# STATUS — parse phase (Builder)

## DONE

All DoD items self-certified (BUILD phase — deferred Adversary review).

## DoD Checklist

- **D1 — precedence:** PASS. `*`/`/` bind tighter than `+`/`-`. `1+2*3` → `BinOp('+', Num(1), BinOp('*', Num(2), Num(3)))`.
- **D2 — left associativity:** PASS. `8-3-2` → `BinOp('-', BinOp('-', Num(8), Num(3)), Num(2))`; `8/4/2` → `BinOp('/', BinOp('/', Num(8), Num(4)), Num(2))`.
- **D3 — parentheses:** PASS. `(1+2)*3` → `BinOp('*', BinOp('+', Num(1), Num(2)), Num(3))`.
- **D4 — unary minus:** PASS. `-5` → `Unary('-', Num(5))`; `3 * -2` → `BinOp('*', Num(3), Unary('-', Num(2)))`.
- **D5 — errors:** PASS. All five specified inputs (`"1 +"`, `"(1"`, `"1 2"`, `")("`, `""`) raise `ParseError`.
- **D6 — tests green:** PASS. 35 tests total (11 lexer + 24 parser), 0 failures.

## Verification Commands (for Adversary cold-verify)

```bash
# From repo root
python -m unittest -q
# Expected: Ran 35 tests in X.XXXs / OK (exit 0)

# D1 — precedence
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)))

# D2 — left associativity
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
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
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('3 * -2')))"
# Expected: BinOp('*', Num(3), Unary('-', Num(2)))

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

# D5 — errors (each must raise ParseError, not crash with different exception)
python -c "from calc.lexer import tokenize; from calc.parser import parse, ParseError
try:
    parse(tokenize('1 +'))
    print('FAIL: no error')
except ParseError as e:
    print('OK:', e)"

python -c "from calc.lexer import tokenize; from calc.parser import parse, ParseError
try:
    parse(tokenize('(1'))
    print('FAIL: no error')
except ParseError as e:
    print('OK:', e)"

python -c "from calc.lexer import tokenize; from calc.parser import parse, ParseError
try:
    parse(tokenize('1 2'))
    print('FAIL: no error')
except ParseError as e:
    print('OK:', e)"

python -c "from calc.lexer import tokenize; from calc.parser import parse, ParseError
try:
    parse(tokenize(')('))
    print('FAIL: no error')
except ParseError as e:
    print('OK:', e)"

python -c "from calc.lexer import tokenize; from calc.parser import parse, ParseError
try:
    parse(tokenize(''))
    print('FAIL: no error')
except ParseError as e:
    print('OK:', e)"
```

## AST Shape Reference

Nodes (all `dataclass`es in `calc/parser.py`):

| Class | Fields | Example |
|-------|--------|---------|
| `Num` | `value: int \| float` | `Num(42)`, `Num(3.5)` |
| `BinOp` | `op: str, left: Node, right: Node` | `BinOp('+', Num(1), Num(2))` |
| `Unary` | `op: str, operand: Node` | `Unary('-', Num(5))` |

`ParseError` inherits from `Exception`.

## Files Produced

- `calc/parser.py` — `ParseError`, `Num`, `BinOp`, `Unary`, `Node`, `parse()`
- `calc/test_parser.py` — 24 unittest cases covering D1–D5