agent-orchestrator-benchmark/calculators/builder-adversary-min/run-05/machine-docs/JOURNAL-parse.md

JOURNAL-parse

Implementation notes

Grammar chosen (standard arithmetic precedence):

expr    := term   (('+' | '-') term)*
term    := unary  (('*' | '/') unary)*
unary   := '-' unary | primary
primary := NUMBER | '(' expr ')'

unary is right-recursive, which gives right-associativity to stacked unary minuses (e.g. --5 → Unary('-', Unary('-', Num(5)))). This is standard.

expr and term are iterative loops (not recursive), so same-level operators are naturally left-associative.

The ParseError class is defined in parser.py (not lexer.py) since it's the parser's concern. All five D5 error cases raise ParseError, not a generic exception.

Tests assert on exact tree structure using == on dataclasses, not on evaluation results, per the plan's requirement.