Event _parseNode()

in lib/src/parser.dart [262:354]
77 lines of code
22 McCabe index (conditional complexity)

  Event _parseNode({bool block = false, bool indentlessSequence = false}) {
    var token = _scanner.peek()!;

    if (token is AliasToken) {
      _scanner.scan();
      _state = _states.removeLast();
      return AliasEvent(token.span, token.name);
    }

    String? anchor;
    TagToken? tagToken;
    var span = token.span.start.pointSpan();
    Token parseAnchor(AnchorToken token) {
      anchor = token.name;
      span = span.expand(token.span);
      return _scanner.advance()!;
    }

    Token parseTag(TagToken token) {
      tagToken = token;
      span = span.expand(token.span);
      return _scanner.advance()!;
    }

    if (token is AnchorToken) {
      token = parseAnchor(token);
      if (token is TagToken) token = parseTag(token);
    } else if (token is TagToken) {
      token = parseTag(token);
      if (token is AnchorToken) token = parseAnchor(token);
    }

    String? tag;
    if (tagToken != null) {
      if (tagToken!.handle == null) {
        tag = tagToken!.suffix;
      } else {
        var tagDirective = _tagDirectives[tagToken!.handle];
        if (tagDirective == null) {
          throw YamlException('Undefined tag handle.', tagToken!.span);
        }

        tag = tagDirective.prefix + (tagToken?.suffix ?? '');
      }
    }

    if (indentlessSequence && token.type == TokenType.blockEntry) {
      _state = _State.INDENTLESS_SEQUENCE_ENTRY;
      return SequenceStartEvent(span.expand(token.span), CollectionStyle.BLOCK,
          anchor: anchor, tag: tag);
    }

    if (token is ScalarToken) {
      // All non-plain scalars have the "!" tag by default.
      if (tag == null && token.style != ScalarStyle.PLAIN) tag = '!';

      _state = _states.removeLast();
      _scanner.scan();
      return ScalarEvent(span.expand(token.span), token.value, token.style,
          anchor: anchor, tag: tag);
    }

    if (token.type == TokenType.flowSequenceStart) {
      _state = _State.FLOW_SEQUENCE_FIRST_ENTRY;
      return SequenceStartEvent(span.expand(token.span), CollectionStyle.FLOW,
          anchor: anchor, tag: tag);
    }

    if (token.type == TokenType.flowMappingStart) {
      _state = _State.FLOW_MAPPING_FIRST_KEY;
      return MappingStartEvent(span.expand(token.span), CollectionStyle.FLOW,
          anchor: anchor, tag: tag);
    }

    if (block && token.type == TokenType.blockSequenceStart) {
      _state = _State.BLOCK_SEQUENCE_FIRST_ENTRY;
      return SequenceStartEvent(span.expand(token.span), CollectionStyle.BLOCK,
          anchor: anchor, tag: tag);
    }

    if (block && token.type == TokenType.blockMappingStart) {
      _state = _State.BLOCK_MAPPING_FIRST_KEY;
      return MappingStartEvent(span.expand(token.span), CollectionStyle.BLOCK,
          anchor: anchor, tag: tag);
    }

    if (anchor != null || tag != null) {
      _state = _states.removeLast();
      return ScalarEvent(span, '', ScalarStyle.PLAIN, anchor: anchor, tag: tag);
    }

    throw YamlException('Expected node content.', span);
  }