Long-form per-release changelog for yopl. The repo's README.md carries cliff-notes for users skimming GitHub; this page is the canonical history with internal-change context, motivation, and credits.

Rule compiler and JS-native bridge library. The largest feature release since the 1.2.0 ESM repackage. Rules can now be written declaratively via a tagged-template DSL; the IR is reusable across front-ends; a new predicate library bridges yopl unification to plain JS objects, arrays, Map, Set, and Date.

• Rule compiler (src/compile/). Pure-data IR with 5 Term kinds (var, wildcard, literal, cons, compound) and 4 Goal kinds (call, cut, fail, js), plus Clause and Rule. Lowering is the only place that knows the runtime rule shape; front-ends emit IR.
  • Per-clause front-end (compile/clause/). Tagged-template DSL:

    rule('member', 2)(clause`(X, [X | _])`, clause`(X, [_ | T]) :- member(X, T)`);

    Uppercase identifiers are logic Variables; _ is the wildcard; [X | T] is cons-list sugar; ${...} interpolates IR or auto-wraps primitives / functions.
  • Validator (compile/validate.js) catches arity-mismatch, call-arity-mismatch, undeclared-var, duplicate-rule, and (opt-in) unresolved-rule.
  • All five existing rule modules (system, comp, math, bits, logic) are dogfooded through the compiler.
• Lit-walker. Lit(value) lowers per activation, descending into plain objects and arrays and substituting nested IR nodes (Var, Wild, Cons, Compound, Lit) with the activation's fresh logic Variables. So Lit({age: Var('A')}) doubles as a pattern matcher and a constructor. Maps, Sets, Dates, and Wrap-wrapped values pass through verbatim. IR detection is gated on the closed IR_KINDS set so user objects with a domain kind field aren't misread.
• unifyOpts/3 (in system.js). unifyOpts(X, Y, Opts) runs deep6's unification with a per-call options bag ({openObjects, openArrays, openMaps, openSets, circular, loose, ignoreFunctions, signedZero, symbols}). The env's baseline options is restored before the goal returns. From clause source, pass options as ${Lit({openArrays: true})}.
• yopl/rules/native.js — JS-native bridge predicates split out from system.js so the latter stays focused on generic logic-programming.
  • Type tests — isArray, isMap, isSet, isDate. (isArray moved out of system.js to live with its siblings.)
  • Array — arrayList(A, L) (bidir array ↔ cons list), arrayGet(A, I, X) (forward indexed lookup), arraySet(A, I, X, A2) (immutable single-index override; in-bounds replace or append-at-end), arrayLength(A, N).
  • Map — mapEntries(M, Es) (bidir; both-bound case is order-independent), mapGet(M, K, V), mapHas(M, K).
  • Set — setItems(S, Items) (bidir), setHas(S, X).
  • Date — dateTimestamp(D, Ms) (bidir; TZ-agnostic), dateComponents(D, C) and dateComponentsUTC(D, C) (bidir; component bag {year, month, day, hour, minute, second, ms}, month 0-based; pairs cleanly with the Lit-walker for partial-bag pattern matching).
• bitOr reverse-mode identities. bitOr(0, Y, Z) and bitOr(X, 0, Z) now answer Z = Y / Z = X respectively via (0, Y, Y) and (X, 0, X) fact clauses, mirroring the existing bitXor identity-fact pattern. forwardTernary cuts only on the modes it actually resolves (verify-all-3 + forward) so identity facts can fire on under-specified reverse queries without duplicating forward solutions.
• IR re-exports. yopl/compile/ir.js re-exports open, soft, and _ (also as any) from deep6 for fine-grained per-value match control: Lit(open({tag: 'a'})) locks subset matching regardless of env options; Lit(soft({...})) extends both sides.
• Var() mints anonymous Variables. Var() (no name argument) returns {kind: 'var', name: Symbol()} — useful for IR fragments built in JS code that need a guaranteed-unique identity. Mirrors deep6's variable() idiom.
• Bench scaffold (bench/). Top-level bench-{proof-loop,drivers, inline-goals}.js scripts using nano-benchmark as a dev dep. Run via npm run bench (one-shot) or npm run bench:watch.
• Regex-based clause tokenizer modelled on stream-json's sticky- regex lexing — the V8 RegExp engine eats whole lexemes in native code rather than the JS interpreter walking char-by-char. Functionally equivalent to the previous lexer; faster on the multi-KB inputs the upcoming Prolog front-end will need.
• Design docs. New dev-docs/compiler-ir.md (IR design, decisions, Lit-walker, unifyOpts/3, practical patterns) and dev-docs/native-objects.md (Array / Map / Set / Date roadmap, what's shipped vs postponed).
• Junk audit. Removed AUTHORS (single-line duplicate of package.json#author) and CODEBASE.md (redundant with ARCHITECTURE.md).

Test count grew from 152 → 258 across the IR / lower / validate / clause front-end / native bridges / Lit-walker. npm test is green; npm run ts-check clean; npm run lint clean; bench/bench-proof-loop.js runs in the same ballpark as the pre-compiler hand-written rules.

ESM-only repackage and test/docs overhaul, the largest release since the extraction of deep6 at 1.1.0.

• CommonJS build removed. yopl ships as pure ESM. CJS consumers can use Node's built-in dynamic import(); a smoke-test demonstrating the interop pattern lives at tests/test-cjs.cjs and runs via node tests/test-cjs.cjs.
• TypeScript typings added. Hand-written .d.ts sidecars for every source module. npm run ts-check runs tsc --noEmit against the typings plus a dedicated TypeScript surface test (tests/test-types.ts).
• Tests restructured. Per-driver test files (test-{solve,gen,async,asyncGen}.js) split out of a monolithic suite, plus dedicated test-system.js and test-rules.js for the predicate libraries. Run with npm test.
• Simplified list creation. Helper exports — head, term, list, listHead, rest — replace the inlined object-literal patterns common in older yopl rule definitions. The wiki's Writing rules page documents the new shapes.
• Bug fixes and perf improvements in the proof loop and the rule libraries.
• Expanded docs. ARCHITECTURE.md, llms.txt, llms-full.txt, AGENTS.md, plus per-module wiki pages (solve, solvers-gen, solvers-async, solvers-asyncGen, rules-system, rules-comp, rules-math, rules-bits, rules-logic).

Cliff-notes preserved verbatim from README.md for releases that predate this long-form page:

• 1.1.4 — updated dependencies.
• 1.1.3 — updated dependencies.
• 1.1.2 — updated dependencies.
• 1.1.1 — updated dependencies.
• 1.1.0 — deep6 was extracted from this package and is now a dependency.
• 1.0.1 — added the exports statement.
• 1.0.0 — first 1.0 release.