prolog-query SX API: pl-load + pl-query-all + pl-query-one + pl-query (+16 tests)

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

plans/prolog-on-sx.md

@@ -72,7 +72,7 @@ Representation choices (finalise in phase 1, document here):
 - [x] String/atom predicates
 
 ### Phase 5 — Hyperscript integration
-- [ ] `prolog-query` primitive callable from SX/Hyperscript
+- [x] `prolog-query` primitive callable from SX/Hyperscript
 - [ ] Hyperscript DSL: `when allowed(user, :edit) then …`
 - [ ] Integration suite
 
@@ -88,6 +88,7 @@ Representation choices (finalise in phase 1, document here):
 
 _Newest first. Agent appends on every commit._
 
+- 2026-04-25 — `prolog-query` SX API (`lib/prolog/query.sx`). New public API layer: `pl-load source-str → db`, `pl-query-all db query-str → list of solution dicts`, `pl-query-one db query-str → dict or nil`, `pl-query src query → list` (convenience). Each solution dict maps variable name strings to their formatted term strings. Var names extracted from pre-instantiation parse AST. Trail is marked before solve and reset after to ensure clean state. 16 tests in `tests/query_api.sx` cover fact lookup, no-solution, boolean queries, multi-var, recursive rules, is/2 built-in, query-one, convenience form. Total **288** (+16).
 - 2026-04-25 — String/atom predicates. Type-test predicates: `var/1`, `nonvar/1`, `atom/1`, `number/1`, `integer/1`, `float/1` (always-fail), `compound/1`, `callable/1`, `atomic/1`, `is_list/1`. String/atom operations: `atom_length/2`, `atom_concat/3` (3 modes: both-ground, result+first, result+second), `atom_chars/2` (bidirectional), `atom_codes/2` (bidirectional), `char_code/2` (bidirectional), `number_codes/2`, `number_chars/2`. 7 helper functions in runtime.sx (`pl-list-to-prolog`, `pl-proper-list?`, `pl-prolog-list-to-sx`, `pl-solve-atom-concat!`, `pl-solve-atom-chars!`, `pl-solve-atom-codes!`, `pl-solve-char-code!`). 34 tests in `tests/atoms.sx`. Total **272** (+34).
 - 2026-04-25 — `copy_term/2` + `functor/3` + `arg/3` (term inspection). `copy_term` is a one-line dispatch to existing `pl-deep-copy`. `functor/3` is bidirectional — decomposes a bound compound/atom/num into name+arity OR constructs from ground name+arity (atom+positive-arity → compound with N anonymous fresh args via `pl-make-fresh-args`; arity 0 → atom/num). `arg/3` extracts 1-indexed arg with bounds-fail. New helper `pl-solve-eq2!` for paired-unification with shared trail-undo. 14 tests in `tests/term_inspect.sx`. Total **238** (+14). `=..` deferred — `.` always tokenizes as clause terminator; needs special lexer case.
 - 2026-04-25 — `findall/3` + `bagof/3` + `setof/3`. Shared collector `pl-collect-solutions` runs the goal in a fresh cut-box, deep-copies the template per success (`pl-deep-copy` walks term, allocates fresh runtime vars via shared var-map so co-occurrences keep aliasing), returns false to keep backtracking, then `pl-trail-undo-to!` to clean up. `findall` always builds a list. `bagof` fails on empty. `setof` uses a `pl-format-term`-keyed dict + SX `sort` for dedupe + ordering. New `tests/findall.sx` 11 tests. Total **224** (+11). Existential `^` deferred — needs operator.