Recent Commits to lark:master

Scan: Added small warning (possibly TODO if a need arises)

Add more scan() tests

scan(): search start terminals directly so ignored spans aren't skipped

scan(): carry line/column counts across passes instead of recounting

scan: validate config eagerly, reject custom lexers, tighten errors

- Split ParsingFrontend.scan() into _scan() so configuration errors raise on the call
- Lark.scan() now checks parser='lalr' up front too. Reject custom lexer
- Re-raise ConfigurationError instead of counting it as ValueError
- Check source positions on every replayed token, not just the last
docstring.
- Improves docs
- Adds tests

Export ScanMatch from the top-level lark package

Test that Token end positions survive deepcopy and pickle

Docs: Added recipe for using scan()

Add Lark.scan() for finding grammar matches in text, and parsing them.

It finds and parses each non-overlapping match, yielding the longest possible match.

Reimplementation of the long-standing #1429 PR on top of the merged
TextSlice support, with some modifications.

Token: preserve end_line/end_column/end_pos in __deepcopy__ and __reduce__

Both methods only copied start_pos/line/column, silently dropping the end
positions.