# JOURNAL — phase lex

## Implementation notes

- Used `dataclass` for `Token` so equality works naturally in tests.
- `value` field: int for integers, float for floats (including `.5` and `10.`), str for operators, None for EOF.
- Number parsing handles leading-dot (`.5`) and trailing-dot (`10.`) cases via a single scan loop tracking `has_dot`.
- `LexError` extends `Exception` directly; message includes the char repr and position index.
- 15 tests cover all DoD items plus edge cases (tab whitespace, `$`, letter `x`).