Add :- to op table (prec 1200 xfx); enable assert/asserta/assertz with rule terms

- parser.sx: add (":-" 1200 "xfx") to pl-op-table so (head :- body) parses
  inside paren expressions (parens reset prec to 1200, allowing xfx match)
- parser.sx: extend pl-token-op to accept "op" token type, not just "atom",
  since the tokenizer emits :- as {:type "op" :value ":-"}
- tests/assert_rules.sx: 15 new tests covering assertz/asserta with rule
  terms, conjunction in rule body, recursive rules, and ordering
- conformance.sh: wire in assert_rules suite
- 456 → 471 tests, all passing

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/prolog/conformance.sh

@@ -38,6 +38,7 @@ SUITES=(
   "set_predicates:lib/prolog/tests/set_predicates.sx:pl-set-predicates-tests-run!"
   "char_predicates:lib/prolog/tests/char_predicates.sx:pl-char-predicates-tests-run!"
   "io_predicates:lib/prolog/tests/io_predicates.sx:pl-io-predicates-tests-run!"
+  "assert_rules:lib/prolog/tests/assert_rules.sx:pl-assert-rules-tests-run!"
 )
 
 SCRIPT='(epoch 1)

lib/prolog/parser.sx

@@ -101,6 +101,7 @@
     (list "-" 500 "yfx")
     (list "*" 400 "yfx")
     (list "/" 400 "yfx")
+    (list ":-" 1200 "xfx")
     (list "mod" 400 "yfx")))
 
 (define
@@ -126,7 +127,7 @@
           (let
             ((info (pl-op-lookup ",")))
             (if (nil? info) nil (cons "," info))))
-        ((= ty "atom")
+        ((or (= ty "atom") (= ty "op"))
           (let
             ((info (pl-op-lookup vv)))
             (if (nil? info) nil (cons vv info))))

lib/prolog/scoreboard.json

@@ -1,7 +1,7 @@
 {
-  "total_passed": 456,
+  "total_passed": 471,
   "total_failed": 0,
-  "total": 456,
-  "suites": {"parse":{"passed":25,"total":25,"failed":0},"unify":{"passed":47,"total":47,"failed":0},"clausedb":{"passed":14,"total":14,"failed":0},"solve":{"passed":62,"total":62,"failed":0},"operators":{"passed":19,"total":19,"failed":0},"dynamic":{"passed":11,"total":11,"failed":0},"findall":{"passed":11,"total":11,"failed":0},"term_inspect":{"passed":14,"total":14,"failed":0},"append":{"passed":6,"total":6,"failed":0},"reverse":{"passed":6,"total":6,"failed":0},"member":{"passed":7,"total":7,"failed":0},"nqueens":{"passed":6,"total":6,"failed":0},"family":{"passed":10,"total":10,"failed":0},"atoms":{"passed":34,"total":34,"failed":0},"query_api":{"passed":16,"total":16,"failed":0},"iso_predicates":{"passed":29,"total":29,"failed":0},"meta_predicates":{"passed":25,"total":25,"failed":0},"list_predicates":{"passed":33,"total":33,"failed":0},"meta_call":{"passed":15,"total":15,"failed":0},"set_predicates":{"passed":15,"total":15,"failed":0},"char_predicates":{"passed":27,"total":27,"failed":0},"io_predicates":{"passed":24,"total":24,"failed":0}},
-  "generated": "2026-04-25T13:00:15+00:00"
+  "total": 471,
+  "suites": {"parse":{"passed":25,"total":25,"failed":0},"unify":{"passed":47,"total":47,"failed":0},"clausedb":{"passed":14,"total":14,"failed":0},"solve":{"passed":62,"total":62,"failed":0},"operators":{"passed":19,"total":19,"failed":0},"dynamic":{"passed":11,"total":11,"failed":0},"findall":{"passed":11,"total":11,"failed":0},"term_inspect":{"passed":14,"total":14,"failed":0},"append":{"passed":6,"total":6,"failed":0},"reverse":{"passed":6,"total":6,"failed":0},"member":{"passed":7,"total":7,"failed":0},"nqueens":{"passed":6,"total":6,"failed":0},"family":{"passed":10,"total":10,"failed":0},"atoms":{"passed":34,"total":34,"failed":0},"query_api":{"passed":16,"total":16,"failed":0},"iso_predicates":{"passed":29,"total":29,"failed":0},"meta_predicates":{"passed":25,"total":25,"failed":0},"list_predicates":{"passed":33,"total":33,"failed":0},"meta_call":{"passed":15,"total":15,"failed":0},"set_predicates":{"passed":15,"total":15,"failed":0},"char_predicates":{"passed":27,"total":27,"failed":0},"io_predicates":{"passed":24,"total":24,"failed":0},"assert_rules":{"passed":15,"total":15,"failed":0}},
+  "generated": "2026-04-25T13:21:37+00:00"
 }

