest diverges from first-match when order ≠ severity ──
+
+(define
+  mod-sev-rules
+  (list
+    (mod/mk-rule
+      "early-escalate"
+      :escalate (list (list :count-at-least 1)))
+    (mod/mk-rule "spam-remove" :remove (list (list :classification "spam")))
+    (mod/mk-rule "default-keep" :keep (list))))
+
+(define mod-sev-r (mod/mk-report "r3" "a" "b" "this is spam"))
+
+(mod-sev-test!
+  "first-match picks earliest rule (escalate)"
+  (get (mod/decide-report mod-sev-r (list mod-sev-r) mod-sev-rules) :action)
+  "escalate")
+(mod-sev-test!
+  "strictest picks harshest action (remove)"
+  (get
+    (mod/decide-strictest mod-sev-r (list mod-sev-r) mod-sev-rules)
+    :action)
+  "remove")
+(mod-sev-test!
+  "strictest names the harshest rule"
+  (get (mod/decide-strictest mod-sev-r (list mod-sev-r) mod-sev-rules) :rule)
+  "spam-remove")
+(mod-sev-test!
+  "strictest carries proof goals"
+  (len
+    (get
+      (get
+        (mod/decide-strictest mod-sev-r (list mod-sev-r) mod-sev-rules)
+        :proof)
+      :goals))
+  1)
+
+;; ── strictest among three matches (spam + repeated) ──
+
+(define mod-sev-rep (mod/mk-report "r4" "a" "b" "buy now spam"))
+(define mod-sev-reps (list mod-sev-rep mod-sev-rep mod-sev-rep))
+(mod-sev-test!
+  "strictest among hide+escalate+keep → hide (default rules)"
+  (get
+    (mod/decide-strictest mod-sev-rep mod-sev-reps mod/default-rules)
+    :action)
+  "hide")
+
+;; ── strictest-sol helper ──
+
+(mod-sev-test!
+  "strictest-sol picks max severity"
+  (dict-get
+    (mod/strictest-sol (list {:Action "keep" :Rule "k"} {:Action "remove" :Rule "r"} {:Action "hide" :Rule "h"}))
+    "Action")
+  "remove")
+(mod-sev-test! "strictest-sol nil for empty" (mod/strictest-sol (list)) nil)
+
+(define mod-severity-tests-run! (fn () {:failures mod-sev-failures :total mod-sev-count :passed mod-sev-pass :failed mod-sev-fail}))

lib/mod/tests/sla.sx

@@ -0,0 +1,108 @@
+;; lib/mod/tests/sla.sx — Ext 13: SLA sweep over pending lifecycle cases.
+
+(define mod-sla-count 0)
+(define mod-sla-pass 0)
+(define mod-sla-fail 0)
+(define mod-sla-failures (list))
+
+(define
+  mod-sla-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-sla-count (+ mod-sla-count 1))
+      (if
+        (= got expected)
+        (set! mod-sla-pass (+ mod-sla-pass 1))
+        (begin
+          (set! mod-sla-fail (+ mod-sla-fail 1))
+          (append!
+            mod-sla-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+;; ── pending-state? ──
+
+(mod-sla-test! "open is pending" (mod/pending-state? "open") true)
+(mod-sla-test! "triaged is pending" (mod/pending-state? "triaged") true)
+(mod-sla-test! "appealed is pending" (mod/pending-state? "appealed") true)
+(mod-sla-test! "decided is not pending" (mod/pending-state? "decided") false)
+(mod-sla-test! "final is not pending" (mod/pending-state? "final") false)
+
+;; build cases in known states
+(define mod-sla-spam (mod/mk-report "r1" "u" "bob" "this is spam"))
+(define mod-sla-spam-reports (list mod-sla-spam))
+(define
+  mod-sla-triaged
+  (mod/case-triage
+    (mod/mk-case mod-sla-spam)
+    mod-sla-spam-reports
+    mod/default-rules))
+(define mod-sla-decided (mod/case-resolve mod-sla-triaged))
+(define mod-sla-open (mod/mk-case (mod/mk-report "r2" "u" "eve" "hello")))
+
+;; ── overdue? ──
+
+(define mod-sla-tc-old (mod/mk-timed-case mod-sla-triaged 0))
+(define mod-sla-tc-fresh (mod/mk-timed-case mod-sla-triaged 90))
+(define mod-sla-tc-done (mod/mk-timed-case mod-sla-decided 0))
+
+(mod-sla-test!
+  "old triaged case is overdue"
+  (mod/overdue? mod-sla-tc-old 100 50)
+  true)
+(mod-sla-test!
+  "fresh triaged case not overdue"
+  (mod/overdue? mod-sla-tc-fresh 100 50)
+  false)
+(mod-sla-test!
+  "decided case never overdue"
+  (mod/overdue? mod-sla-tc-done 100 50)
+  false)
+(mod-sla-test!
+  "age computes elapsed ticks"
+  (mod/age mod-sla-tc-old 100)
+  100)
+(mod-sla-test!
+  "boundary: exactly at deadline not overdue"
+  (mod/overdue?
+    (mod/mk-timed-case mod-sla-triaged 50)
+    100
+    50)
+  false)
+(mod-sla-test!
+  "boundary: one past deadline overdue"
+  (mod/overdue?
+    (mod/mk-timed-case mod-sla-triaged 49)
+    100
+    50)
+  true)
+
+;; ── sweep over a mixed queue ──
+
+(define
+  mod-sla-queue
+  (list
+    (mod/mk-timed-case mod-sla-triaged 0)
+    (mod/mk-timed-case mod-sla-decided 0)
+    (mod/mk-timed-case mod-sla-open 90)))      ;; r2, pending, age 10 → not
+
+(mod-sla-test!
+  "sweep finds only the overdue pending case"
+  (mod/sla-sweep mod-sla-queue 100 50)
+  (list "r1"))
+(mod-sla-test!
+  "overdue-count agrees"
+  (mod/overdue-count mod-sla-queue 100 50)
+  1)
+
+;; tighten deadline so the young open case also breaches
+(mod-sla-test!
+  "tighter deadline catches the open case too"
+  (mod/overdue-count mod-sla-queue 100 5)
+  2)
+(mod-sla-test!
+  "empty queue → no breaches"
+  (mod/sla-sweep (list) 100 50)
+  (list))
+
+(define mod-sla-tests-run! (fn () {:failures mod-sla-failures :total mod-sla-count :passed mod-sla-pass :failed mod-sla-fail}))

