dartLine method

String dartLine(String line)

Highlights a line of Dart code.

Implementation

String dartLine(String line) {
  var out = line;

  // Line comments
  final commentIdx = out.indexOf('//');
  String? commentPart;
  if (commentIdx >= 0) {
    commentPart = out.substring(commentIdx);
    out = out.substring(0, commentIdx);
  }

  // Strings
  out = out.replaceAllMapped(
    RegExp(r'"[^"]*"'),
    (m) => '${theme.highlight}${m[0]}${theme.reset}',
  );
  out = out.replaceAllMapped(
    RegExp(r"'[^']*'"),
    (m) => '${theme.highlight}${m[0]}${theme.reset}',
  );

  // Numbers
  out = out.replaceAllMapped(
    RegExp(r'\b\d+(?:\.\d+)?\b'),
    (m) => '${theme.selection}${m[0]}${theme.reset}',
  );

  // Keywords
  const keywords = [
    'class',
    'enum',
    'import',
    'as',
    'show',
    'hide',
    'void',
    'final',
    'const',
    'var',
    'return',
    'if',
    'else',
    'for',
    'while',
    'switch',
    'case',
    'break',
    'continue',
    'try',
    'catch',
    'on',
    'throw',
    'new',
    'this',
    'super',
    'extends',
    'with',
    'implements',
    'static',
    'get',
    'set',
    'async',
    'await',
    'yield',
    'true',
    'false',
    'null'
  ];
  final kwPattern = RegExp(r'\b(' + keywords.join('|') + r')\b');
  out = out.replaceAllMapped(
    kwPattern,
    (m) => '${theme.accent}${theme.bold}${m[0]}${theme.reset}',
  );

  // Punctuation
  out = out.replaceAllMapped(
    RegExp(r'[\[\]\{\}\(\)\,\;\:]'),
    (m) => '${theme.dim}${m[0]}${theme.reset}',
  );

  if (commentPart != null) {
    out = '$out ${theme.gray}$commentPart${theme.reset}';
  }
  return out;
}