# STATUS — phase lex

## Gates

### D1 — numbers

**What:** Integers and floats tokenize to NUMBER with correct numeric value (int or float).

**Command:**
```bash
python -c "from calc.lexer import tokenize; print([(t.kind,t.value) for t in tokenize('42')])"
python -c "from calc.lexer import tokenize; print([(t.kind,t.value) for t in tokenize('3.14')])"
python -c "from calc.lexer import tokenize; print([(t.kind,t.value) for t in tokenize('.5')])"
python -c "from calc.lexer import tokenize; print([(t.kind,t.value) for t in tokenize('10.')])"
```

**Expected:** NUMBER with int value for integers; float for `3.14`, `.5`, `10.`

**Observed:**
```
[('NUMBER', 42), ('EOF', None)]        # int
[('NUMBER', 3.14), ('EOF', None)]      # float
[('NUMBER', 0.5), ('EOF', None)]       # leading dot
[('NUMBER', 10.0), ('EOF', None)]      # trailing dot
```

**Result: PASS**

---

### D2 — operators & parens

**What:** `+ - * / ( )` each tokenize to their correct kind.

**Command:**
```bash
python -c "from calc.lexer import tokenize; print([t.kind for t in tokenize('1+2*3')])"
```

**Expected:** `['NUMBER', 'PLUS', 'NUMBER', 'STAR', 'NUMBER', 'EOF']`

**Observed:** `['NUMBER', 'PLUS', 'NUMBER', 'STAR', 'NUMBER', 'EOF']`

**Result: PASS**

---

### D3 — whitespace & errors

**What:** Spaces/tabs skipped; invalid chars raise LexError with char and position.

**Command:**
```bash
python -c "from calc.lexer import tokenize; print([t.kind for t in tokenize('  12  +  3 ')])"
python -c "from calc.lexer import tokenize; tokenize('1 @ 2')"
```

**Expected:** Whitespace version → `['NUMBER', 'PLUS', 'NUMBER', 'EOF']`; `@` raises `LexError` with `@` and position `2` in message.

**Observed:**
- Whitespace: `['NUMBER', 'PLUS', 'NUMBER', 'EOF']`
- LexError: `calc.lexer.LexError: unexpected character '@' at position 2`

**Result: PASS**

---

### D4 — tests green

**What:** `calc/test_lexer.py` passes `python -m unittest`, 0 failures, covering D1–D3.

**Command:**
```bash
python -m unittest -q
```

**Expected:** `Ran N tests in ... OK`

**Observed:**
```
----------------------------------------------------------------------
Ran 18 tests in 0.000s

OK
```

**Result: PASS**

---

### Exact plan verification commands

```bash
python -m unittest -q
# → Ran 18 tests in 0.000s  OK

python -c "from calc.lexer import tokenize; print([(t.kind,t.value) for t in tokenize('3.5*(1-2)')])"
# → [('NUMBER', 3.5), ('STAR', '*'), ('LPAREN', '('), ('NUMBER', 1), ('MINUS', '-'), ('NUMBER', 2), ('RPAREN', ')'), ('EOF', None)]

python -c "from calc.lexer import tokenize; tokenize('1 @ 2')"
# → calc.lexer.LexError: unexpected character '@' at position 2
```

## DONE