ISO predicates: succ/2 + plus/3 + between/3 + length/2 + last/2 + nth0/3 + nth1/3 + max/min arith (+29 tests, 317 total)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

lib/prolog/tests/iso_predicates.sx

@@ -0,0 +1,320 @@
+;; lib/prolog/tests/iso_predicates.sx — succ/2, plus/3, between/3, length/2, last/2, nth0/3, nth1/3, max/min arith
+
+(define pl-ip-test-count 0)
+(define pl-ip-test-pass 0)
+(define pl-ip-test-fail 0)
+(define pl-ip-test-failures (list))
+
+(define
+  pl-ip-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! pl-ip-test-count (+ pl-ip-test-count 1))
+      (if
+        (= got expected)
+        (set! pl-ip-test-pass (+ pl-ip-test-pass 1))
+        (begin
+          (set! pl-ip-test-fail (+ pl-ip-test-fail 1))
+          (append!
+            pl-ip-test-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+(define
+  pl-ip-goal
+  (fn
+    (src env)
+    (pl-instantiate (nth (first (pl-parse (str "g :- " src "."))) 2) env)))
+
+(define pl-ip-db (pl-mk-db))
+
+;; ── succ/2 ──
+
+(define pl-ip-env-s1 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "succ(3, X)" pl-ip-env-s1)
+  (pl-mk-trail))
+(pl-ip-test!
+  "succ(3, X) → X=4"
+  (pl-num-val (pl-walk-deep (dict-get pl-ip-env-s1 "X")))
+  4)
+
+(define pl-ip-env-s2 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "succ(0, X)" pl-ip-env-s2)
+  (pl-mk-trail))
+(pl-ip-test!
+  "succ(0, X) → X=1"
+  (pl-num-val (pl-walk-deep (dict-get pl-ip-env-s2 "X")))
+  1)
+
+(define pl-ip-env-s3 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "succ(X, 5)" pl-ip-env-s3)
+  (pl-mk-trail))
+(pl-ip-test!
+  "succ(X, 5) → X=4"
+  (pl-num-val (pl-walk-deep (dict-get pl-ip-env-s3 "X")))
+  4)
+
+(pl-ip-test!
+  "succ(X, 0) fails"
+  (pl-solve-once!
+    pl-ip-db
+    (pl-ip-goal "succ(X, 0)" {})
+    (pl-mk-trail))
+  false)
+
+;; ── plus/3 ──
+
+(define pl-ip-env-p1 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "plus(2, 3, X)" pl-ip-env-p1)
+  (pl-mk-trail))
+(pl-ip-test!
+  "plus(2, 3, X) → X=5"
+  (pl-num-val (pl-walk-deep (dict-get pl-ip-env-p1 "X")))
+  5)
+
+(define pl-ip-env-p2 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "plus(2, X, 7)" pl-ip-env-p2)
+  (pl-mk-trail))
+(pl-ip-test!
+  "plus(2, X, 7) → X=5"
+  (pl-num-val (pl-walk-deep (dict-get pl-ip-env-p2 "X")))
+  5)
+
+(define pl-ip-env-p3 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "plus(X, 3, 7)" pl-ip-env-p3)
+  (pl-mk-trail))
+(pl-ip-test!
+  "plus(X, 3, 7) → X=4"
+  (pl-num-val (pl-walk-deep (dict-get pl-ip-env-p3 "X")))
+  4)
+
+(pl-ip-test!
+  "plus(0, 0, 0) succeeds"
+  (pl-solve-once!
+    pl-ip-db
+    (pl-ip-goal "plus(0, 0, 0)" {})
+    (pl-mk-trail))
+  true)
+
+;; ── between/3 ──
+
+(pl-ip-test!
+  "between(1, 3, X): 3 solutions"
+  (pl-solve-count!
+    pl-ip-db
+    (pl-ip-goal "between(1, 3, X)" {})
+    (pl-mk-trail))
+  3)
+
+(pl-ip-test!
+  "between(1, 3, 2) succeeds"
+  (pl-solve-once!
+    pl-ip-db
+    (pl-ip-goal "between(1, 3, 2)" {})
+    (pl-mk-trail))
+  true)
+
+(pl-ip-test!
+  "between(1, 3, 5) fails"
+  (pl-solve-once!
+    pl-ip-db
+    (pl-ip-goal "between(1, 3, 5)" {})
+    (pl-mk-trail))
+  false)
+
+(pl-ip-test!
+  "between(5, 3, X): 0 solutions (empty range)"
+  (pl-solve-count!
+    pl-ip-db
+    (pl-ip-goal "between(5, 3, X)" {})
+    (pl-mk-trail))
+  0)
+
+(define pl-ip-env-b1 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "between(1, 5, X)" pl-ip-env-b1)
+  (pl-mk-trail))
+(pl-ip-test!
+  "between(1, 5, X): first solution X=1"
+  (pl-num-val (pl-walk-deep (dict-get pl-ip-env-b1 "X")))
+  1)
+
+(pl-ip-test!
+  "between + condition: between(1,5,X), X > 3 → 2 solutions"
+  (pl-solve-count!