lib/mod/tests/temporal.sx

@@ -0,0 +1,156 @@
+;; lib/mod/tests/temporal.sx — Ext 12: burst detection over a time window.
+
+(define mod-tm-count 0)
+(define mod-tm-pass 0)
+(define mod-tm-fail 0)
+(define mod-tm-failures (list))
+
+(define
+  mod-tm-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-tm-count (+ mod-tm-count 1))
+      (if
+        (= got expected)
+        (set! mod-tm-pass (+ mod-tm-pass 1))
+        (begin
+          (set! mod-tm-fail (+ mod-tm-fail 1))
+          (append!
+            mod-tm-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+(define
+  mod-tm-at
+  (fn (id about t) (mod/with-at (mod/mk-report id "u" about "off-topic") t)))
+
+(define
+  mod-tm-rules
+  (list
+    (mod/mk-rule "burst-hide" :hide (list (list :burst-at-least 3)))
+    (mod/mk-rule "default-keep" :keep (list))))
+
+;; ── window-count helper ──
+
+(define
+  mod-tm-burst
+  (list
+    (mod-tm-at "r1" "bob" 10)
+    (mod-tm-at "r2" "bob" 11)
+    (mod-tm-at "r3" "bob" 12)))
+(define
+  mod-tm-slow
+  (list
+    (mod-tm-at "r1" "bob" 1)
+    (mod-tm-at "r2" "bob" 2)
+    (mod-tm-at "r3" "bob" 12)))
+
+(mod-tm-test!
+  "window-count: all 3 within window"
+  (mod/window-count "bob" mod-tm-burst 12 5)
+  3)
+(mod-tm-test!
+  "window-count: only 1 within window"
+  (mod/window-count "bob" mod-tm-slow 12 5)
+  1)
+(mod-tm-test!
+  "window-count: subject filter"
+  (mod/window-count "eve" mod-tm-burst 12 5)
+  0)
+
+;; ── burst fires; slow accumulation does not ──
+
+(mod-tm-test!
+  "burst (3 in window) → hide"
+  (get
+    (mod/decide-temporal
+      (first mod-tm-burst)
+      mod-tm-burst
+      mod-tm-rules
+      12
+      5)
+    :action)
+  "hide")
+(mod-tm-test!
+  "slow accumulation (1 in window) → keep"
+  (get
+    (mod/decide-temporal
+      (first mod-tm-slow)
+      mod-tm-slow
+      mod-tm-rules
+      12
+      5)
+    :action)
+  "keep")
+
+;; ── contrast: the plain count rule fires on BOTH (3 total reports) ──
+(mod-tm-test!
+  "count rule fires on slow case (distinct from burst)"
+  (get
+    (mod/decide-report (first mod-tm-slow) mod-tm-slow mod/default-rules)
+    :action)
+  "escalate")
+
+;; ── decision shape ──
+
+(define
+  mod-tm-d
+  (mod/decide-temporal
+    (first mod-tm-burst)
+    mod-tm-burst
+    mod-tm-rules
+    12
+    5))
+(mod-tm-test! "burst decision rule" (get mod-tm-d :rule) "burst-hide")
+(mod-tm-test!
+  "burst decision tagged strategy"
+  (get mod-tm-d :strategy)
+  "temporal")
+(mod-tm-test!
+  "burst recorded in proof"
+  (get (get mod-tm-d :proof) :burst)
+  3)
+(mod-tm-test!
+  "burst proof goal solved"
+  (get (first (get (get mod-tm-d :proof) :goals)) :solved)
+  true)
+
+;; ── window boundary is inclusive ──
+
+(define
+  mod-tm-edge
+  (list
+    (mod-tm-at "r1" "bob" 7)
+    (mod-tm-at "r2" "bob" 8)
+    (mod-tm-at "r3" "bob" 9)))
+(mod-tm-test!
+  "window boundary inclusive (now-window = at)"
+  (mod/window-count "bob" mod-tm-edge 12 5)
+  3)
+
+;; ── schema :at round-trips and survives evidence attach ──
+
+(mod-tm-test!
+  "report-at reads timestamp"
+  (mod/report-at (mod-tm-at "r1" "bob" 42))
+  42)
+(mod-tm-test!
+  "default report-at is 0"
+  (mod/report-at (mod/mk-report "r1" "a" "b" "x"))
+  0)
+(mod-tm-test!
+  "attach-evidence preserves :at"
+  (mod/report-at
+    (mod/attach-evidence
+      (mod-tm-at "r1" "bob" 42)
+      (mod/mk-evidence "k" "v")))
+  42)
+
+;; ── cond->goal :burst-at-least ──
+
+(mod-tm-test!
+  "cond->goal :burst-at-least"
+  (mod/cond->goal (list :burst-at-least 3) "Id")
+  "report(Id, _, Sb), burst_count(Sb, Nb), Nb >= 3")
+
+(define mod-temporal-tests-run! (fn () {:failures mod-tm-failures :total mod-tm-count :passed mod-tm-pass :failed mod-tm-fail}))

lib/mod/tests/trace.sx

@@ -0,0 +1,116 @@
+;; lib/mod/tests/trace.sx — Ext 9: policy dry-run diagnostics.
+
+(define mod-tr-count 0)
+(define mod-tr-pass 0)
+(define mod-tr-fail 0)
+(define mod-tr-failures (list))
+
+(define
+  mod-tr-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-tr-count (+ mod-tr-count 1))
+      (if
+        (= got expected)
+        (set! mod-tr-pass (+ mod-tr-pass 1))
+        (begin
+          (set! mod-tr-fail (+ mod-tr-fail 1))
+          (append!
+            mod-tr-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+(define
+  mod-tr-find
+  (fn
+    (trace nm)
+    (reduce (fn (acc t) (if (= (get t :rule) nm) t acc)) nil trace)))
+
+;; ── trace a spam report against the default rules ──
+
+(define mod-tr-spam (mod/mk-report "r1" "alice" "bob" "this is spam"))
+(define
+  mod-tr-t
+  (mod/trace-rules mod-tr-spam (list mod-tr-spam) mod/default-rules))
+
+(mod-tr-test! "trace covers every rule" (len mod-tr-t) 6)
+(mod-tr-test!
+  "spam-hide fires"
+  (get (mod-tr-find mod-tr-t "spam-hide") :proved)
+  true)
+(mod-tr-test!
+  "default-keep always fires"
+  (get (mod-tr-find mod-tr-t "default-keep") :proved)
+  true)
+(mod-tr-test!
+  "reviewer-remove does not fire (no evidence)"
+  (get (mod-tr-find mod-tr-t "reviewer-remove") :proved)
+  false)
+(mod-tr-test!
+  "exonerated-keep does not fire"
+  (get (mod-tr-find mod-tr-t "exonerated-keep") :proved)
+  false)
+(mod-tr-test!
+  "abuse-remove does not fire"
+  (get (mod-tr-find mod-tr-t "abuse-remove") :proved)
+  false)
+
+;; ── winner matches the engine ──
+
+(mod-tr-test!
+  "first-proved is spam-hide"
+  (get (mod/first-proved mod-tr-t) :rule)
+  "spam-hide")
+(mod-tr-test!
+  "winner action matches decide-report"
+  (get (mod/first-proved mod-tr-t) :action)
+  (get
+    (mod/decide-report mod-tr-spam (list mod-tr-spam) mod/default-rules)
+    :action))
+
+;; ── an unproved rule shows which goal failed ──
+
+(define
+  mod-tr-rev-goals
+  (get (mod-tr-find mod-tr-t "reviewer-remove") :goals))
+(mod-tr-test!
+  "reviewer-remove goal is unsolved"
+  (get (first mod-tr-rev-goals) :solved)
+  false)
+(define mod-tr-spam-goals (get (mod-tr-find mod-tr-t "spam-hide") :goals))
+(mod-tr-test!
+  "spam-hide goal is solved"
+  (get (first mod-tr-spam-goals) :solved)
+  true)
+
+;; ── proved-rules list + rendering ──
+
+(mod-tr-test!
+  "proved-rules lists fired rules in order"
+  (mod/proved-rules mod-tr-t)
+  (list "spam-hide" "default-keep"))
+(mod-tr-test!
+  "trace-report marks a firing rule"
+  (mod/str-contains? (mod/trace-report mod-tr-t) "[fires] spam-hide")
+  true)
+(mod-tr-test!
+  "trace-report marks a non-firing rule"
+  (mod/str-contains? (mod/trace-report mod-tr-t) "[  -  ] reviewer-remove")
+  true)
+
+;; ── clean report: only default-keep fires ──
+
+(define mod-tr-clean (mod/mk-report "r2" "a" "b" "a fine post"))
+(define
+  mod-tr-tc
+  (mod/trace-rules mod-tr-clean (list mod-tr-clean) mod/default-rules))
+(mod-tr-test!
+  "clean report: only default-keep proves"
+  (mod/proved-rules mod-tr-tc)
+  (list "default-keep"))
+(mod-tr-test!
+  "clean report winner is default-keep"
+  (get (mod/first-proved mod-tr-tc) :rule)
+  "default-keep")
+
+(define mod-trace-tests-run! (fn () {:failures mod-tr-failures :total mod-tr-count :passed mod-tr-pass :failed mod-tr-fail}))

