extract static method

({String cleanedSql, List<String> paramNames}) extract(String sql)

Extracts named parameters and returns SQL with positional placeholders.

paramNames preserves placeholder occurrence order, including repeats.

Implementation

static ({String cleanedSql, List<String> paramNames}) extract(String sql) {
  final paramNames = <String>[];
  final cleanedSql = StringBuffer();
  var index = 0;

  while (index < sql.length) {
    final char = sql[index];

    if (char == "'" || char == '"' || char == '[' || char == '`') {
      final end = _consumeQuotedSegment(sql, start: index, delimiter: char);
      cleanedSql.write(sql.substring(index, end));
      index = end;
      continue;
    }

    final dollarQuotedEnd = _consumeDollarQuotedSegment(sql, start: index);
    if (dollarQuotedEnd != null) {
      cleanedSql.write(sql.substring(index, dollarQuotedEnd));
      index = dollarQuotedEnd;
      continue;
    }

    if (char == '-' && _peek(sql, index + 1) == '-') {
      final end = _consumeLineComment(sql, start: index);
      cleanedSql.write(sql.substring(index, end));
      index = end;
      continue;
    }

    if (char == '/' && _peek(sql, index + 1) == '*') {
      final end = _consumeBlockComment(sql, start: index);
      cleanedSql.write(sql.substring(index, end));
      index = end;
      continue;
    }

    final placeholderName = _tryReadPlaceholder(sql, index);
    if (placeholderName != null) {
      paramNames.add(placeholderName.name);
      cleanedSql.write('?');
      index = placeholderName.end;
      continue;
    }

    cleanedSql.write(char);
    index++;
  }

  return (cleanedSql: cleanedSql.toString(), paramNames: paramNames);
}