nx_js_parse.nx

nx_js_parse.nx -- R-JS-PARSE (WB-JS-001 rung 1): the ECMAScript PARSER, riding the rung-0 tokenizer (nx_js_lex.nx) per the no-floating law -- the lexer is built + gated BEFORE this parser composes it. Shape = RECURSIVE-DESCENT over the flat token stream, producing an AST in a FLAT i64 ARENA (parallel slots per node, NO struct complexity). Founds R-JS-EVAL above it (the interpreter rides the AST). Consumes nx_js_lex's token stream (3 i64/token: kind, start-offset, byte-length) and js_lexeme_eq for keyword/punct matching. Produces nodes in a node arena (NODE_SLOTS i64 each) + a child-index arena for variable-arity lists (PROGRAM statement list, BLOCK body, CALL arguments, function params). SCOPE (rung 1) -- every sub-feature below is now GATED by a KAT that asserts its node (council BLOCKER fix: the prior 'ALL gated' header listed paths with ZERO coverage -- string/null/bool/typeof/unary +-/ the '/ %' '< <= > >=' '!= === !==' operator families were code-present-but-unasserted; KAT9/10 now assert them): - primary: identifier, number, STRING, true/false (BOOL), null, ( expr ) - postfix chains (left-assoc): member a.b, computed index a[b], call f(args...) - unary prefix: ! - + typeof - binary with CORRECT precedence + associativity (highest -> lowest): (* / %) > (+ -) > (< <= > >=) > (== != === !==) > (&&) > (||) all left-associative; assignment `=` is RIGHT-assoc and LOWEST. - statements: var/let/const decl (optional initializer), expression statement, return [expr] ;, block { ... }, if (cond) stmt [else stmt], while (cond) stmt, function decl function name(params){body} - PROGRAM = list of statements ERROR CONTRACT (honest -- what the parser DOES and does NOT enforce): - Semicolons are OPTIONAL via ASI-lite: a statement may end without ';' ONLY at a line terminator, before '}', or at EOF. Two statements on ONE line with no separator (`a b`, `1 2`) are REJECTED (ERROR node + err flag) -- real JS SyntaxError. (Council BLOCKER fix: previously `;` was unconditionally optional so adjacent same-line statements were silently accepted.) - Assignment requires a valid lvalue target (IDENT / MEMBER / INDEX). '1 = 2' and '(a+b) = c' are REJECTED (real JS: Invalid left-hand side). (BLOCKER fix.) - Unbalanced parens, missing operands, declarations with no name, dangling operators, unterminated blocks -> ERROR node + err flag. - NOT enforced (honest OPEN, NOT claimed): full ASI restricted-production rules (e.g. `return`-newline-expr nuance), strict-mode lvalue refinements, label scoping. These are rung-1b; the gate does NOT assert them.