lib/mod/tests/whatif.sx

@@ -0,0 +1,117 @@
+;; lib/mod/tests/whatif.sx — Ext 10: policy what-if / impact analysis.
+
+(define mod-wi-count 0)
+(define mod-wi-pass 0)
+(define mod-wi-fail 0)
+(define mod-wi-failures (list))
+
+(define
+  mod-wi-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-wi-count (+ mod-wi-count 1))
+      (if
+        (= got expected)
+        (set! mod-wi-pass (+ mod-wi-pass 1))
+        (begin
+          (set! mod-wi-fail (+ mod-wi-fail 1))
+          (append!
+            mod-wi-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+;; rules-b is the default policy with spam-hide removed: spam now falls through
+;; to default-keep. A spam report flips hide → keep; everything else is unchanged.
+(define mod-wi-rules-a mod/default-rules)
+(define
+  mod-wi-rules-b
+  (list
+    (mod/mk-rule
+      "reviewer-remove"
+      :remove (list (list :evidence "confirmed-abuse")))
+    (mod/mk-rule
+      "abuse-remove"
+      :remove (list (list :classification "abuse")))
+    (mod/mk-rule
+      "repeated-escalate"
+      :escalate (list (list :count-at-least 3)))
+    (mod/mk-rule "default-keep" :keep (list))))
+
+(define mod-wi-spam (mod/mk-report "r1" "a" "bob" "this is spam"))
+(define mod-wi-abuse (mod/mk-report "r2" "a" "carol" "harassment here"))
+(define mod-wi-clean (mod/mk-report "r3" "a" "dave" "a fine post"))
+
+;; ── single-report diff ──
+
+(define
+  mod-wi-d
+  (mod/decision-diff
+    mod-wi-spam
+    (list mod-wi-spam)
+    mod-wi-rules-a
+    mod-wi-rules-b))
+(mod-wi-test! "spam before = hide" (get mod-wi-d :before) "hide")
+(mod-wi-test! "spam after = keep" (get mod-wi-d :after) "keep")
+(mod-wi-test! "spam decision flips" (get mod-wi-d :changed) true)
+(mod-wi-test! "diff carries report id" (get mod-wi-d :report-id) "r1")
+
+(define
+  mod-wi-da
+  (mod/decision-diff
+    mod-wi-abuse
+    (list mod-wi-abuse)
+    mod-wi-rules-a
+    mod-wi-rules-b))
+(mod-wi-test! "abuse unchanged (remove both)" (get mod-wi-da :changed) false)
+(mod-wi-test! "abuse stays remove" (get mod-wi-da :after) "remove")
+
+(define
+  mod-wi-dc
+  (mod/decision-diff
+    mod-wi-clean
+    (list mod-wi-clean)
+    mod-wi-rules-a
+    mod-wi-rules-b))
+(mod-wi-test! "clean unchanged (keep both)" (get mod-wi-dc :changed) false)
+
+;; ── batch impact ──
+
+(define mod-wi-batch (list mod-wi-spam mod-wi-abuse mod-wi-clean))
+(define
+  mod-wi-impact
+  (mod/policy-impact mod-wi-batch mod-wi-rules-a mod-wi-rules-b))
+
+(mod-wi-test!
+  "impact lists only changed reports"
+  (len mod-wi-impact)
+  1)
+(mod-wi-test!
+  "impacted report is the spam one"
+  (get (first mod-wi-impact) :report-id)
+  "r1")
+(mod-wi-test!
+  "impact-count agrees"
+  (mod/impact-count mod-wi-batch mod-wi-rules-a mod-wi-rules-b)
+  1)
+
+;; ── identical rule sets → no impact ──
+
+(mod-wi-test!
+  "same rules → zero impact"
+  (mod/impact-count mod-wi-batch mod-wi-rules-a mod-wi-rules-a)
+  0)
+(mod-wi-test!
+  "same rules → empty report"
+  (mod/impact-report mod-wi-batch mod-wi-rules-a mod-wi-rules-a)
+  "No decisions change.")
+
+;; ── rendering ──
+
+(mod-wi-test!
+  "impact-report renders the flip"
+  (mod/str-contains?
+    (mod/impact-report mod-wi-batch mod-wi-rules-a mod-wi-rules-b)
+    "r1: hide → keep")
+  true)
+
+(define mod-whatif-tests-run! (fn () {:failures mod-wi-failures :total mod-wi-count :passed mod-wi-pass :failed mod-wi-fail}))

lib/mod/tests/wire.sx

@@ -0,0 +1,96 @@
+;; lib/mod/tests/wire.sx — Ext 14: decision wire format + federated transport.
+
+(define mod-w-count 0)
+(define mod-w-pass 0)
+(define mod-w-fail 0)
+(define mod-w-failures (list))
+
+(define
+  mod-w-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-w-count (+ mod-w-count 1))
+      (if
+        (= got expected)
+        (set! mod-w-pass (+ mod-w-pass 1))
+        (begin
+          (set! mod-w-fail (+ mod-w-fail 1))
+          (append!
+            mod-w-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+;; ── split-char ──
+
+(mod-w-test! "split on pipe" (mod/split-char "a|b|c" "|") (list "a" "b" "c"))
+(mod-w-test! "split single field" (mod/split-char "abc" "|") (list "abc"))
+(mod-w-test!
+  "split four fields"
+  (len (mod/split-char "MOD1|r1|hide|spam-hide" "|"))
+  4)
+
+;; ── serialize ──
+
+(define
+  mod-w-dec
+  (mod/decide-report
+    (mod/mk-report "r1" "a" "bob" "this is spam")
+    (list (mod/mk-report "r1" "a" "bob" "this is spam"))
+    mod/default-rules))
+(define mod-w-line (mod/decision->wire mod-w-dec))
+
+(mod-w-test!
+  "wire is versioned + delimited"
+  mod-w-line
+  "MOD1|r1|hide|spam-hide")
+(mod-w-test!
+  "wire-valid? accepts well-formed"
+  (mod/wire-valid? mod-w-line)
+  true)
+(mod-w-test!
+  "wire-valid? rejects junk"
+  (mod/wire-valid? "not a wire line")
+  false)
+(mod-w-test!
+  "wire-valid? rejects wrong version"
+  (mod/wire-valid? "MOD9|r1|hide|x")
+  false)
+
+;; ── round-trip ──
+
+(define mod-w-back (mod/wire->decision mod-w-line))
+(mod-w-test! "round-trip report-id" (get mod-w-back :report-id) "r1")
+(mod-w-test! "round-trip action" (get mod-w-back :action) "hide")
+(mod-w-test! "round-trip rule" (get mod-w-back :rule) "spam-hide")
+(mod-w-test! "round-trip tags :wire" (get mod-w-back :wire) true)
+(mod-w-test! "malformed → nil" (mod/wire->decision "garbage") nil)
+
+;; ── full federated transport: serialize → wire → deserialize → trust-gate ──
+
+(mod/fed-reset!)
+(define mod-w-peer-dec (mod/wire->decision mod-w-line))
+
+;; untrusted peer: decision is advisory, not applied
+(define mod-w-recv1 (mod/fed-receive-decision "peerX" mod-w-peer-dec))
+(mod-w-test!
+  "wired decision from untrusted peer → advisory"
+  (get mod-w-recv1 :applied)
+  false)
+(mod-w-test!
+  "untrusted wired decision not applied locally"
+  (mod/fed-applied-action "r1")
+  nil)
+
+;; trusted peer: decision binds locally
+(mod/grant-trust "peerY" :mod)
+(define mod-w-recv2 (mod/fed-receive-decision "peerY" mod-w-peer-dec))
+(mod-w-test!
+  "wired decision from trusted peer → applied"
+  (get mod-w-recv2 :applied)
+  true)
+(mod-w-test!
+  "trusted wired decision binds locally"
+  (get (mod/fed-applied-action "r1") :action)
+  "hide")
+
+(define mod-wire-tests-run! (fn () {:failures mod-w-failures :total mod-w-count :passed mod-w-pass :failed mod-w-fail}))

