A simple example of using Dart's "enhanced" enums for ANSI escape sequences

ansi.dart

/// ANSI escape sequence constants.
///
/// See also:
/// - <https://vt100.net/docs/vt100-ug/chapter3.html>.
/// - <https://www.lihaoyi.com/post/BuildyourownCommandLinewithANSIescapecodes.html>
library ansi;

/// Provides constants for 16-bit colors and styles using ANSI-escape sequences.
enum AnsiEscapes16Bit {
  /// Resets all styled output after this escape sequence.
  reset(0),

  bold(1),
  underline(4),

  /// Reverses the set foreground and background colors.
  reversed(7),

  foregroundBlack(30),
  foregroundRed(31),
  foregroundGreen(32),
  foregroundYellow(33),
  foregroundBlue(34),
  foregroundMagenta(35),
  foregroundCyan(36),
  foregroundWhite(37),

  foregroundBrightBlack.bright(30),
  foregroundBrightRed.bright(31),
  foregroundBrightGreen.bright(32),
  foregroundBrightYellow.bright(33),
  foregroundBrightBlue.bright(34),
  foregroundBrightMagenta.bright(35),
  foregroundBrightCyan.bright(36),
  foregroundBrightWhite.bright(37),

  backgroundBlack(40),
  backgroundRed(41),
  backgroundGreen(42),
  backgroundYellow(43),
  backgroundBlue(44),
  backgroundMagenta(45),
  backgroundCyan(46),
  backgroundWhite(47),

  backgroundBrightBlack.bright(40),
  backgroundBrightRed.bright(41),
  backgroundBrightGreen.bright(42),
  backgroundBrightYellow.bright(43),
  backgroundBrightBlue.bright(44),
  backgroundBrightMagenta.bright(45),
  backgroundBrightCyan.bright(46),
  backgroundBrightWhite.bright(47);

  /// Escape sequence to be added as part of the output to apply this style.
  final String value;

  const AnsiEscapes16Bit(int value) : value = '$_ansiPrefix${value}m';
  const AnsiEscapes16Bit.bright(int value) : value = '$_ansiPrefix$value;1m';

  static const _ansiPrefix = '\u001b[';
}