splitQuotePrefix function
Splits a line into its quote prefix and the remaining body text.
Returns a record so callers reuse one regex pass; the prefix keeps its trailing space (if present) so re-joining preserves the original spacing.
Example:
splitQuotePrefix('> > hi'); // ('> > ', 'hi')
Audited: 2026-06-12 11:26 EDT
Implementation
(String prefix, String body) splitQuotePrefix(String line) {
final RegExpMatch? match = _kQuotePrefix.firstMatch(line);
if (match == null) return ('', line);
final String prefix = match.group(0)!;
// Strip exactly the matched prefix (anchored at ^) to get the body; using
// replaceFirst avoids a length-based substring() and its RangeError surface.
return (prefix, line.replaceFirst(prefix, ''));
}