parseOn method

@override Result<R> 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<R> parseOn(Context context) {
  final beforeParser = before;
  if (beforeParser != null) {
    final beforeContext = beforeParser.parseOn(context);
    if (beforeContext.isFailure) {
      return beforeContext.failure(beforeContext.message);
    }
    context = beforeContext;
  }
  final resultContext = delegate.parseOn(context);
  if (resultContext.isFailure) {
    return resultContext;
  }
  context = resultContext;
  final afterParser = after;
  if (afterParser != null) {
    final afterContext = afterParser.parseOn(context);
    if (afterContext.isFailure) {
      return afterContext.failure(afterContext.message);
    }
    context = afterContext;
  }
  return context.success(resultContext.value);
}