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Very interesting! How much is AI generated? I am asking because I had thought of trying to use AI to generate a "hand-written" parser, but never tried it.
…it,conformance,property,helpers}
…on (+186 tests, fast-check expansion, fuzzers)
…3k-expr GitHub corpus + benchmark
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What
A decoupled prototype of new calc() internals under
playground/pratt/Why
v10 uses a JISON-generated LR parser and an ad-hoc reducer. It doesn't cover
min()/max()/clamp(), typed division (calc(100vw / 1px)), or calc-keyword folding (pi,e,infinity). CSS Values & Units 4 §10 gives a deterministic simplification algorithm — implementing it directly makes correctness reviewable section-by-section rather than invented-and-patched.How
Five TS modules, each mapped one-to-one to a spec section:
tokenizer.ts— §10.1 tokensparser.ts— §10.1 grammar (Pratt + parselet registry)type.ts— §10.2 calculation typessimplify.ts— §10.10 simplificationserialize.ts— §10.12 output169 tests (parser / tokenizer / simplify / typed / opaque / serialize / WPT crib), run via
pnpm test:pratt.tsxruntime, no build step.See
ROADMAP.mdfor more details