formatHeader function

Implementation

String formatHeader(
  int length, {
  String? key,
  List<String>? fields,
  String? delimiter,
  String? lengthMarker,
}) {
  final String actualDelimiter = delimiter ?? comma;
  final String actualLengthMarker = lengthMarker ?? '';

  String header = '';

  if (key != null) {
    header += encodeKey(key);
  }

  // Only include delimiter if it's not the default (comma)
  header +=
      '[$actualLengthMarker$length${actualDelimiter != defaultDelimiters ? actualDelimiter : ''}]';

  if (fields != null) {
    final quotedFields = fields.map(encodeKey);
    header += '{${quotedFields.join(actualDelimiter)}}';
  }

  header += ':';

  return header;
}