Feature Matrix
| Area | Status | Notes |
|---|---|---|
| LR parsing (shift/reduce/accept) | Implemented | Table-driven, generic over languages |
| Lexer, extras, EOF | Implemented | Longest match, allocation-free lookahead |
Error recovery (ERROR/MISSING) | Implemented | Bounded budgets, error costs |
| Incremental parsing + reuse | Implemented | Sorted interval index, structural equality verified |
| Changed ranges | Implemented | Minimal structural diffs |
| Tree / Node / Cursor | Implemented | Allocation-free reads and moves |
| Queries, captures, quantifiers | Implemented | Greedy repetition, anchors |
Predicates #eq?/#match?/#contains? (+negations) | Implemented | Small built-in regex subset, all/any semantics |
Predicates #any-of?/#not-any-of?/#is?/#is-not? | Implemented | Membership + node-property checks |
Predicates any-eq?/any-match? (+negations) | Implemented | Any-node variants, validated shapes |
Directives #set!/select-adjacent!/strip! | Implemented | Parsed + exposed; native apply helpers |
Negated fields !field, audited anchors | Implemented | First/last named, named-adjacency |
Groups ((...) (#...)) | Implemented | Single pattern + predicates |
| External scanners | Implemented | Per-state dispatch, caching, outline demo |
| Aliases | Implemented | Substitution on reduce; demoed by s-expression grammar |
| Supertypes | Implemented | Subtype expansion in query matching |
| Included ranges | Implemented | Validated; lexer-enforced |
| Callback input + streaming | Implemented | parseWithInput buffers; parseStream lexes incrementally |
| UTF-16 input | Implemented | LE/BE transcode, BOM + surrogate errors |
| Bundled grammars | Implemented | Expression + s-expression + JSON + outline |
| Conformance corpus | Implemented | zig build conformance, embedded in tests |
| Fuzz target | Implemented | zig build fuzz over parser + queries |
| 32/64-bit + ARM64 + WASM | Implemented | 8 OS targets compile; wasm32-wasi validated |
Statuses use exactly these words: Implemented, Partial, Experimental, Not implemented. Deliberate differences from upstream are documented in Upstream Conformance.