lib/prolog/scoreboard.md

@@ -1,7 +1,7 @@
 # Prolog scoreboard
 
-**456 / 456 passing** (0 failure(s)).
-Generated 2026-04-25T13:00:15+00:00.
+**471 / 471 passing** (0 failure(s)).
+Generated 2026-04-25T13:21:37+00:00.
 
 | Suite | Passed | Total | Status |
 |-------|--------|-------|--------|
@@ -27,6 +27,7 @@ Generated 2026-04-25T13:00:15+00:00.
 | set_predicates | 15 | 15 | ok |
 | char_predicates | 27 | 27 | ok |
 | io_predicates | 24 | 24 | ok |
+| assert_rules | 15 | 15 | ok |
 
 Run `bash lib/prolog/conformance.sh` to refresh. Override the binary
 with `SX_SERVER=path/to/sx_server.exe bash …`.

lib/prolog/tests/assert_rules.sx

@@ -0,0 +1,215 @@
+;; lib/prolog/tests/assert_rules.sx — assert/assertz/asserta with rule terms (head :- body)
+;; Tests that :- is in the op table (prec 1200 xfx) and pl-build-clause handles rule form.
+
+(define pl-ar-test-count 0)
+(define pl-ar-test-pass 0)
+(define pl-ar-test-fail 0)
+(define pl-ar-test-failures (list))
+
+(define
+  pl-ar-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! pl-ar-test-count (+ pl-ar-test-count 1))
+      (if
+        (= got expected)
+        (set! pl-ar-test-pass (+ pl-ar-test-pass 1))
+        (begin
+          (set! pl-ar-test-fail (+ pl-ar-test-fail 1))
+          (append!
+            pl-ar-test-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+(define
+  pl-ar-goal
+  (fn
+    (src env)
+    (pl-instantiate (nth (first (pl-parse (str "g :- " src "."))) 2) env)))
+
+;; ── DB1: assertz a simple rule then query ──────────────────────────
+(define pl-ar-db1 (pl-mk-db))
+
+(pl-solve-once!
+  pl-ar-db1
+  (pl-ar-goal "assertz((double(X, Y) :- Y is X * 2))" {})
+  (pl-mk-trail))
+
+(pl-ar-test!
+  "assertz rule: double(3, Y) succeeds"
+  (pl-solve-once!
+    pl-ar-db1
+    (pl-ar-goal "double(3, Y)" {})
+    (pl-mk-trail))
+  true)
+
+(define pl-ar-env1 {})
+(pl-solve-once!
+  pl-ar-db1
+  (pl-ar-goal "double(3, Y)" pl-ar-env1)
+  (pl-mk-trail))
+
+(pl-ar-test!
+  "assertz rule: double(3, Y) binds Y to 6"
+  (pl-num-val (pl-walk-deep (dict-get pl-ar-env1 "Y")))
+  6)
+
+(define pl-ar-env1b {})
+(pl-solve-once!
+  pl-ar-db1
+  (pl-ar-goal "double(10, Y)" pl-ar-env1b)
+  (pl-mk-trail))
+
+(pl-ar-test!
+  "assertz rule: double(10, Y) yields 20"
+  (pl-num-val (pl-walk-deep (dict-get pl-ar-env1b "Y")))
+  20)
+
+;; ── DB2: assert a rule with multiple facts, count solutions ─────────
+(define pl-ar-db2 (pl-mk-db))
+
+(pl-solve-once!
+  pl-ar-db2
+  (pl-ar-goal "assert(fact(a))" {})
+  (pl-mk-trail))
+(pl-solve-once!
+  pl-ar-db2
+  (pl-ar-goal "assert(fact(b))" {})
+  (pl-mk-trail))
+(pl-solve-once!
+  pl-ar-db2
+  (pl-ar-goal "assertz((copy(X) :- fact(X)))" {})
+  (pl-mk-trail))
+
+(pl-ar-test!
+  "rule copy/1 using fact/1: 2 solutions"
+  (pl-solve-count! pl-ar-db2 (pl-ar-goal "copy(X)" {}) (pl-mk-trail))
+  2)
+
+(define pl-ar-env2a {})
+(pl-solve-once! pl-ar-db2 (pl-ar-goal "copy(X)" pl-ar-env2a) (pl-mk-trail))
+
+(pl-ar-test!
+  "rule copy/1: first solution is a"
+  (pl-atom-name (pl-walk-deep (dict-get pl-ar-env2a "X")))
