Progress log: assert_rules + :- op, 471/471

plans/prolog-on-sx.md

@@ -66,7 +66,7 @@ Representation choices (finalise in phase 1, document here):
 
 ### Phase 4 — operator table + more built-ins (next run)
 - [x] Operator table parsing (prefix/infix/postfix, precedence, assoc) — `pl-op-table` (15 entries: `, ; -> = \= is < > =< >= + - * / mod`); precedence-climbing parser via `pp-parse-primary` + `pp-parse-term-prec` + `pp-parse-op-rhs`. Parens override precedence. Args inside compounds parsed at 999 so `,` stays as separator. xfx/xfy/yfx supported; prefix/postfix deferred (so `-5` still tokenises as bare atom + num as before). Comparison built-ins `</2 >/2 =</2 >=/2` added. New `tests/operators.sx` 19 tests cover assoc/precedence/parens + solver via infix.
-- [x] `assert/1`, `asserta/1`, `assertz/1`, `retract/1` — `assert` aliases `assertz`. Helpers `pl-rt-to-ast` (deep-walk + replace runtime vars with `_G<id>` parse markers) + `pl-build-clause` (detect `:-` head). `assertz` uses `pl-db-add!`; `asserta` uses new `pl-db-prepend!`. `retract` walks goal, looks up by functor/arity, tries each clause via unification, removes first match by index (`pl-list-without`). 11 tests in `tests/dynamic.sx`. Rule-asserts deferred — `:-` not in op table yet, so only fact-shaped clauses for now.
+- [x] `assert/1`, `asserta/1`, `assertz/1`, `retract/1` — `assert` aliases `assertz`. Helpers `pl-rt-to-ast` (deep-walk + replace runtime vars with `_G<id>` parse markers) + `pl-build-clause` (detect `:-` head). `assertz` uses `pl-db-add!`; `asserta` uses new `pl-db-prepend!`. `retract` walks goal, looks up by functor/arity, tries each clause via unification, removes first match by index (`pl-list-without`). 11 tests in `tests/dynamic.sx`. Rule-asserts now work — `:-` added to op table (prec 1200 xfx) with fix to `pl-token-op` accepting `"op"` token type. 15 tests in `tests/assert_rules.sx`.
 - [x] `findall/3`, `bagof/3`, `setof/3` — shared `pl-collect-solutions` runs the goal in a fresh cut-box, deep-copies the template (via `pl-deep-copy` with var-map for shared-var preservation) on each success, returns false to backtrack, then restores trail. `findall` always succeeds with a (possibly empty) list. `bagof` fails on empty. `setof` builds a string-keyed dict via `pl-format-term` for sort+dedupe (via `keys` + `sort`), fails on empty. Existential `^` deferred (operator). 11 tests in `tests/findall.sx`.
 - [x] `copy_term/2`, `functor/3`, `arg/3`, `=../2` — `copy_term/2` reuses `pl-deep-copy` with a fresh var-map (preserves source aliasing). `functor/3` handles 4 modes: compound→{name, arity}, atom→{atom, 0}, num→{num, 0}, var with ground name+arity→constructed term (`pl-make-fresh-args` for compound case). `arg/3` extracts 1-indexed arg from compound. **`=../2` deferred** — the tokenizer treats `.` as the clause terminator unconditionally, so `=..` lexes as `=` + `.` + `.`; needs special-case lex (or surface syntax via a different name). 14 tests in `tests/term_inspect.sx`.
 - [x] String/atom predicates
@@ -88,6 +88,7 @@ Representation choices (finalise in phase 1, document here):
 
 _Newest first. Agent appends on every commit._
 
+- 2026-04-25 — `:-` operator + assert with rules: added `(list ":-" 1200 "xfx")` to `pl-op-table`; fixed `pl-token-op` to accept `"op"` token type (tokenizer emits `:-` as `"op"`, not `"atom"`). `pl-build-clause` already handled `("compound" ":-" ...)`. `assert((head :- body))` now works for facts+rules. 15 tests in `tests/assert_rules.sx`. Total **471** (+15).
 - 2026-04-25 — IO/term predicates: `term_to_atom/2` (bidirectional: format term or parse atom), `term_string/2` (alias), `with_output_to/2` (atom/string sinks — saves/restores `pl-output-buffer`), `writeln/1`, `format/1` (~n/~t/~~), `format/2` (~w/~a/~d pull from arg list). 24 tests in `tests/io_predicates.sx`. Total **456** (+24).
 - 2026-04-25 — Char predicates: `char_type/2` (9 modes: alpha/alnum/digit/digit(N)/space/white/upper(L)/lower(U)/ascii(C)/punct), `upcase_atom/2`, `downcase_atom/2`, `string_upper/2`, `string_lower/2`. 10 helpers using `char-code`/`char-from-code` SX primitives. 27 tests in `tests/char_predicates.sx`. Total **432** (+27).
 - 2026-04-25 — Set/fold predicates: `foldl/4` (CPS fold-left, threads accumulator via `pl-apply-goal`), `list_to_set/2` (dedup preserving first-occurrence), `intersection/3`, `subtract/3`, `union/3` (all via `pl-struct-eq?`). 3 new helpers, 15 tests in `tests/set_predicates.sx`. Total **405** (+15).