merge loops/prolog: complete Prolog-on-SX implementation

590 tests passing across 29 suites. Brings in: parser, runtime,
query API, compiler, conformance harness, integration suite, and
hs-bridge (combined hook + factory styles).

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

lib/prolog/hs-bridge.sx

@@ -1,21 +1,84 @@
-;; lib/prolog/hs-bridge.sx — Prolog ↔ _hyperscript bridge
+;; lib/prolog/hs-bridge.sx — Prolog ↔ Hyperscript bridge
 ;;
-;; Installs the prolog hook into the hyperscript runtime so that
-;; hyperscript scripts can call:
+;; Two complementary integration styles:
 ;;
-;;   prolog(db, "goal(args)")   → true  (at least one solution)
-;;                              → false (no solution)
+;; 1. Hook style — for `prolog(db, "goal(args)")` call syntax in Hyperscript:
+;;      (pl-install-hs-hook!)   ;; call once at startup
+;;    Requires lib/hyperscript/runtime.sx (provides hs-set-prolog-hook!)
 ;;
-;; Usage:
-;;   (pl-install-hs-hook!)   ;; call once at startup, after loading both libs
+;; 2. Factory style — for named conditions like `when allowed(user, action)`:
+;;      (define allowed (pl-hs-predicate/2 pl-db "allowed"))
+;;    No parser/compiler changes needed: Hyperscript compiles
+;;    `allowed(user, action)` to `(allowed user action)` — a plain SX call.
 ;;
-;; Depends on:
-;;   lib/hyperscript/runtime.sx  — provides hs-set-prolog-hook!
-;;   lib/prolog/runtime.sx       — provides pl-query-one (Phase 3+)
+;; Requires tokenizer.sx, parser.sx, runtime.sx, query.sx loaded first.
+
+;; --- Hook style ---
 
 (define
   pl-install-hs-hook!
   (fn
     ()
     (hs-set-prolog-hook!
-      (fn (db goal) (not (= nil (pl-query-one db goal)))))))
+      (fn (db goal) (not (= nil (pl-query-one db goal)))))))
+
+;; --- Factory style ---
+
+;; Test whether a ground Prolog goal succeeds against db.
+;; Returns true/false (not a solution dict).
+(define
+  pl-hs-query
+  (fn (db goal-str) (not (nil? (pl-query-one db goal-str)))))
+
+;; Build a Prolog goal string from a predicate name and arg list.
+;; SX values: strings/keywords pass through; numbers are stringified via str.
+(define
+  pl-hs-build-goal
+  (fn
+    (pred-name args)
+    (str pred-name "(" (join ", " (map (fn (a) (str a)) args)) ")")))
+
+;; Return a 1-arg SX function that succeeds iff pred(a) holds in db.
+(define
+  pl-hs-predicate/1
+  (fn
+    (db pred-name)
+    (fn (a) (pl-hs-query db (pl-hs-build-goal pred-name (list a))))))
+
+;; Return a 2-arg SX function that succeeds iff pred(a, b) holds in db.
+(define
+  pl-hs-predicate/2
+  (fn
+    (db pred-name)
+    (fn (a b) (pl-hs-query db (pl-hs-build-goal pred-name (list a b))))))
+
+;; Return a 3-arg SX function that succeeds iff pred(a, b, c) holds in db.
+(define
+  pl-hs-predicate/3
+  (fn
+    (db pred-name)
+    (fn (a b c) (pl-hs-query db (pl-hs-build-goal pred-name (list a b c))))))
+
+;; Install every predicate in install-list as a named SX function backed by db.
+;; install-list: list of (name arity) pairs.
+;; Returns a dict {name → fn} for the caller to destructure.
+(define
+  pl-hs-install
+  (fn
+    (db install-list)
+    (reduce
+      (fn
+        (acc entry)
+        (let
+          ((pred-name (first entry)) (arity (nth entry 1)))
+          (dict-set!
+            acc
+            pred-name
+            (cond
+              ((= arity 1) (pl-hs-predicate/1 db pred-name))
+              ((= arity 2) (pl-hs-predicate/2 db pred-name))
+              ((= arity 3) (pl-hs-predicate/3 db pred-name))
+              (true (fn (a b) false))))
+          acc))
+      {}
+      install-list)))