+  "a")
+
+;; ── DB3: asserta rule is tried before existing clauses ─────────────
+(define pl-ar-db3 (pl-mk-db))
+
+(pl-solve-once!
+  pl-ar-db3
+  (pl-ar-goal "assert(ord(a))" {})
+  (pl-mk-trail))
+(pl-solve-once!
+  pl-ar-db3
+  (pl-ar-goal "asserta((ord(b) :- true))" {})
+  (pl-mk-trail))
+
+(define pl-ar-env3 {})
+(pl-solve-once! pl-ar-db3 (pl-ar-goal "ord(X)" pl-ar-env3) (pl-mk-trail))
+
+(pl-ar-test!
+  "asserta rule ord(b) is tried before ord(a)"
+  (pl-atom-name (pl-walk-deep (dict-get pl-ar-env3 "X")))
+  "b")
+
+(pl-ar-test!
+  "asserta: total solutions for ord/1 is 2"
+  (pl-solve-count! pl-ar-db3 (pl-ar-goal "ord(X)" {}) (pl-mk-trail))
+  2)
+
+;; ── DB4: rule with conjunction in body ─────────────────────────────
+(define pl-ar-db4 (pl-mk-db))
+
+(pl-solve-once!
+  pl-ar-db4
+  (pl-ar-goal "assert(num(1))" {})
+  (pl-mk-trail))
+(pl-solve-once!
+  pl-ar-db4
+  (pl-ar-goal "assert(num(2))" {})
+  (pl-mk-trail))
+(pl-solve-once!
+  pl-ar-db4
+  (pl-ar-goal "assertz((big(X) :- num(X), X > 1))" {})
+  (pl-mk-trail))
+
+(pl-ar-test!
+  "conjunction in rule body: big(1) fails"
+  (pl-solve-once! pl-ar-db4 (pl-ar-goal "big(1)" {}) (pl-mk-trail))
+  false)
+
+(pl-ar-test!
+  "conjunction in rule body: big(2) succeeds"
+  (pl-solve-once! pl-ar-db4 (pl-ar-goal "big(2)" {}) (pl-mk-trail))
+  true)
+
+;; ── DB5: recursive rule ─────────────────────────────────────────────
+(define pl-ar-db5 (pl-mk-db))
+
+(pl-solve-once!
+  pl-ar-db5
+  (pl-ar-goal "assert((nat(0) :- true))" {})
+  (pl-mk-trail))
+(pl-solve-once!
+  pl-ar-db5
+  (pl-ar-goal "assertz((nat(s(X)) :- nat(X)))" {})
+  (pl-mk-trail))
+
+(pl-ar-test!
+  "recursive rule: nat(0) succeeds"
+  (pl-solve-once! pl-ar-db5 (pl-ar-goal "nat(0)" {}) (pl-mk-trail))
+  true)
+
+(pl-ar-test!
+  "recursive rule: nat(s(0)) succeeds"
+  (pl-solve-once!
+    pl-ar-db5
+    (pl-ar-goal "nat(s(0))" {})
+    (pl-mk-trail))
+  true)
+
+(pl-ar-test!
+  "recursive rule: nat(s(s(0))) succeeds"
+  (pl-solve-once!
+    pl-ar-db5
+    (pl-ar-goal "nat(s(s(0)))" {})
+    (pl-mk-trail))
+  true)
+
+(pl-ar-test!
+  "recursive rule: nat(bad) fails"
+  (pl-solve-once! pl-ar-db5 (pl-ar-goal "nat(bad)" {}) (pl-mk-trail))
+  false)
+
+;; ── DB6: rule with true body (explicit) ────────────────────────────
+(define pl-ar-db6 (pl-mk-db))
+
+(pl-solve-once!
+  pl-ar-db6
+  (pl-ar-goal "assertz((always(X) :- true))" {})
+  (pl-mk-trail))
+(pl-solve-once!
+  pl-ar-db6
+  (pl-ar-goal "assert(always(extra))" {})
+  (pl-mk-trail))
+
+(pl-ar-test!
+  "rule body=true: always(foo) succeeds"
+  (pl-solve-once!
+    pl-ar-db6
+    (pl-ar-goal "always(foo)" {})
+    (pl-mk-trail))
+  true)
+
+(pl-ar-test!
+  "rule body=true: always/1 has 2 clauses (1 rule + 1 fact)"
+  (pl-solve-count!
+    pl-ar-db6
+    (pl-ar-goal "always(X)" {})
+    (pl-mk-trail))
+  2)
+
+;; ── Runner ──────────────────────────────────────────────────────────
+(define pl-assert-rules-tests-run! (fn () {:failed pl-ar-test-fail :passed pl-ar-test-pass :total pl-ar-test-count :failures pl-ar-test-failures}))

