fed-sx-m1: Step 3b substrate fix #2 — $X char literals decode to char code in tokenizer (+12 eval, 750/750)

lib/erlang/scoreboard.json

@@ -1,11 +1,11 @@
 {
   "language": "erlang",
-  "total_pass": 738,
+  "total_pass": 750,
-  "total": 738,
+  "total": 750,
   "suites": [
     {"name":"tokenize","pass":62,"total":62,"status":"ok"},
     {"name":"parse","pass":52,"total":52,"status":"ok"},
-    {"name":"eval","pass":385,"total":385,"status":"ok"},
+    {"name":"eval","pass":397,"total":397,"status":"ok"},
     {"name":"runtime","pass":93,"total":93,"status":"ok"},
     {"name":"ring","pass":4,"total":4,"status":"ok"},
     {"name":"ping-pong","pass":4,"total":4,"status":"ok"},

lib/erlang/scoreboard.md

@@ -1,12 +1,12 @@
 # Erlang-on-SX Scoreboard
 
-**Total: 738 / 738 tests passing**
+**Total: 750 / 750 tests passing**
 
 |  | Suite | Pass | Total |
 |---|---|---|---|
 | ✅ | tokenize | 62 | 62 |
 | ✅ | parse | 52 | 52 |
-| ✅ | eval | 385 | 385 |
+| ✅ | eval | 397 | 397 |
 | ✅ | runtime | 93 | 93 |
 | ✅ | ring | 4 | 4 |
 | ✅ | ping-pong | 4 | 4 |

lib/erlang/tests/eval.sx

@@ -1341,6 +1341,23 @@
   (get (nth (get er-rt-cap-result :elements) 4) :name) "true")
 
 
+
+;; ── $X char literals (Step 3b substrate fix 2026-06-04) ──────────
+(er-eval-test "char $A" (ev "$A") 65)
+(er-eval-test "char $a" (ev "$a") 97)
+(er-eval-test "char $0 is digit, not escape-NUL" (ev "$0") 48)
+(er-eval-test "char $\\n is newline (10)" (ev "$\\n") 10)
+(er-eval-test "char $\\t is tab (9)" (ev "$\\t") 9)
+(er-eval-test "char $\\r is CR (13)" (ev "$\\r") 13)
+(er-eval-test "char $\\s is space (32)" (ev "$\\s") 32)
+(er-eval-test "char $\\0 is NUL (0)" (ev "$\\0") 0)
+(er-eval-test "char $\\\\ is backslash (92)" (ev "$\\\\") 92)
+(er-eval-test "[$h,$i] head is 104" (ev "hd([$h, $i])") 104)
+(er-eval-test "list_to_binary char-list -> bytes"
+  (ev "byte_size(list_to_binary([$f, $e, $d]))") 3)
+(er-eval-test "list_to_binary char-list round-trip"
+  (nm (ev "list_to_binary([$h, $i]) =:= <<104, 105>>")) "true")
+
 (define
   er-eval-test-summary
   (str "eval " er-eval-test-pass "/" er-eval-test-count))

lib/erlang/tokenizer.sx

@@ -229,13 +229,37 @@
                 (= ch "$")
                 (do
                   (er-advance! 1)
-                  (if
+                  ;; Emit the char's decimal code as the integer token value
-                    (and (< pos src-len) (= (er-cur) "\\"))
+                  ;; (was: raw "$X" text — parse-number then returned nil).
-                    (do
+                  (let
-                      (er-advance! 1)
+                    ((code (cond
-                      (when (< pos src-len) (er-advance! 1)))
+                       (>= pos src-len) 0
-                    (when (< pos src-len) (er-advance! 1)))
+                       (= (er-cur) "\\")
-                  (er-emit! "integer" (slice src start pos) start)
+                         (do
+                           (er-advance! 1)
+                           (let ((esc (if (< pos src-len) (er-cur) "")))
+                             (when (< pos src-len) (er-advance! 1))
+                             (cond
+                               (= esc "n")  10
+                               (= esc "t")  9
+                               (= esc "r")  13
+                               (= esc "s")  32
+                               (= esc "b")  8
+                               (= esc "e")  27
+                               (= esc "f")  12
+                               (= esc "v")  11
+                               (= esc "d")  127
+                               (= esc "0")  0
+                               (= esc "\\")  92
+                               (= esc "\"") 34
+                               (= esc "'")  39
+                               (= esc "")   0
+                               :else (char->integer (nth (string->list esc) 0)))))
+                       :else
+                         (let ((c (er-cur)))
+                           (er-advance! 1)
+                           (char->integer (nth (string->list c) 0))))))
+                    (er-emit! "integer" (str code) start))
                   (scan!))
                 (er-lower? ch)
                 (do

next/README.md

@@ -103,16 +103,16 @@ The kernel calls into these host primitives: `crypto:hash/2`,
 