+    pl-ip-db
+    (pl-ip-goal "between(1, 5, X), X > 3" {})
+    (pl-mk-trail))
+  2)
+
+;; ── length/2 ──
+
+(define pl-ip-env-l1 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "length([1,2,3], N)" pl-ip-env-l1)
+  (pl-mk-trail))
+(pl-ip-test!
+  "length([1,2,3], N) → N=3"
+  (pl-num-val (pl-walk-deep (dict-get pl-ip-env-l1 "N")))
+  3)
+
+(define pl-ip-env-l2 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "length([], N)" pl-ip-env-l2)
+  (pl-mk-trail))
+(pl-ip-test!
+  "length([], N) → N=0"
+  (pl-num-val (pl-walk-deep (dict-get pl-ip-env-l2 "N")))
+  0)
+
+(pl-ip-test!
+  "length([a,b], 2) check succeeds"
+  (pl-solve-once!
+    pl-ip-db
+    (pl-ip-goal "length([a,b], 2)" {})
+    (pl-mk-trail))
+  true)
+
+(define pl-ip-env-l3 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "length(L, 3)" pl-ip-env-l3)
+  (pl-mk-trail))
+(pl-ip-test!
+  "length(L, 3): L is a list of length 3"
+  (pl-solve-once!
+    pl-ip-db
+    (pl-ip-goal "length(L, 3), is_list(L)" pl-ip-env-l3)
+    (pl-mk-trail))
+  true)
+
+;; ── last/2 ──
+
+(define pl-ip-env-la1 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "last([1,2,3], X)" pl-ip-env-la1)
+  (pl-mk-trail))
+(pl-ip-test!
+  "last([1,2,3], X) → X=3"
+  (pl-num-val (pl-walk-deep (dict-get pl-ip-env-la1 "X")))
+  3)
+
+(define pl-ip-env-la2 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "last([a], X)" pl-ip-env-la2)
+  (pl-mk-trail))
+(pl-ip-test!
+  "last([a], X) → X=a"
+  (pl-atom-name (pl-walk-deep (dict-get pl-ip-env-la2 "X")))
+  "a")
+
+(pl-ip-test!
+  "last([], X) fails"
+  (pl-solve-once!
+    pl-ip-db
+    (pl-ip-goal "last([], X)" {})
+    (pl-mk-trail))
+  false)
+
+;; ── nth0/3 ──
+
+(define pl-ip-env-n0 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "nth0(0, [a,b,c], X)" pl-ip-env-n0)
+  (pl-mk-trail))
+(pl-ip-test!
+  "nth0(0, [a,b,c], X) → X=a"
+  (pl-atom-name (pl-walk-deep (dict-get pl-ip-env-n0 "X")))
+  "a")
+
+(define pl-ip-env-n1 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "nth0(2, [a,b,c], X)" pl-ip-env-n1)
+  (pl-mk-trail))
+(pl-ip-test!
+  "nth0(2, [a,b,c], X) → X=c"
+  (pl-atom-name (pl-walk-deep (dict-get pl-ip-env-n1 "X")))
+  "c")
+
+(pl-ip-test!
+  "nth0(5, [a,b,c], X) fails"
+  (pl-solve-once!
+    pl-ip-db
+    (pl-ip-goal "nth0(5, [a,b,c], X)" {})
+    (pl-mk-trail))
+  false)
+
+;; ── nth1/3 ──
+
+(define pl-ip-env-n1a {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "nth1(1, [a,b,c], X)" pl-ip-env-n1a)
+  (pl-mk-trail))
+(pl-ip-test!
+  "nth1(1, [a,b,c], X) → X=a"
+  (pl-atom-name (pl-walk-deep (dict-get pl-ip-env-n1a "X")))
+  "a")
+
+(define pl-ip-env-n1b {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "nth1(3, [a,b,c], X)" pl-ip-env-n1b)
+  (pl-mk-trail))
+(pl-ip-test!
+  "nth1(3, [a,b,c], X) → X=c"
+  (pl-atom-name (pl-walk-deep (dict-get pl-ip-env-n1b "X")))
+  "c")
+
+;; ── max/min in arithmetic ──
+
+(define pl-ip-env-m1 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "X is max(3, 5)" pl-ip-env-m1)
+  (pl-mk-trail))
+(pl-ip-test!
+  "X is max(3, 5) → X=5"
+  (pl-num-val (pl-walk-deep (dict-get pl-ip-env-m1 "X")))
+  5)
+
+(define pl-ip-env-m2 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "X is min(3, 5)" pl-ip-env-m2)
+  (pl-mk-trail))
+(pl-ip-test!
+  "X is min(3, 5) → X=3"
+  (pl-num-val (pl-walk-deep (dict-get pl-ip-env-m2 "X")))
+  3)
+
+(define pl-ip-env-m3 {})
+(pl-solve-once!
+  pl-ip-db
+  (pl-ip-goal "X is max(7, 2) + min(1, 4)" pl-ip-env-m3)
+  (pl-mk-trail))
+(pl-ip-test!
+  "X is max(7,2) + min(1,4) → X=8"
+  (pl-num-val (pl-walk-deep (dict-get pl-ip-env-m3 "X")))
+  8)
+
+(define pl-iso-predicates-tests-run! (fn () {:failed pl-ip-test-fail :passed pl-ip-test-pass :total pl-ip-test-count :failures pl-ip-test-failures}))