codeErrorFragment function

String codeErrorFragment(
  1. String input,
  2. int linePos,
  3. int columnPos,
  4. [Settings settings]
)

Implementation

String codeErrorFragment(String input, int linePos, int columnPos,
    [Settings settings]) {
  final splitter = new RegExp(r"\r\n?|\n|\f");
  final lines = input.split(splitter);
  settings = settings != null ? settings : new Settings();
  final startLinePos = max(1, linePos - settings.extraLines) - 1;
  final endLinePos = min(linePos + settings.extraLines, lines.length);
  final maxNumLength = endLinePos.toString().length;
  final prevLines =
      printLines(lines, startLinePos, linePos, maxNumLength, settings);
  final targetLineBeforeCursor = printLine(
      lines[linePos - 1].substring(0, columnPos - 1),
      linePos,
      maxNumLength,
      settings);
  final cursorLine = repeatString(' ', targetLineBeforeCursor.length) + '^';
  final nextLines =
      printLines(lines, linePos, endLinePos, maxNumLength, settings);

  return [prevLines, cursorLine, nextLines]
      .where((c) => c != null && c != 0)
      .join('\n');
}