STATUS-parse

Phase: parse Builder: CLAIMING D1–D6

Claims

Gate	DoD item	Status
D1	Correct precedence: `*`/`/` bind tighter than `+`/`-`	CLAIMED
D2	Left associativity for same-precedence operators	CLAIMED
D3	Parentheses override precedence	CLAIMED
D4	Unary minus (leading, nested, after operator)	CLAIMED
D5	Malformed input raises `ParseError`	CLAIMED
D6	`calc/test_parser.py` passes: 34 tests, 0 failures	CLAIMED

Implementation

calc/parser.py — recursive-descent parser exposing parse(tokens) -> Node
calc/test_parser.py — unittest suite covering D1–D5 (34 tests)

AST node shapes

Num(value)              # value: int | float
BinOp(op, left, right)  # op: '+' | '-' | '*' | '/'
Unary(op, operand)      # op: '-'

Verify (cold)

python -m unittest -q
# Expected: Ran 34 tests in 0.00xs  OK

D1 — precedence assertion

python -c "from calc.lexer import tokenize; from calc.parser import parse; print(parse(tokenize('1+2*3')))"
# Expected: BinOp('+', Num(1), BinOp('*', Num(2), Num(3)))

The * is in the subtree (right of +), proving * binds tighter.

D2 — left associativity assertions

python -c "from calc.lexer import tokenize; from calc.parser import parse; print(parse(tokenize('8-3-2')))"
# Expected: BinOp('-', BinOp('-', Num(8), Num(3)), Num(2))

python -c "from calc.lexer import tokenize; from calc.parser import parse; print(parse(tokenize('8/4/2')))"
# Expected: BinOp('/', BinOp('/', Num(8), Num(4)), Num(2))

D3 — parentheses assertion

python -c "from calc.lexer import tokenize; from calc.parser import parse; print(parse(tokenize('(1+2)*3')))"
# Expected: BinOp('*', BinOp('+', Num(1), Num(2)), Num(3))

D4 — unary minus assertions

python -c "from calc.lexer import tokenize; from calc.parser import parse; print(parse(tokenize('-5')))"
# Expected: Unary('-', Num(5))

python -c "from calc.lexer import tokenize; from calc.parser import parse; print(parse(tokenize('-(1+2)')))"
# Expected: Unary('-', BinOp('+', Num(1), Num(2)))

python -c "from calc.lexer import tokenize; from calc.parser import parse; print(parse(tokenize('3 * -2')))"
# Expected: BinOp('*', Num(3), Unary('-', Num(2)))

D5 — error assertions

python -c "from calc.lexer import tokenize; from calc.parser import parse; parse(tokenize('1 +'))" 2>&1 | grep ParseError
# Expected: line containing "calc.parser.ParseError"

python -c "from calc.lexer import tokenize; from calc.parser import parse; parse(tokenize('(1'))" 2>&1 | grep ParseError

python -c "from calc.lexer import tokenize; from calc.parser import parse; parse(tokenize('1 2'))" 2>&1 | grep ParseError

python -c "from calc.lexer import tokenize; from calc.parser import parse; parse(tokenize(')('))" 2>&1 | grep ParseError

python -c "from calc.lexer import tokenize; from calc.parser import parse; parse(tokenize(''))" 2>&1 | grep ParseError

All five raise calc.parser.ParseError.

Commit

Implemented at HEAD (see git log --oneline -1 after push).

DONE

All D1–D6 gates verified PASS by Adversary at 2026-06-15T03:28Z (commit d97df78). Phase complete.

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