 These three gaps block the remaining unchecked deliverables:
 
-1. **Term codec** (`3b`/`3c`) — **byte-level path resolved 2026-06-04:**
+1. **Term codec** (`3b`/`3c`) — **substrate fixes #1 + #2 done 2026-06-04:**
-   `erlang:binary_to_list/1` and `erlang:list_to_binary/1` are now registered
+   `erlang:binary_to_list/1` and `erlang:list_to_binary/1` are registered
-   in `lib/erlang/runtime.sx` (738/738 conformance, +9 ffi tests). `list_to_binary`
+   in `lib/erlang/runtime.sx` (`list_to_binary` is iolist-aware); the
-   is iolist-aware (`[1, <<2,3>>, [4, [5]]]` → `<<1,2,3,4,5>>`); round-trip
+   tokenizer's `$X` branch now emits the decimal char code, so `[$h, $i | T]`
-   `list_to_binary(binary_to_list(B)) =:= B` holds. Step 3b on-disk segment
+   patterns and `list_to_binary([$f,$e,$d])` work end-to-end. 750/750
-   writer is unblocked if it uses byte ints directly. Still parked:
+   conformance, +9 ffi + +12 eval tests. Step 3b on-disk segment writer
-   `atom_to_list`/`integer_to_list` return SX-strings (an opaque OCaml-string
+   has a complete byte-level term ↔ binary path. Still parked (low priority
-   type), not Erlang charlists; `$X` char literals decode to `nil` in
+   for Milestone 1): `atom_to_list`/`integer_to_list` return SX-strings
-   `parse-number`. Both still block code that wants Erlang-idiomatic
+   (an opaque OCaml-string type), not Erlang charlists — only blocks code
-   `[$h,$i | T]` patterns on atom/integer names.
+   that wants charlist arithmetic on atom/integer names.
 
 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` /

plans/fed-sx-milestone-1.md

@@ -200,7 +200,7 @@ verify_signature(Activity, ActorState) ->
 - [ ] **3b** — *Parked behind substrate gap (see Blockers below).* Term codec + on-disk persistence: serializer/parser writing each activity as a JSONL-style line; restart-resumes-tip from the segment file.
 - [ ] **3c** — Segment rotation at size threshold + gen_server-mediated concurrent appends.
 
-**Blockers (Step 3b) — byte-level path resolved 2026-06-04:** `binary_to_list/1` and `list_to_binary/1` are now registered Erlang BIFs in `lib/erlang/runtime.sx` (Step 3b substrate fix, +9 ffi tests, 738/738 conformance). `list_to_binary` is iolist-aware: accepts nested cons of integer bytes (0-255) and/or binaries; `binary_to_list` returns a proper Erlang charlist of integers. Round-trip verified: `list_to_binary(binary_to_list(B)) =:= B`. On-disk segment writer (3b) can now build segment bytes from `[Header, IoListPayload]` and reconstruct on read — option (c) of the original workaround menu is now cheap. Still parked: `atom_to_list/1`/`integer_to_list/1` return SX strings rather than Erlang charlists, and `$X` char literals decode to `nil` in `parse-number`. Neither blocks the on-disk format if the encoding uses byte ints directly (no string→list coercion); both still block code that wants to write Erlang-idiomatic `[$h,$i | T]` patterns. 3b on-disk implementation is unblocked; revisit the remaining two gaps if a downstream Step requires charlist arithmetic on atom/integer names.
+**Blockers (Step 3b) — byte-level path resolved 2026-06-04:** `binary_to_list/1` and `list_to_binary/1` are now registered Erlang BIFs in `lib/erlang/runtime.sx` (Step 3b substrate fix, +9 ffi tests, 738/738 conformance). `list_to_binary` is iolist-aware: accepts nested cons of integer bytes (0-255) and/or binaries; `binary_to_list` returns a proper Erlang charlist of integers. Round-trip verified: `list_to_binary(binary_to_list(B)) =:= B`. On-disk segment writer (3b) can now build segment bytes from `[Header, IoListPayload]` and reconstruct on read — option (c) of the original workaround menu is now cheap. `$X` char literals now decode correctly **as of 2026-06-04**: the Erlang tokenizer's `(= ch "$")` branch (`lib/erlang/tokenizer.sx`) now emits the decimal char code as the token value instead of the raw `$X` text (which `parse-number` couldn't decode → nil). Plain chars use `char->integer` of the first char; the standard escape table (`\n=10 \t=9 \r=13 \s=32 \b=8 \e=27 \f=12 \v=11 \d=127 \0=0 \\=92 \"=34 \'=39`) handles `$\X` forms. So `[$h, $i | T]` patterns and `list_to_binary([$f,$e,$d])` both work end-to-end. +12 eval tests, 750/750. Combined with 3b's `binary_to_list`/`list_to_binary`, Erlang code can now read/write byte sequences and string-shaped char lists fluently. Still parked: `atom_to_list/1`/`integer_to_list/1` return SX strings rather than Erlang charlists — only blocks code that wants to do `[$0+N | _]` arithmetic on integer-to-string output or `[Lower | _]` on atom names; downstream Steps in this milestone don't need it.
 
