splitTopLevelSpaces function

List<String> splitTopLevelSpaces(String input)

Splits input on runs of top-level whitespace.

Whitespace inside brackets or quotes does not split, so inset 0px 0px 0px 2px light-dark(rgba(5, 54, 89, 0.15), #FFF) yields six parts, the last being the whole light-dark(...) expression.

Implementation

List<String> splitTopLevelSpaces(String input) {
  final parts = <String>[];
  final buffer = StringBuffer();
  var depth = 0;
  String? quote;
  var isEscaped = false;

  void flush() {
    if (buffer.isNotEmpty) {
      parts.add(buffer.toString());
      buffer.clear();
    }
  }

  for (var i = 0; i < input.length; i++) {
    final char = input[i];

    if (quote != null) {
      buffer.write(char);
      if (isEscaped) {
        isEscaped = false;
      } else if (char == r'\') {
        isEscaped = true;
      } else if (char == quote) {
        quote = null;
      }
      continue;
    }
    if (char == '"' || char == "'") {
      quote = char;
      buffer.write(char);
      continue;
    }
    if (char == '(') {
      depth++;
    } else if (char == ')') {
      depth = math.max(0, depth - 1);
    } else if (depth == 0 && char.trim().isEmpty) {
      flush();
      continue;
    }
    buffer.write(char);
  }
  flush();

  return parts;
}