parseOn method

@override Result<String> parseOn(Context context)

Primitive method doing the actual parsing.

The method is overridden in concrete subclasses to implement the parser specific logic. The methods takes a parse context and returns the resulting context, which is either a Success or Failure context.

Implementation

@override
Result<String> parseOn(Context context) {
  final buffer = context.buffer;
  final start = context.position;
  final end = buffer.length;
  var position = start;
  var count = 0;
  while (count < min) {
    if (position >= end || !predicate.test(buffer.codeUnitAt(position))) {
      return context.failure(message, position);
    }
    position++;
    count++;
  }
  while (position < end && count < max) {
    if (!predicate.test(buffer.codeUnitAt(position))) {
      break;
    }
    position++;
    count++;
  }
  return context.success(buffer.substring(start, position), position);
}