 **Deliverables:**
 
@@ -1003,6 +1003,7 @@ A few things still under-specified; resolve as work begins.
 Newest first. One line per sub-deliverable commit. Erlang conformance gate
 (`bash lib/erlang/conformance.sh`) must remain 729/729 on every entry.
 
+- **2026-06-04** — Step 3b substrate fix #2: `$X` char-literal decoding. Patched the Erlang tokenizer's `(= ch "$")` branch in `lib/erlang/tokenizer.sx` to emit the decimal char code as the integer token value instead of the raw `$X` source text (which `parse-number` couldn't decode → nil). Plain `$c` uses `char->integer` of the first char; `$\C` consults the standard Erlang escape table (`\n=10 \t=9 \r=13 \s=32 \b=8 \e=27 \f=12 \v=11 \d=127 \0=0 \\=92 \"=34 \'=39`). End-of-file after `$` decodes to 0 defensively. Probes: `$A→65`, `$0→48`, `$\n→10`, `$\\→92`, `[$h,$i]` → cons of 104/105, `list_to_binary([$f,$e,$d])` → `<<102,101,100>>`. +12 eval tests (single chars, each escape, list/binary composition with previous BIFs). Combined with substrate fix #1, Erlang code in fed-sx-m1 can now write `[$h, $i | T]` patterns AND construct/deconstruct binaries — a full term-codec primitive set. Erlang conformance **750/750** (eval 385→397). Plan Blockers note updated; remaining `atom_to_list`/`integer_to_list` charlist gap noted as low-priority for Milestone 1.
 - **2026-06-04** — Step 3b substrate fix: registered `erlang:binary_to_list/1` and `erlang:list_to_binary/1` in `lib/erlang/runtime.sx` — the byte-level half of the term-codec gap. `binary_to_list` returns a proper Erlang charlist (`er-mk-cons` chain of byte ints). `list_to_binary` is iolist-aware via a recursive `er-iolist-walk!` that accepts nil / cons / binary / integer 0-255 and flattens nested iolists (e.g. `[1, <<2,3>>, [4, [5]]]` → `<<1,2,3,4,5>>`); out-of-range bytes or non-iolist elements raise `error:badarg`. Round-trip verified: `list_to_binary(binary_to_list(B)) =:= B`. +9 ffi tests (length, hd, empty→[], flat byte_size, nested-iolist, round-trip, 3 badarg paths). On-disk segment writer (3b) now has a complete `[Header | IoListPayload] → Binary` path; the remaining two substrate gaps (`atom_to_list`/`integer_to_list` as Erlang charlists, `$X` char-literal decoding) are still parked but no longer block 3b implementation if the encoding uses byte ints directly. Erlang conformance **738/738** (ffi 28→37). Plan Blockers note for Step 3b updated to reflect the partial resolution.
 - **2026-05-28** — Step 4f-consolidate: `bootstrap:start/3(ActorId, KeySpec, ActorState)` brings up the full kernel substrate in one call — starts the registry gen_server, populates it from the canonical genesis bundle (31 entries across 7 kinds), then starts nx_kernel. Returns the kernel Pid (gen_server convention in this port returns raw Pid not `{ok, Pid}`). Tests verify whereis(nx_kernel), per-kind counts (3/10/7/3/3/2/3), registry lookup of a known entry (`create`), publish + log_tip advance. `next/tests/bootstrap_start.sh` 10/10. Erlang conformance 729/729.
 - **2026-05-28** — Step 7d-pure: `next/kernel/sandbox.erl` — `eval_pure/2(Fun, Arg)` and `eval_pure/3(Fun, Activity, State)`. try/catch envelope returns `{ok, Result}` on success and `{error, {Class, Reason}}` for each of the three exception classes (throw, error, exit). The 3-arity variant matches the projection-fold shape so the scheduler can wrap fold bodies. Port note: this Erlang implementation catches by explicit class names rather than the open `Class:Reason` pattern — wrappers enumerate `throw:Reason / error:Reason / exit:Reason` explicitly. Real gas budget + IO denial + env-stripping lands with SX-source eval; the wrapper API doesn't change. `next/tests/sandbox_eval.sh` 13/13. Erlang conformance 729/729.