lib/mod/trace.sx

@@ -0,0 +1,56 @@
+;; lib/mod/trace.sx — policy dry-run diagnostics.
+;;
+;; decide-report returns the winning rule; a policy author debugging "why didn't
+;; my rule fire?" needs the whole picture. mod/trace-rules evaluates a report
+;; against every rule and reports each rule's proved/unproved status plus its
+;; goal-by-goal derivation — so an unproved rule shows exactly which goal failed.
+;; The winner is the first proved rule (same precedence as the engine).
+
+(define
+  mod/trace-rules
+  (fn
+    (r reports rules)
+    (let
+      ((count (mod/report-count (mod/report-about r) reports))
+        (id (mod/report-id r)))
+      (let
+        ((db (pl-load (mod/build-program r count rules))))
+        (let
+          ((proved-names (map (fn (s) (dict-get s "Rule")) (pl-query-all db (str "policy_action(" id ", _, Rule)")))))
+          (map
+            (fn (rule) (let ((nm (mod/rule-name rule))) {:proved (mod/member? nm proved-names) :goals (mod/proof-goals db id (mod/rule-when rule)) :action (mod/rule-action rule) :rule nm}))
+            rules))))))
+
+(define
+  mod/first-proved
+  (fn
+    (trace)
+    (reduce
+      (fn (acc t) (if (nil? acc) (if (get t :proved) t acc) acc))
+      nil
+      trace)))
+
+(define
+  mod/proved-rules
+  (fn
+    (trace)
+    (reduce
+      (fn
+        (acc t)
+        (if (get t :proved) (append acc (list (get t :rule))) acc))
+      (list)
+      trace)))
+
+(define
+  mod/trace-row
+  (fn
+    (t)
+    (str
+      (if (get t :proved) "[fires] " "[  -  ] ")
+      (get t :rule)
+      " → "
+      (get t :action))))
+
+(define
+  mod/trace-report
+  (fn (trace) (mod/join-with "\n" (map mod/trace-row trace))))

lib/mod/whatif.sx

@@ -0,0 +1,56 @@
+;; lib/mod/whatif.sx — policy what-if / impact analysis.
+;;
+;; Before shipping a policy change, a moderation team needs to know which past or
+;; pending reports would decide differently. mod/decision-diff compares one
+;; report's action under two rule sets; mod/policy-impact runs a whole batch and
+;; returns only the reports whose decision flips. Pure SX over decide-report.
+
+(define
+  mod/decision-diff
+  (fn
+    (r reports rules-a rules-b)
+    (let
+      ((a (get (mod/decide-report r reports rules-a) :action))
+        (b (get (mod/decide-report r reports rules-b) :action)))
+      {:after b :changed (if (= a b) false true) :report-id (mod/report-id r) :before a})))
+
+(define
+  mod/policy-impact
+  (fn
+    (reports rules-a rules-b)
+    (reduce
+      (fn
+        (acc r)
+        (let
+          ((d (mod/decision-diff r reports rules-a rules-b)))
+          (if (get d :changed) (append acc (list d)) acc)))
+      (list)
+      reports)))
+
+(define
+  mod/impact-count
+  (fn
+    (reports rules-a rules-b)
+    (len (mod/policy-impact reports rules-a rules-b))))
+
+(define
+  mod/impact-report
+  (fn
+    (reports rules-a rules-b)
+    (let
+      ((changed (mod/policy-impact reports rules-a rules-b)))
+      (if
+        (empty? changed)
+        "No decisions change."
+        (mod/join-with
+          "\n"
+          (map
+            (fn
+              (d)
+              (str
+                (get d :report-id)
+                ": "
+                (get d :before)
+                " → "
+                (get d :after)))
+            changed))))))

lib/mod/wire.sx

@@ -0,0 +1,55 @@
+;; lib/mod/wire.sx — portable decision wire format for federation transport.
+;;
+;; fed.sx shares decisions as in-memory dicts and leaves mod/fed-send! as the
+;; transport seam. This is the bytes that cross it: a versioned, pipe-delimited
+;; line encoding the verdict a peer needs (report id, action, rule) — enough to
+;; trust-gate and apply/advise, without shipping the whole proof tree. The
+;; loaded env has no string split, so split is built over slice/len.
+
+(define
+  mod/split-loop
+  (fn
+    (s ch n start pos acc)
+    (if
+      (= pos n)
+      (append acc (list (slice s start n)))
+      (if
+        (= (slice s pos (+ pos 1)) ch)
+        (mod/split-loop
+          s
+          ch
+          n
+          (+ pos 1)
+          (+ pos 1)
+          (append acc (list (slice s start pos))))
+        (mod/split-loop s ch n start (+ pos 1) acc)))))
+
+(define
+  mod/split-char
+  (fn (s ch) (mod/split-loop s ch (len s) 0 0 (list))))
+
+(define
+  mod/decision->wire
+  (fn
+    (d)
+    (str "MOD1|" (get d :report-id) "|" (get d :action) "|" (get d :rule))))
+
+(define
+  mod/wire-valid?
+  (fn
+    (w)
+    (let
+      ((parts (mod/split-char w "|")))
+      (if
+        (= (len parts) 4)
+        (= (nth parts 0) "MOD1")
+        false))))
+
+(define
+  mod/wire->decision
+  (fn
+    (w)
+    (if
+      (mod/wire-valid? w)
+      (let ((parts (mod/split-char w "|"))) {:action (nth parts 2) :wire true :rule (nth parts 3) :report-id (nth parts 1)})
+      nil)))

