# REVIEW — phase lex (Adversary)

_Last updated: 2026-06-15T05:08:00Z_

## Status
All 4 gates PASSED. Phase is DONE pending Builder writing "## DONE" to STATUS.

## Gates

| Gate | Status | Timestamp | Notes |
|------|--------|-----------|-------|
| D1   | PASS   | 2026-06-15T05:06:00Z | All number forms correct |
| D2   | PASS   | 2026-06-15T05:07:00Z | All operators/parens correct |
| D3   | PASS   | 2026-06-15T05:07:30Z | Whitespace skipped, LexError raised with char+position |
| D4   | PASS   | 2026-06-15T05:08:00Z | 23 tests, 0 failures; all plan cold-verify commands pass |

---

## Detailed verdicts

### lex/D1: PASS @2026-06-15T05:06:00Z

Cold-start verification from own clone. All Builder-provided checks pass:
- `tokenize('42')` → `[NUMBER(42), EOF]`, value is `int` ✓
- `tokenize('3.14')` → `NUMBER(3.14)` float ✓
- `tokenize('.5')` → `NUMBER(0.5)` float ✓
- `tokenize('10.')` → `NUMBER(10.0)` float ✓
- list-equality with `Token('NUMBER',42)` and `Token('EOF',None)` ✓

Independent break-it probes:
- `tokenize('')` → `[EOF]` ✓
- `tokenize('0')` → `NUMBER(0)` int ✓
- `tokenize('999999999999')` → large int ✓
- NOTED (not D1 scope): `tokenize('.')` raises `ValueError` not `LexError` — filed as finding F1

### lex/D2: PASS @2026-06-15T05:07:00Z

Cold-start verification. All Builder-provided checks pass:
- `tokenize('1+2*3')` → kinds `['NUMBER','PLUS','NUMBER','STAR','NUMBER','EOF']` ✓
- All 6 single-char operators tokenize to correct kinds ✓

Independent break-it probes:
- Tab whitespace skipped ✓
- Operator value is the character itself (e.g. `'+'`) — acceptable per design ✓
- Nested parens `((1))` tokenize correctly ✓

### lex/D3: PASS @2026-06-15T05:07:30Z

Cold-start verification. All Builder-provided checks pass:
- `tokenize('  12  +  3 ')` → `['NUMBER','PLUS','NUMBER','EOF']`, values 12 and 3 ✓
- `tokenize('1 @ 2')` raises `LexError` with `@` and position `2` in message ✓
- `tokenize('abc')` raises `LexError` ✓

Independent break-it probes:
- Tab whitespace skipped ✓
- `tokenize('$')` raises `LexError` at position 0 ✓
- NOTED: `tokenize('.')` raises bare `ValueError` not `LexError` — same as F1 below
- NOTED: `tokenize('1.2.3')` raises bare `ValueError` not `LexError` — F1 covers this

DoD for D3 specifies `@`, `$`, letters as examples of invalid chars. The standalone-dot
edge case is not in the explicit DoD and the plan's mandated test suite does not include it.
PASS granted; finding F1 is advisory for the Builder's consideration.

### lex/D4: PASS @2026-06-15T05:08:00Z

Cold-start verification. Plan's exact commands run:
- `python -m unittest -q` → `Ran 23 tests in 0.000s  OK` ✓
- `tokenize('3.5*(1-2)')` → `[('NUMBER',3.5),('STAR','*'),('LPAREN','('),('NUMBER',1),('MINUS','-'),('NUMBER',2),('RPAREN',')'),('EOF',None)]` ✓
- `tokenize('1 @ 2')` → raises `calc.lexer.LexError: unexpected character '@' at position 2` ✓

Mandated test cases present in `calc/test_lexer.py`:
- `"  12  +  3 "` ✓ (line 79, 84)
- `"3.5*(1-2)"` ✓ (line 71, 118)
- `"1 @ 2"` raises LexError ✓ (lines 93, 105, 112)

---

## Adversary findings

### F1 (advisory) — malformed float literals raise ValueError not LexError

**Severity:** Low — not in explicit DoD, no test covers it.

**Repro:**
```python
from calc.lexer import tokenize
tokenize('.')      # raises ValueError, not LexError
tokenize('1.2.3') # raises ValueError, not LexError
```

**Expected:** `LexError` (consistent with the module's error contract).

**Actual:** `ValueError: could not convert string to float: '.'`

**Recommendation:** Wrap the `float()` call in a try/except and re-raise as `LexError`.
This is advisory — does not block DONE since it falls outside D1–D3's explicit DoD requirements.