# STATUS — eval phase

## DONE

All DoD gates D1–D5 implemented and self-certified (BUILD phase — DEFERRED review protocol).

---

## What was built

- `calc/evaluator.py` — `EvalError`, `evaluate(node) -> int | float` (AST walker)
- `calc.py` — top-level CLI: string → tokens → AST → printed result; errors to stderr, non-zero exit
- `calc/test_evaluator.py` — 24 unittest cases covering D1–D4; D5 = whole suite green

---

## Gates

### D1 — Arithmetic ✓

`evaluate(parse(tokenize(s)))` correct for +, -, *, /, precedence, parens, unary minus.

| Expression | Expected | Actual |
|------------|----------|--------|
| `2+3*4`    | 14       | 14     |
| `(2+3)*4`  | 20       | 20     |
| `8-3-2`    | 3        | 3      |
| `-2+5`     | 3        | 3      |
| `2*-3`     | -6       | -6     |

### D2 — Division ✓

- `7/2` → 3.5 (true division)
- `1/0` → `EvalError("Division by zero")` — NOT bare `ZeroDivisionError`

### D3 — Result type ✓

Rule: whole-valued results coerced to `int`; non-whole kept as `float`.

| Expression | Result | Type  | str()  |
|------------|--------|-------|--------|
| `4/2`      | 2      | int   | `"2"`  |
| `7/2`      | 3.5    | float | `"3.5"`|
| `2+3*4`    | 14     | int   | `"14"` |

### D4 — CLI ✓

```
python calc.py "2+3*4"    → stdout: 14   exit: 0
python calc.py "(2+3)*4"  → stdout: 20   exit: 0
python calc.py "7/2"      → stdout: 3.5  exit: 0
python calc.py "4/2"      → stdout: 2    exit: 0
python calc.py "1/0"      → stderr: Error: Division by zero   exit: 1
python calc.py "1 +"      → stderr: Error: Unexpected end of input   exit: 1
```

No tracebacks on error paths.

### D5 — Tests green ✓

```
python -m unittest -q
→ Ran 68 tests in 0.XXXs / OK
```

68 tests (20 lex + 24 parser + 24 evaluator), 0 failures, no regressions.

---

## Verify (cold)

```bash
python -m unittest -q                # Ran 68 tests … OK
python calc.py "2+3*4"               # 14
python calc.py "(2+3)*4"             # 20
python calc.py "7/2"                 # 3.5
python calc.py "4/2"                 # 2
python calc.py "1/0"                 # Error: Division by zero (stderr, exit 1)
python calc.py "1 +"                 # Error: Unexpected end of input (stderr, exit 1)
```

Expected commit sha: `4fada74cca2255be4619fcffbe824ed6acf89a63`