ata-validator

Added

• A schema-directed scanner: isValidJSON() answers the verdict from the JSON text without building the document. Parsing is about three quarters of the cost of a request that only needs yes or no, and a rejection now stops at the byte that caused it. The scanner compiles per schema, on the codegen path only, after 64 calls (generating one costs about 20 µs, so a caller that checks one document never pays), and it declines anything outside its supported core: type, properties, required, additionalProperties, items, prefixItems, the length, size and range keywords, pattern, format, const, enum, local $ref (inlined, acyclic, no base-changing keywords below the root), allOf (merged, with the additionalProperties cross-branch rule written out in full), and unevaluated* where it is provably a synonym for additionalProperties/items. Whatever it cannot answer it declines at compile time or bails from at runtime, and the parse path takes over unchanged. tests/test_scanner_differential.js holds the scanner and validate() to the same verdict on the same text: 413,130 comparisons over the official suite, a malformed-JSON corpus and generated corruptions, zero disagreements, and the count must stay at zero.

  • Cross-process medians against the same call forced through JSON.parse: accepted documents 1.19x to 1.43x by size; rejection at the first element 37x at 4 KB and 385x at 41 KB.

  • Generated config schemas are first-class: up to 4096 properties per node, and past 48 names the dispatch is a rolling hash accumulated during the key scan, one lookup in a Map passed outside the source, one startsWith to confirm, bodies shared per distinct subschema, and an in-order fast path for machine-written JSON that resynchronises across omitted optional keys. A 26.6 KB config with 1300 declared properties: 136.7 µs by parse-and-validate, 43.8 µs by scan.

  • isValidJSON also remembers the last (text, verdict) pair, since the verdict is a pure function of the text: a drift monitor re-reading an unchanged file answers in 0.44 µs by native string compare. Withheld when user formats or custom keywords are present, since user functions may not be pure.

Fixed

• An AOT module that cannot carry error detail says so. toStandaloneModule with error detail requested builds the error function from the error generator, which declines some schemas, unevaluated* among them; the runtime validator falls back to the interpreted engine there, but a standalone module has nothing to fall back to, so it shipped with an exact verdict and a single ATA9000 stub for every failure, silently. The module still ships, since the verdict is exact and validating the rare failing document with the runtime Validator is a legitimate pattern, but the degradation is loud in every layer: onWarning on the emitter, a NOTE in the module header, a warnings list in the build() report, a printed warning from ata compile, and a refused build under --strict. Found by a gateway team that lost their per-field startup errors to it.