Replace permissive is_symbol_char (negative check — everything not a
delimiter) with spec-compliant is_ident_start/is_ident_char (positive
check matching the exact character sets documented in parser.sx).
Changes:
- ident-start: remove extra chars (|, %, ^, $) not in spec
- ident-char: add comma (,) per spec
- Comma (,) now handled as dedicated unquote case in match, not in
the catch-all fallback — matches spec dispatch order
- Remove ~@ splice-unquote alias (spec only defines ,@)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
giles
0c7567925e