# REVIEW — phase `lex`

Adversary cold-verification log. Updated each time a DoD gate is checked.

## Gates

| Gate | Status | Timestamp |
|------|--------|-----------|
| D1 — numbers | PASS | 2026-06-15T02:05Z |
| D2 — operators & parens | PASS | 2026-06-15T02:05Z |
| D3 — whitespace & errors | PASS | 2026-06-15T02:05Z |
| D4 — tests green | PASS | 2026-06-15T02:05Z |

---

## Verdicts

### review(D4): PASS @2026-06-15T02:05Z

```
python -m unittest -q
→ Ran 12 tests in 0.000s  OK
```

12 tests, 0 failures. Covers D1–D3 including required cases.

### review(D1): PASS @2026-06-15T02:05Z

```
tokenize("42")      → [('NUMBER', 42), ('EOF', None)]           ✓
tokenize(".5")      → [('NUMBER', 0.5), ('EOF', None)]          ✓
tokenize("10.")     → [('NUMBER', 10.0), ('EOF', None)]         ✓
tokenize("3.14")    → NUMBER(3.14) verified via test suite      ✓
```

Integer values are `int`, float values are `float`. EOF is present.

### review(D2): PASS @2026-06-15T02:05Z

```
tokenize("1+2*3") kinds → ['NUMBER', 'PLUS', 'NUMBER', 'STAR', 'NUMBER', 'EOF']  ✓
All six operators/parens + - * / ( ) each map to the correct kind.
```

### review(D3): PASS @2026-06-15T02:05Z

```
tokenize("  12  +  3 ") → [('NUMBER', 12), ('PLUS', '+'), ('NUMBER', 3), ('EOF', None)]  ✓
tokenize("1 @ 2")       → LexError: Invalid character '@' at position 2                  ✓
tokenize("abc")         → LexError: Invalid character 'a' at position 0                  ✓
tokenize("$")           → LexError: Invalid character '$' at position 0                  ✓
```

Tabs also skipped (verified in test suite). Error messages include the offending char and position.

---

## Adversarial edge cases tried (all behaved correctly)

- Empty string `""` → `[EOF]` (no crash)
- Whitespace-only `"\t  \t"` → `[EOF]`
- Leading-dot `.5` → `NUMBER(0.5)`
- Trailing-dot `10.` → `NUMBER(10.0)`
- Bare dot `.` → raises `LexError` (not a valid number)
- Letter `abc` → raises `LexError` at position 0
- Dollar `$` → raises `LexError` at position 0

No issues found. All four DoD gates independently verified at commit `a1c68aa`.