next/.gitignore

@@ -1 +0,0 @@
-data/

next/README.md

@@ -1,170 +0,0 @@
-# next — fed-sx Milestone 1 kernel
-
-Single-instance, single-actor fed-sx server built as Erlang-on-SX modules.
-See `plans/fed-sx-design.md` for the architecture and
-`plans/fed-sx-milestone-1.md` for the build plan + per-step progress log.
-
-## Status
-
-Both Step 9 smoke proof points are functional **in-process**:
-
-- **9a-pure (verb extensibility)** — `Create{DefineActivity{Pin}}` registers Pin
-  at runtime; subsequent `Pin{path, cid}` activities fold into a pin-state
-  projection. Zero kernel code between definition and use.
-  See `next/tests/smoke_pin_pure.sh`.
-- **9b-pure (reactive application)** — A trigger projection matches Notes
-  tagged `smoketest` and derives a `TestEcho` carrying the source CID.
-  See `next/tests/smoke_app_pure.sh`.
-
-The remaining `9a-tcp` / `9b-tcp` deliverables layer TCP transport on top — see
-*Substrate gaps* below.
-
-## Layout
-
-```
-next/
-├── kernel/      Erlang-on-SX kernel modules (.erl)
-├── genesis/     SX source files for the bootstrap bundle
-├── tests/       Bash test scripts driving sx_server.exe via the epoch protocol
-└── data/        Runtime state — gitignored
-```
-
-## Module map
-
-| Module                | Role                                                                   |
-|-----------------------|------------------------------------------------------------------------|
-| `nx_cid.erl`          | Canonical CID wrapper around the host `cid:to_string` BIF              |
-| `envelope.erl`        | Activity envelope shape, canonical bytes, time-aware sig verify        |
-| `log.erl`             | Per-actor in-memory append log (open / append / tip / replay / entries) |
-| `registry.erl`        | Pure-functional + gen_server-wrapped registry keyed by Kind             |
-| `pipeline.erl`        | Validation driver + stage_envelope/signature/replay/schema             |
-| `projection.erl`      | Pure projection driver + gen_server-per-projection wrapper             |
-| `outbox.erl`          | Envelope construct + sign + publish orchestrator + broadcast            |
-| `bootstrap.erl`       | Genesis read/build/verify/load + one-call `start/3` kernel bring-up    |
-| `define_registry.erl` | Meta-projection fold for `Create{Define*}` → registry                  |
-| `sandbox.erl`         | `eval_pure/2,3` try/catch envelope for projection folds                |
-| `nx_kernel.erl`       | Long-lived runtime orchestrator (state + gen_server)                    |
-| `http_server.erl`     | route/1,2 + format-aware GET + POST + Accept header content negotiation |
-
-## Genesis bundle
-
-`next/genesis/` contains 31 SX files across 7 sections, all consumed as data
-(read + serialised by `bootstrap:populate_registry`, not eval'd):
-
-- 3 activity-types — Create, Update, Delete
-- 10 object-types — SXArtifact, Note, Tombstone, 6 Define* meta-types, Snapshot
-- 7 projections — activity-log, by-type, by-actor, by-object, actor-state,
-  define-registry, audience-graph
-- 3 validators — envelope-shape, signature, type-schema
-- 3 codecs — dag-cbor, raw, dag-json
-- 2 sig-suites — rsa-sha256-2018, ed25519-2020
-- 3 audience predicates — Public, Followers, Direct
-
-`manifest.sx` is the bundle root, listed in dependency-friendly order.
-
-## Tests
-
-43 test suites, ~560+ assertions. Each script drives `sx_server.exe` via the
-epoch protocol — loads the Erlang substrate, loads relevant kernel modules
-via `code:load_binary` / `erlang-load-module`, then exercises behaviour
-through `erlang-eval-ast`.
-
-Conventions:
-
-- Scripts marked `_pure.sh` exercise pure-functional state.
-- Scripts marked `_server.sh` (or no suffix) exercise gen_server APIs and
-  must inline `start_link` with operations — the Erlang-on-SX scheduler
-  doesn't preserve spawned processes across separate `erlang-eval-ast`
-  invocations.
-- `smoke_*_pure.sh` are end-to-end smoke tests demonstrating the §Step 9
-  proof points without TCP / curl / JSON.
-
-The Erlang-on-SX conformance gate (`bash lib/erlang/conformance.sh`, **729 /
-729**) is the no-regression contract — every commit on `loops/fed-sx-m1`
-preserves it.
-
-## Substrate
-
-Each `.erl` source file is hot-loaded at boot via
-`code:load_binary(Mod, Filename, SourceString)` (Phase 7 BIF). Tests drive
-the runtime via the epoch protocol:
-
-```bash
-printf '(epoch 1)\n(load "lib/erlang/runtime.sx")\n(epoch 2)\n<test-expr>\n' \
-  | hosts/ocaml/_build/default/bin/sx_server.exe
-```
-
-The kernel calls into these host primitives: `crypto:hash/2`,
-`cid:from_bytes/1`, `cid:to_string/1`, `file:read_file/1`, `file:write_file/2`,
-`file:delete/1`, `file:list_dir/1`, `code:load_binary/3`, plus `http:listen/2`
-(the briefing's allowed scope exception, added to `lib/erlang/runtime.sx`).
-
-### Substrate gaps (parked work)
-
-These three gaps block the remaining unchecked deliverables:
-
-1. **Term codec** (`3b`/`3c`) — **all three substrate fixes done 2026-06-05:**
-   `erlang:binary_to_list/1` and `erlang:list_to_binary/1` registered in
-   `lib/erlang/runtime.sx` (iolist-aware); the tokenizer's `$X` branch
-   emits the decimal char code; `atom_to_list/1` and `integer_to_list/1`
-   now return Erlang charlists (standard Erlang semantics) with `list_to_atom`/
-   `list_to_integer` accepting both charlists and SX strings for back-compat.
-   759/759 conformance. The full term-codec primitive set is in place —
-   Step 3b on-disk segment writer can encode arbitrary Erlang activity
-   terms (atoms, ints, binaries, tuples, lists) into byte sequences using
-   only Erlang-native primitives.
-
-2. **SX-source eval bridge** — There's no BIF that lets Erlang call into the
-   SX evaluator on a parsed source string. Blocks evaluating the `:schema` /
-   `:fold` / `:predicate` / `:verify` bodies from the genesis bundle. Erlang-fun
-   stand-ins (`pipeline:stage_schema`, `define_registry:fold`, etc.) prove the
-   API shapes; the bridge would let bundle bodies dispatch through them
-   unchanged.
-
-3. **Dict ↔ proplist marshalling for `http:listen/2`** — **done 2026-06-05.**
-   `er-bif-http-listen` marshals the native server's request dict
-   (`{:method :path :query :headers :body}`) into the proplist shape
-   `[{method, Bin}, {path, Bin}, {query, Bin}, {headers, [{Name, Value}]},
-   {body, Bin}]` that `http_server:route/2` consumes, and converts the
-   handler's response proplist back to `{:status :headers :body}` for the
-   native server to serialise. Helpers (`er-request-dict-to-proplist`,
-   `er-proplist-to-dict`, `er-of-sx-deep`, `er-to-sx-deep`,
-   `er-dict-to-header-proplist`, `er-proplist-fill!`) live alongside the
-   BIF wrapper in `lib/erlang/runtime.sx`. The BIF also spawns the handler
-   into a real Erlang process via `er-spawn-fun` + `er-sched-run-all!`
-   so `self()` / `gen_server:call` work inside route handlers (the kernel
-   and projection gen_servers reach the handler this way). Verified by
-   `next/tests/http_marshal.sh` and the live TCP smoke
-   `next/tests/http_server_tcp.sh` / `http_server_start.sh`. Unblocks
-   `Step 8b-start` (TCP listener spawn) and the curl-driven 9a-tcp / 9b-tcp
-   smoke tests.
-
-### Bringing up the kernel
-
-For tests, `bootstrap:start/3(ActorId, KeySpec, ActorState)` is the
-one-call boot:
-
-```erlang
-KM = <<1,2,3,4>>,
-KS = [{key_id, k1}, {algorithm, ed25519}, {value, KM}],
-AS = [{public_keys, [[{id, k1}, {created, 0}, {value, KM}]]}],
-Pid = bootstrap:start(alice, KS, AS),
-%% nx_kernel + registry populated; you now have a kernel.
-```
-
-The HTTP layer (`http_server`) and `nx_kernel:publish/1` flow through the
-same in-process gen_servers; `http_publish_fold.sh` is the end-to-end proof
-the chain works.
-
-## What's next (when work resumes)
-
-In priority order:
-
-1. **8b-start** — `http_server:start/1` spawns a process hosting `http:listen/2`.
-   (8b-bridge done — see Substrate gap #3.)
-2. **9a-tcp / 9b-tcp** — replace the in-process smoke scripts with curl-driven
-   versions hitting the running server.
-3. **Term codec / on-disk log** — needs either a new BIF or a temp-file
-   workaround; current in-memory log keeps everything functional otherwise.
-4. **SX-source eval bridge** — unlocks real `:schema` / `:fold` body
-   evaluation from the genesis bundle.