lib/prolog/tests/list_predicates.sx

@@ -53,12 +53,18 @@
 
 (pl-lp-test!
   "==(f(a,b), f(a,b)) succeeds"
-  (pl-solve-once! pl-lp-db (pl-lp-goal "==(f(a,b), f(a,b))" {}) (pl-mk-trail))
+  (pl-solve-once!
+    pl-lp-db
+    (pl-lp-goal "==(f(a,b), f(a,b))" {})
+    (pl-mk-trail))
   true)
 
 (pl-lp-test!
   "==(f(a,b), f(a,c)) fails"
-  (pl-solve-once! pl-lp-db (pl-lp-goal "==(f(a,b), f(a,c))" {}) (pl-mk-trail))
+  (pl-solve-once!
+    pl-lp-db
+    (pl-lp-goal "==(f(a,b), f(a,c))" {})
+    (pl-mk-trail))
   false)
 
 ;; unbound var vs atom: fails (different tags)
@@ -74,7 +80,9 @@
   "==(X, X) succeeds (same runtime var)"
   (pl-solve-once!
     pl-lp-db
-    (pl-instantiate (nth (first (pl-parse "g :- ==(X, X).")) 2) pl-lp-env-same-var)
+    (pl-instantiate
+      (nth (first (pl-parse "g :- ==(X, X).")) 2)
+      pl-lp-env-same-var)
     (pl-mk-trail))
   true)
 
@@ -166,7 +174,10 @@
 
 (pl-lp-test!
   "numlist(5, 3, L) fails (Low > High)"
-  (pl-solve-once! pl-lp-db (pl-lp-goal "numlist(5, 3, L)" {}) (pl-mk-trail))
+  (pl-solve-once!
+    pl-lp-db
+    (pl-lp-goal "numlist(5, 3, L)" {})
+    (pl-mk-trail))
   false)
 
 ;; ── atomic_list_concat/2 ───────────────────────────────────────────
@@ -321,10 +332,4 @@
   (pl-format-term (pl-walk-deep (dict-get pl-lp-env-del3 "R")))
   "[]")
 
-(define pl-list-predicates-tests-run!
-  (fn
-    ()
-    {:failed pl-lp-test-fail
-      :passed pl-lp-test-pass
-      :total pl-lp-test-count
-      :failures pl-lp-test-failures}))
+(define pl-list-predicates-tests-run! (fn () {:failed pl-lp-test-fail :passed pl-lp-test-pass :total pl-lp-test-count :failures pl-lp-test-failures}))