func yaml_parser_scan_tag()

in yaml/scannerc.go [1854:1936]

• 54 lines of code
• 16 McCabe index (conditional complexity)

func yaml_parser_scan_tag(parser *yaml_parser_t, token *yaml_token_t) bool {
	var handle, suffix []byte

	start_mark := parser.mark

	// Check if the tag is in the canonical form.
	if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
		return false
	}

	if parser.buffer[parser.buffer_pos+1] == '<' {
		// Keep the handle as ''

		// Eat '!<'
		skip(parser)
		skip(parser)

		// Consume the tag value.
		if !yaml_parser_scan_tag_uri(parser, false, nil, start_mark, &suffix) {
			return false
		}

		// Check for '>' and eat it.
		if parser.buffer[parser.buffer_pos] != '>' {
			yaml_parser_set_scanner_error(parser, "while scanning a tag",
				start_mark, "did not find the expected '>'")
			return false
		}

		skip(parser)
	} else {
		// The tag has either the '!suffix' or the '!handle!suffix' form.

		// First, try to scan a handle.
		if !yaml_parser_scan_tag_handle(parser, false, start_mark, &handle) {
			return false
		}

		// Check if it is, indeed, handle.
		if handle[0] == '!' && len(handle) > 1 && handle[len(handle)-1] == '!' {
			// Scan the suffix now.
			if !yaml_parser_scan_tag_uri(parser, false, nil, start_mark, &suffix) {
				return false
			}
		} else {
			// It wasn't a handle after all.  Scan the rest of the tag.
			if !yaml_parser_scan_tag_uri(parser, false, handle, start_mark, &suffix) {
				return false
			}

			// Set the handle to '!'.
			handle = []byte{'!'}

			// A special case: the '!' tag.  Set the handle to '' and the
			// suffix to '!'.
			if len(suffix) == 0 {
				handle, suffix = suffix, handle
			}
		}
	}

	// Check the character which ends the tag.
	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
		return false
	}
	if !is_blankz(parser.buffer, parser.buffer_pos) {
		yaml_parser_set_scanner_error(parser, "while scanning a tag",
			start_mark, "did not find expected whitespace or line break")
		return false
	}

	end_mark := parser.mark

	// Create a token.
	*token = yaml_token_t{
		typ:        yaml_TAG_TOKEN,
		start_mark: start_mark,
		end_mark:   end_mark,
		value:      handle,
		suffix:     suffix,
	}
	return true
}