next/genesis/activity-types/create.sx

@@ -1,15 +0,0 @@
-;; next/genesis/activity-types/create.sx
-;;
-;; Bootstrap definition of the Create verb per design §3 and §12.2.
-;; Read as data by the bundler (bootstrap.erl) — never evaluated as
-;; code. The :schema and :semantics bodies are SX source; the
-;; validation pipeline (Step 6) and projection scheduler (Step 7)
-;; evaluate them at the appropriate times.
-
-(DefineActivity
-  :name "Create"
-  :doc "Publish a new object. Required for actor onboarding and for\n        every Define* meta-activity. The activity's :object holds\n        the canonical content of the published object."
-  :schema (fn
-    (act)
-    (and (not (nil? (-> act :object))) (string? (-> act :object :type))))
-  :semantics (fn (state act) state))

next/genesis/activity-types/delete.sx

@@ -1,13 +0,0 @@
-;; next/genesis/activity-types/delete.sx
-;;
-;; Bootstrap definition of the Delete verb per design §3 and §12.2.
-;; Read as data by the bundler — never evaluated as code here. The
-;; :schema and :semantics bodies are SX source; the validator
-;; pipeline (Step 6) and projection scheduler (Step 7) evaluate them
-;; at the appropriate times.
-
-(DefineActivity
-  :name "Delete"
-  :doc "Tombstone an existing object. :object is the CID of the\n        target. Projections fold Delete by removing the object from\n        their working indexes; the underlying log line is never\n        erased — durability of the historical record is independent\n        of projection state."
-  :schema (fn (act) (string? (-> act :object)))
-  :semantics (fn (state act) state))

next/genesis/activity-types/update.sx

@@ -1,15 +0,0 @@
-;; next/genesis/activity-types/update.sx
-;;
-;; Bootstrap definition of the Update verb per design §3 and §12.2.
-;; Read as data by the bundler — never evaluated as code here. The
-;; :schema and :semantics bodies are SX source; the validator
-;; pipeline (Step 6) and projection scheduler (Step 7) evaluate them
-;; at the appropriate times.
-
-(DefineActivity
-  :name "Update"
-  :doc "Patch or replace an existing object. :object is the CID of\n        the target; :patch is the field-level edit. Behaviour is\n        delegated to per-object-type semantics — e.g. an Update of a\n        DefineActivity supersedes the prior registry entry; an\n        Update of a Person actor rotates keys via :patch :add-publicKey\n        + :patch :supersede."
-  :schema (fn
-    (act)
-    (and (string? (-> act :object)) (not (nil? (-> act :patch)))))
-  :semantics (fn (state act) state))

next/genesis/audience/direct.sx

@@ -1,14 +0,0 @@
-;; next/genesis/audience/direct.sx
-;;
-;; Direct audience: an actor is a member iff they are
-;; explicitly named in the activity's :to or :cc lists. No
-;; group expansion — true direct addressing only.
-
-(DefineAudience
-  :name "Direct"
-  :doc "Direct-addressing predicate. Tests literal membership\n        in the activity's :to or :cc."
-  :member-of (fn
-    (actor audience)
-    (or
-      (member? actor (-> audience :to))
-      (member? actor (-> audience :cc)))))

next/genesis/audience/followers.sx

@@ -1,14 +0,0 @@
-;; next/genesis/audience/followers.sx
-;;
-;; Followers audience: an actor is a member iff they appear in
-;; the audience-owner's :followers set in the audience-graph
-;; projection. Federation (m2) wires this to peer delivery.
-
-(DefineAudience
-  :name "Followers"
-  :doc "Followers-of-owner predicate. Looks up the\n        audience-graph projection's :followers list for the\n        audience owner and tests membership."
-  :member-of (fn
-    (actor audience)
-    (member?
-      actor
-      (-> (get-projection :audience-graph) (-> audience :owner) :followers))))

next/genesis/audience/public.sx

@@ -1,9 +0,0 @@
-;; next/genesis/audience/public.sx
-;;
-;; Public audience: every actor is a member. Maps to the AP
-;; magic id `https://www.w3.org/ns/activitystreams#Public`.
-
-(DefineAudience
-  :name "Public"
-  :doc "Public audience predicate. Always returns true — every\n        actor on the network is considered a member."
-  :member-of (fn (actor audience) true))

next/genesis/codecs/dag-cbor.sx

@@ -1,13 +0,0 @@
-;; next/genesis/codecs/dag-cbor.sx
-;;
-;; Canonical CBOR encoding per IPLD dag-cbor. Used to compute
-;; envelope canonical bytes for signature coverage and to serialise
-;; the genesis bundle itself. In Erlang-on-SX mode the kernel
-;; dispatches to the host cid:to_string substrate (Step 1b) when
-;; this codec is requested.
-
-(DefineCodec
-  :name "dag-cbor"
-  :doc "Deterministic CBOR with dag-cbor restrictions: sorted\n        map keys, no floats unless required, no indefinite-length\n        items. The canonical wire format for fed-sx artifacts."
-  :encode (fn (term) (host-codec :dag-cbor :encode term))
-  :decode (fn (bytes) (host-codec :dag-cbor :decode bytes)))

next/genesis/codecs/dag-json.sx

@@ -1,12 +0,0 @@
-;; next/genesis/codecs/dag-json.sx
-;;
-;; JSON encoding with dag-json restrictions per IPLD: sorted map
-;; keys, no NaN / Infinity, no comments, CIDs as `{"/": "..."}`.
-;; Used as the human-readable wire format for ActivityPub interop
-;; (JSON-LD over dag-json).
-
-(DefineCodec
-  :name "dag-json"
-  :doc "Deterministic JSON with dag-json restrictions. Sorted\n        keys, CIDs as the {\"/\": \"...\"} object. Used by the\n        HTTP server (Step 8) for application/json responses."
-  :encode (fn (term) (host-codec :dag-json :encode term))
-  :decode (fn (bytes) (host-codec :dag-json :decode bytes)))

next/genesis/codecs/raw.sx

@@ -1,12 +0,0 @@
-;; next/genesis/codecs/raw.sx
-;;
-;; Identity codec — input bytes pass through unchanged in both
-;; directions. Used for already-encoded payloads and for binary
-;; artifacts (images, archives) whose CID is computed over the
-;; raw bytes directly.
-
-(DefineCodec
-  :name "raw"
-  :doc "Identity codec. The CID's multicodec byte is 0x55.\n        :encode and :decode return their input unchanged."
-  :encode (fn (bytes) bytes)
-  :decode (fn (bytes) bytes))

next/genesis/manifest.sx

@@ -1,46 +0,0 @@
-;; next/genesis/manifest.sx
-;;
-;; Genesis bundle root per design §12.2. Lists every definition file
-;; that gets packed into the bundle. The bundler (bootstrap.erl)
-;; walks this manifest, reads each referenced file, parses its
-;; top-level form, and inserts it into the bundle dict at the
-;; appropriate section path.
-;;
-;; The bundle CID is the content-address of the resulting dag-cbor
-;; (or v1 stand-in) blob over the assembled dict. That CID is
-;; baked into the kernel at build time and re-verified on startup
-;; per design §12.3.
-;;
-;; Section values are bare parenthesised paths (data lists, not
-;; function calls) — the manifest is consumed by `parse`, not
-;; `eval`. Empty sections are written as `()`.
-
-(GenesisManifest
-  :version "0.0.1"
-  :kernel-version "1.0.0-m1"
-  :activity-types ("activity-types/create.sx"
-    "activity-types/update.sx"
-    "activity-types/delete.sx")
-  :object-types ("object-types/sx-artifact.sx"
-    "object-types/note.sx"
-    "object-types/tombstone.sx"
-    "object-types/define-activity.sx"
-    "object-types/define-object.sx"
-    "object-types/define-projection.sx"
-    "object-types/define-validator.sx"
-    "object-types/define-codec.sx"
-    "object-types/define-sig-suite.sx"
-    "object-types/snapshot.sx")
-  :projections ("projections/activity-log.sx"
-    "projections/by-type.sx"
-    "projections/by-actor.sx"
-    "projections/by-object.sx"
-    "projections/actor-state.sx"
-    "projections/define-registry.sx"
-    "projections/audience-graph.sx")
-  :validators ("validators/envelope-shape.sx"
-    "validators/signature.sx"
-    "validators/type-schema.sx")
-  :codecs ("codecs/dag-cbor.sx" "codecs/raw.sx" "codecs/dag-json.sx")
-  :sig-suites ("sig-suites/rsa-sha256-2018.sx" "sig-suites/ed25519-2020.sx")
-  :audience ("audience/public.sx" "audience/followers.sx" "audience/direct.sx"))

