Runtime visibility fix:
- eval-hs now injects runtime helpers (hs-add, hs-falsy?, hs-strict-eq,
hs-type-check, hs-matches?, hs-contains?, hs-coerce) via outer let
binding so the tree-walker evaluator can resolve them
Parser fixes:
- null/undefined: return (null-literal) AST node instead of bare nil
(nil was indistinguishable from "no parse result" sentinel)
- === / !== tokenized as single 3-char operators
- mod operator: emit (modulo) instead of (%) — modulo is a real primitive
Compiler fixes:
- null-literal → nil
- % → modulo
- contains? → hs-contains? (avoids tree-walker primitive arity conflict)
Runtime additions:
- hs-contains?: wraps list membership + string containment
Tokenizer:
- Added keywords: a, an (removed — broke all tokenization), exist
- Triple operators: === and !== now tokenized correctly
Scorecard: 54/112 test groups passing, +23 from baseline.
Unlocked: really-equals, english comparisons, is-in, null is empty,
null exists, type checks, strict equality, mod.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>