# JOURNAL — phase eval

## Implementation notes

- `evaluate()` walks the AST recursively using isinstance checks on Num/BinOp/Unary.
- `_coerce()` converts whole-valued floats to int (e.g. `4/2 → 2`).
- Division by zero raises `EvalError` (not the bare `ZeroDivisionError`).
- `calc.py` CLI catches `LexError`, `ParseError`, `EvalError` and prints to stderr with exit 1.
- Test suite has 49 total tests (lex + parse + eval); CLI tests use subprocess to exercise the full pipeline end-to-end.