next/genesis/object-types/define-activity.sx

@@ -1,12 +0,0 @@
-;; next/genesis/object-types/define-activity.sx
-;;
-;; Meta-object that registers a new activity verb. Published as
-;; Create{DefineActivity{...}}; the define-registry projection
-;; folds it into the activity-types registry. Per design §5.
-
-(DefineObject
-  :name "DefineActivity"
-  :doc "Activity-type registration. :name is the verb (e.g.\n        \"Pin\"); :schema is an SX predicate over activity\n        envelopes; :semantics is an optional state-fold body."
-  :schema (fn
-    (obj)
-    (and (string? (-> obj :name)) (not (nil? (-> obj :schema))))))

next/genesis/object-types/define-codec.sx

@@ -1,15 +0,0 @@
-;; next/genesis/object-types/define-codec.sx
-;;
-;; Meta-object that registers a content codec — an encode/decode
-;; pair. The bootstrap bundle ships dag-cbor, raw, and dag-json
-;; codecs; new codecs can be added via Create{DefineCodec{...}}.
-
-(DefineObject
-  :name "DefineCodec"
-  :doc "Codec registration. :name identifies the codec ('dag-cbor',\n        'raw', 'dag-json', ...); :encode and :decode are the\n        SX bodies the kernel calls when serialising / parsing\n        artifacts under this codec."
-  :schema (fn
-    (obj)
-    (and
-      (string? (-> obj :name))
-      (not (nil? (-> obj :encode)))
-      (not (nil? (-> obj :decode))))))

next/genesis/object-types/define-object.sx

@@ -1,12 +0,0 @@
-;; next/genesis/object-types/define-object.sx
-;;
-;; Meta-object that registers a new object-type. Bootstrap-level —
-;; runtime registration of new object types (e.g. DefineSubscription
-;; in the Step 9b smoke test) flows through this.
-
-(DefineObject
-  :name "DefineObject"
-  :doc "Object-type registration. :name is the type tag (e.g.\n        \"PinSpec\"); :schema is an SX predicate over object\n        forms of that type."
-  :schema (fn
-    (obj)
-    (and (string? (-> obj :name)) (not (nil? (-> obj :schema))))))

next/genesis/object-types/define-projection.sx

@@ -1,16 +0,0 @@
-;; next/genesis/object-types/define-projection.sx
-;;
-;; Meta-object that registers a new projection. The projection
-;; scheduler (Step 7) spawns one gen_server per registered
-;; projection and feeds activities through its :fold body in
-;; sandbox mode.
-
-(DefineObject
-  :name "DefineProjection"
-  :doc "Projection registration. :name is the projection key;\n        :initial-state is the empty state value; :fold is the\n        pure (state activity) -> state function evaluated in\n        sandbox mode per activity."
-  :schema (fn
-    (obj)
-    (and
-      (string? (-> obj :name))
-      (not (nil? (-> obj :initial-state)))
-      (not (nil? (-> obj :fold))))))

next/genesis/object-types/define-sig-suite.sx

@@ -1,12 +0,0 @@
-;; next/genesis/object-types/define-sig-suite.sx
-;;
-;; Meta-object that registers a signature suite. Bootstrap ships
-;; rsa-sha256-2018 and ed25519-2020; the suite name maps an
-;; algorithm to a :verify body and a :key-format predicate.
-
-(DefineObject
-  :name "DefineSigSuite"
-  :doc "Signature suite registration. :name identifies the suite\n        ('rsa-sha256-2018', 'ed25519-2020', ...); :verify is the\n        SX (canonical-bytes signature key) -> bool body; the\n        envelope-signature validator dispatches by suite name."
-  :schema (fn
-    (obj)
-    (and (string? (-> obj :name)) (not (nil? (-> obj :verify))))))

next/genesis/object-types/define-validator.sx

@@ -1,12 +0,0 @@
-;; next/genesis/object-types/define-validator.sx
-;;
-;; Meta-object that registers a validator predicate. The validation
-;; pipeline (Step 6) consults registered validators by name when
-;; running its stages.
-
-(DefineObject
-  :name "DefineValidator"
-  :doc "Validator registration. :name is the validator key (e.g.\n        \"envelope-shape\"); :predicate is the SX (activity) ->\n        ok|{error, R} body."
-  :schema (fn
-    (obj)
-    (and (string? (-> obj :name)) (not (nil? (-> obj :predicate))))))

next/genesis/object-types/note.sx

@@ -1,10 +0,0 @@
-;; next/genesis/object-types/note.sx
-;;
-;; Short message intended for an audience, ActivityPub-Note-compatible.
-;; Used by the Step 9b reactive smoke test (Note tagged "smoketest"
-;; matches the Topic subscription).
-
-(DefineObject
-  :name "Note"
-  :doc "Short authored message. :content is the body text;\n        :tags is a list of subscription-routable tags."
-  :schema (fn (obj) (string? (-> obj :content))))

next/genesis/object-types/snapshot.sx

@@ -1,13 +0,0 @@
-;; next/genesis/object-types/snapshot.sx
-;;
-;; Projection state checkpoint. The projection scheduler emits
-;; Snapshot{projection-name, state-cid, log-seq} periodically;
-;; cold starts read the most recent Snapshot and replay only
-;; activities after :log-seq. Per design §10.5.
-
-(DefineObject
-  :name "Snapshot"
-  :doc "Projection-state checkpoint. :projection-name identifies\n        the projection; :state-cid is the content-address of\n        the snapshotted state value; :log-seq is the activity\n        sequence number the snapshot was taken at."
-  :schema (fn
-    (obj)
-    (and (string? (-> obj :projection-name)) (string? (-> obj :state-cid)))))

next/genesis/object-types/sx-artifact.sx

@@ -1,10 +0,0 @@
-;; next/genesis/object-types/sx-artifact.sx
-;;
-;; Content-addressed SX source — a library, component, or
-;; executable form published via Create{SXArtifact{...}}.
-;; Consumers reference an artifact by its CID. Per design §3.4.
-
-(DefineObject
-  :name "SXArtifact"
-  :doc "Published SX source. :source carries the form text;\n        :language is optional ('sx' by default); :imports lists\n        CIDs the artifact depends on."
-  :schema (fn (obj) (string? (-> obj :source))))

next/genesis/object-types/tombstone.sx

@@ -1,9 +0,0 @@
-;; next/genesis/object-types/tombstone.sx
-;;
-;; Replacement for an object that has been Delete'd. Lets projection
-;; folds keep a marker without retaining the deleted content.
-
-(DefineObject
-  :name "Tombstone"
-  :doc "Marker for a deleted object. :former-cid carries the CID\n        of the object that was removed. Projections fold Tombstone\n        by replacing the cached entry (not by omitting it)."
-  :schema (fn (obj) (string? (-> obj :former-cid))))

next/genesis/projections/activity-log.sx

@@ -1,11 +0,0 @@
-;; next/genesis/projections/activity-log.sx
-;;
-;; Identity projection: stores every activity by its CID. The
-;; base ledger every other projection could be re-derived from
-;; if needed. Per design §10.2.
-
-(DefineProjection
-  :name "activity-log"
-  :doc "Maps activity CID to the full envelope. Every activity\n        flows through; no filter. State is the CID-keyed dict."
-  :initial-state {}
-  :fold (fn (state act) (assoc state (-> act :cid) act)))

