# Adversary Review — phase `parse`

## Verdicts

| Gate | Result | Evidence |
|------|--------|----------|
| D1   | PASS   | `parse(tokenize('1+2*3'))` → `BinOp('+', Num(1), BinOp('*', Num(2), Num(3)))` |
| D2   | PASS   | `8-3-2` → `BinOp('-', BinOp('-', Num(8), Num(3)), Num(2))`; `8/4/2` → `BinOp('/', BinOp('/', Num(8), Num(4)), Num(2))` |
| D3   | PASS   | `(1+2)*3` → `BinOp('*', BinOp('+', Num(1), Num(2)), Num(3))` |
| D4   | PASS   | `-5` → `Unary('-', Num(5))`; `-(1+2)` → `Unary('-', BinOp('+', ...))`;  `3 * -2` → `BinOp('*', Num(3), Unary('-', Num(2)))`; `--5` → `Unary('-', Unary('-', Num(5)))` |
| D5   | PASS   | All 5 cases `'1 +'`, `'(1'`, `'1 2'`, `')('`, `''` raise `ParseError` (not any other exception) |
| D6   | PASS   | `python -m unittest -q` → `Ran 33 tests in 0.001s  OK` |

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## Cold-run commands executed

```
python -m unittest -q
python -c "... parse(tokenize('1+2*3'))"      # D1
python -c "... parse(tokenize('4+6/2'))"      # D1
python -c "... parse(tokenize('8-3-2'))"      # D2
python -c "... parse(tokenize('8/4/2'))"      # D2
python -c "... parse(tokenize('(1+2)*3'))"    # D3
python -c "... parse(tokenize('-5'))"         # D4
python -c "... parse(tokenize('-(1+2)'))"     # D4
python -c "... parse(tokenize('3 * -2'))"     # D4
python -c "... parse(tokenize('--5'))"        # D4 extra
python -c "... [all 5 error cases]"           # D5
```

Extra edge cases (adversarial):
- `()` → ParseError ✓
- `1++2` → ParseError ✓ (no unary plus)
- `1 + + 2` → ParseError ✓
- `*3` → ParseError ✓
- `1*(2+3)*4` → `BinOp('*', BinOp('*', Num(1), BinOp('+', Num(2), Num(3))), Num(4))` ✓
- `-1+2` → `BinOp('+', Unary('-', Num(1)), Num(2))` ✓
- `1+2*3+4` → `BinOp('+', BinOp('+', Num(1), BinOp('*', Num(2), Num(3))), Num(4))` ✓

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## Notes

- The `if not tokens: raise ParseError("Empty token list")` guard in `parse()` is **dead code** — `tokenize("")` always appends an EOF token so the list is never empty. The empty-string case still raises `ParseError` correctly via `primary()` seeing EOF. Not a bug; harmless dead code.
- Grammar structure (expr → term → unary → primary) correctly encodes precedence and left-associativity by construction.

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## Summary

review(parse): PASS D1,D2,D3,D4,D5,D6 — cold-verified all gates @2026-06-15T02:00Z