next/genesis/projections/actor-state.sx

@@ -1,26 +0,0 @@
-;; next/genesis/projections/actor-state.sx
-;;
-;; Per-actor live state: publicKeys (with history per design §9.6),
-;; profile fields (preferredUsername, summary, ...), follower/
-;; following counts. Powers the actor doc endpoint and the
-;; time-aware signature verification in envelope:verify_signature/2.
-
-(DefineProjection
-  :name "actor-state"
-  :doc "Actor-id -> {publicKeys, profile, followers, following}.\n        Updated by Create{Person|Service|Group}, Update (key\n        rotation, profile edits), Move (federation migration)."
-  :initial-state {}
-  :fold (fn
-    (state act)
-    (let
-      ((aid (-> act :actor)) (t (-> act :type)))
-      (cond
-        (= t "Create")
-        (assoc state aid (or (-> act :object) {}))
-        (= t "Update")
-        (assoc
-          state
-          aid
-          (merge
-            (or (get state aid) {})
-            (or (-> act :patch) {})))
-        :else state))))

next/genesis/projections/audience-graph.sx

@@ -1,25 +0,0 @@
-;; next/genesis/projections/audience-graph.sx
-;;
-;; Per-actor follow / follower graph and audience caches. Folded
-;; from Follow / Accept / Reject / Undo{Follow}. Used by the
-;; activity router to expand :to / :cc audiences (Public,
-;; Followers, Direct) into concrete recipient sets. Per design §16.
-
-(DefineProjection
-  :name "audience-graph"
-  :doc "Actor-id -> {following, followers, pending} sets.\n        Updated by Follow / Accept / Reject / Undo. Federation\n        (m2) wires this projection to the delivery queue."
-  :initial-state {}
-  :fold (fn
-    (state act)
-    (let
-      ((t (-> act :type)))
-      (cond
-        (= t "Follow")
-        state
-        (= t "Accept")
-        state
-        (= t "Reject")
-        state
-        (= t "Undo")
-        state
-        :else state))))

next/genesis/projections/by-actor.sx

@@ -1,15 +0,0 @@
-;; next/genesis/projections/by-actor.sx
-;;
-;; Index of activity CIDs grouped by :actor. Maps actor-id to a
-;; list of CIDs in append order. Powers the per-actor outbox
-;; listing (Step 8) without re-scanning the full log.
-
-(DefineProjection
-  :name "by-actor"
-  :doc "Actor-id -> list of activity CIDs (append order)."
-  :initial-state {}
-  :fold (fn
-    (state act)
-    (let
-      ((a (-> act :actor)) (cid (-> act :cid)))
-      (assoc state a (append (or (get state a) (list)) (list cid))))))

next/genesis/projections/by-object.sx

@@ -1,22 +0,0 @@
-;; next/genesis/projections/by-object.sx
-;;
-;; Index of activities that reference each :object CID. Maps
-;; object-CID to the list of activity CIDs that target it
-;; (Update / Delete / Announce / etc.). Used for "show me
-;; everything that happened to X" queries.
-
-(DefineProjection
-  :name "by-object"
-  :doc "Object CID -> list of activity CIDs that target it."
-  :initial-state {}
-  :fold (fn
-    (state act)
-    (let
-      ((obj-cid (-> act :object)) (cid (-> act :cid)))
-      (if
-        (string? obj-cid)
-        (assoc
-          state
-          obj-cid
-          (append (or (get state obj-cid) (list)) (list cid)))
-        state))))

next/genesis/projections/by-type.sx

@@ -1,15 +0,0 @@
-;; next/genesis/projections/by-type.sx
-;;
-;; Index of activity CIDs grouped by :type. Maps type-name to a
-;; list of CIDs in append order. Used by the outbox listing
-;; endpoints (Step 8) for type-filtered pagination.
-
-(DefineProjection
-  :name "by-type"
-  :doc "Type-name -> list of activity CIDs (append order)."
-  :initial-state {}
-  :fold (fn
-    (state act)
-    (let
-      ((t (-> act :type)) (cid (-> act :cid)))
-      (assoc state t (append (or (get state t) (list)) (list cid))))))

next/genesis/projections/define-registry.sx

@@ -1,33 +0,0 @@
-;; next/genesis/projections/define-registry.sx
-;;
-;; The meta-projection: folds Create{Define*{...}} activities into
-;; the kernel registry. Resolves the chicken-and-egg circle —
-;; bootstrap.erl populates the registry directly at startup from
-;; the genesis bundle, and from then on define-registry's fold
-;; keeps it current as new Define* activities arrive. Per design §5.
-
-(DefineProjection
-  :name "define-registry"
-  :doc "Maps {kind, name} -> definition entry. Folded from\n        Create{DefineActivity|DefineObject|DefineProjection|\n        DefineValidator|DefineCodec|DefineSigSuite|...}. Kind is\n        derived from the inner :object :type tag."
-  :initial-state {}
-  :fold (fn
-    (state act)
-    (let
-      ((obj (-> act :object)) (otype (-> act :object :type)))
-      (cond
-        (= (-> act :type) "Create")
-        (cond
-          (= otype "DefineActivity")
-          (assoc-in state (list :activity-types (-> obj :name)) obj)
-          (= otype "DefineObject")
-          (assoc-in state (list :object-types (-> obj :name)) obj)
-          (= otype "DefineProjection")
-          (assoc-in state (list :projections (-> obj :name)) obj)
-          (= otype "DefineValidator")
-          (assoc-in state (list :validators (-> obj :name)) obj)
-          (= otype "DefineCodec")
-          (assoc-in state (list :codecs (-> obj :name)) obj)
-          (= otype "DefineSigSuite")
-          (assoc-in state (list :sig-suites (-> obj :name)) obj)
-          :else state)
-        :else state))))

next/genesis/sig-suites/ed25519-2020.sx

@@ -1,11 +0,0 @@
-;; next/genesis/sig-suites/ed25519-2020.sx
-;;
-;; W3C Verifiable Credential signature suite — Ed25519 over
-;; canonical bytes, key material in multibase. Default suite
-;; for fed-sx actors per design §9.
-
-(DefineSigSuite
-  :name "ed25519-2020"
-  :doc "Ed25519 verification. Key carries publicKeyMultibase.\n        :verify takes canonical-bytes + signature + key and\n        returns bool. Real verification deferred to m2 once\n        crypto:verify_ed25519/3 BIF lands; v1 stand-in returns\n        false to defer all Ed25519-signed activities."
-  :verify (fn (canonical-bytes signature key) false)
-  :key-format (fn (key-doc) (string? (-> key-doc :publicKeyMultibase))))

next/genesis/sig-suites/rsa-sha256-2018.sx

@@ -1,11 +0,0 @@
-;; next/genesis/sig-suites/rsa-sha256-2018.sx
-;;
-;; W3C Verifiable Credential signature suite — RSA-SHA256 over
-;; canonical bytes, key material in PEM. Compatible with
-;; Mastodon's HTTP-Signatures / Linked-Data-Signatures-2017.
-
-(DefineSigSuite
-  :name "rsa-sha256-2018"
-  :doc "RSA-SHA256 verification. Key carries publicKeyPem.\n        :verify takes canonical-bytes + signature + key and\n        returns bool. Real verification deferred to m2 once\n        crypto:verify_rsa/3 BIF lands; v1 stand-in returns\n        false to defer all RSA-signed activities."
-  :verify (fn (canonical-bytes signature key) false)
-  :key-format (fn (key-doc) (string? (-> key-doc :publicKeyPem))))