func yaml_parser_fetch_next_token()

in yaml/scannerc.go [690:863]

• 100 lines of code
• 70 McCabe index (conditional complexity)

func yaml_parser_fetch_next_token(parser *yaml_parser_t) bool {
	// Ensure that the buffer is initialized.
	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
		return false
	}

	// Check if we just started scanning.  Fetch STREAM-START then.
	if !parser.stream_start_produced {
		return yaml_parser_fetch_stream_start(parser)
	}

	// Eat whitespaces and comments until we reach the next token.
	if !yaml_parser_scan_to_next_token(parser) {
		return false
	}

	// Remove obsolete potential simple keys.
	if !yaml_parser_stale_simple_keys(parser) {
		return false
	}

	// Check the indentation level against the current column.
	if !yaml_parser_unroll_indent(parser, parser.mark.column) {
		return false
	}

	// Ensure that the buffer contains at least 4 characters.  4 is the length
	// of the longest indicators ('--- ' and '... ').
	if parser.unread < 4 && !yaml_parser_update_buffer(parser, 4) {
		return false
	}

	// Is it the end of the stream?
	if is_z(parser.buffer, parser.buffer_pos) {
		return yaml_parser_fetch_stream_end(parser)
	}

	// Is it a directive?
	if parser.mark.column == 0 && parser.buffer[parser.buffer_pos] == '%' {
		return yaml_parser_fetch_directive(parser)
	}

	buf := parser.buffer
	pos := parser.buffer_pos

	// Is it the document start indicator?
	if parser.mark.column == 0 && buf[pos] == '-' && buf[pos+1] == '-' && buf[pos+2] == '-' && is_blankz(buf, pos+3) {
		return yaml_parser_fetch_document_indicator(parser, yaml_DOCUMENT_START_TOKEN)
	}

	// Is it the document end indicator?
	if parser.mark.column == 0 && buf[pos] == '.' && buf[pos+1] == '.' && buf[pos+2] == '.' && is_blankz(buf, pos+3) {
		return yaml_parser_fetch_document_indicator(parser, yaml_DOCUMENT_END_TOKEN)
	}

	// Is it the flow sequence start indicator?
	if buf[pos] == '[' {
		return yaml_parser_fetch_flow_collection_start(parser, yaml_FLOW_SEQUENCE_START_TOKEN)
	}

	// Is it the flow mapping start indicator?
	if parser.buffer[parser.buffer_pos] == '{' {
		return yaml_parser_fetch_flow_collection_start(parser, yaml_FLOW_MAPPING_START_TOKEN)
	}

	// Is it the flow sequence end indicator?
	if parser.buffer[parser.buffer_pos] == ']' {
		return yaml_parser_fetch_flow_collection_end(parser,
			yaml_FLOW_SEQUENCE_END_TOKEN)
	}

	// Is it the flow mapping end indicator?
	if parser.buffer[parser.buffer_pos] == '}' {
		return yaml_parser_fetch_flow_collection_end(parser,
			yaml_FLOW_MAPPING_END_TOKEN)
	}

	// Is it the flow entry indicator?
	if parser.buffer[parser.buffer_pos] == ',' {
		return yaml_parser_fetch_flow_entry(parser)
	}

	// Is it the block entry indicator?
	if parser.buffer[parser.buffer_pos] == '-' && is_blankz(parser.buffer, parser.buffer_pos+1) {
		return yaml_parser_fetch_block_entry(parser)
	}

	// Is it the key indicator?
	if parser.buffer[parser.buffer_pos] == '?' && (parser.flow_level > 0 || is_blankz(parser.buffer, parser.buffer_pos+1)) {
		return yaml_parser_fetch_key(parser)
	}

	// Is it the value indicator?
	if parser.buffer[parser.buffer_pos] == ':' && (parser.flow_level > 0 || is_blankz(parser.buffer, parser.buffer_pos+1)) {
		return yaml_parser_fetch_value(parser)
	}

	// Is it an alias?
	if parser.buffer[parser.buffer_pos] == '*' {
		return yaml_parser_fetch_anchor(parser, yaml_ALIAS_TOKEN)
	}

	// Is it an anchor?
	if parser.buffer[parser.buffer_pos] == '&' {
		return yaml_parser_fetch_anchor(parser, yaml_ANCHOR_TOKEN)
	}

	// Is it a tag?
	if parser.buffer[parser.buffer_pos] == '!' {
		return yaml_parser_fetch_tag(parser)
	}

	// Is it a literal scalar?
	if parser.buffer[parser.buffer_pos] == '|' && parser.flow_level == 0 {
		return yaml_parser_fetch_block_scalar(parser, true)
	}

	// Is it a folded scalar?
	if parser.buffer[parser.buffer_pos] == '>' && parser.flow_level == 0 {
		return yaml_parser_fetch_block_scalar(parser, false)
	}

	// Is it a single-quoted scalar?
	if parser.buffer[parser.buffer_pos] == '\'' {
		return yaml_parser_fetch_flow_scalar(parser, true)
	}

	// Is it a double-quoted scalar?
	if parser.buffer[parser.buffer_pos] == '"' {
		return yaml_parser_fetch_flow_scalar(parser, false)
	}

	// Is it a plain scalar?
	//
	// A plain scalar may start with any non-blank characters except
	//
	//      '-', '?', ':', ',', '[', ']', '{', '}',
	//      '#', '&', '*', '!', '|', '>', '\'', '\"',
	//      '%', '@', '`'.
	//
	// In the block context (and, for the '-' indicator, in the flow context
	// too), it may also start with the characters
	//
	//      '-', '?', ':'
	//
	// if it is followed by a non-space character.
	//
	// The last rule is more restrictive than the specification requires.
	// [Go] Make this logic more reasonable.
	//switch parser.buffer[parser.buffer_pos] {
	//case '-', '?', ':', ',', '?', '-', ',', ':', ']', '[', '}', '{', '&', '#', '!', '*', '>', '|', '"', '\'', '@', '%', '-', '`':
	//}
	if !(is_blankz(parser.buffer, parser.buffer_pos) || parser.buffer[parser.buffer_pos] == '-' ||
		parser.buffer[parser.buffer_pos] == '?' || parser.buffer[parser.buffer_pos] == ':' ||
		parser.buffer[parser.buffer_pos] == ',' || parser.buffer[parser.buffer_pos] == '[' ||
		parser.buffer[parser.buffer_pos] == ']' || parser.buffer[parser.buffer_pos] == '{' ||
		parser.buffer[parser.buffer_pos] == '}' || parser.buffer[parser.buffer_pos] == '#' ||
		parser.buffer[parser.buffer_pos] == '&' || parser.buffer[parser.buffer_pos] == '*' ||
		parser.buffer[parser.buffer_pos] == '!' || parser.buffer[parser.buffer_pos] == '|' ||
		parser.buffer[parser.buffer_pos] == '>' || parser.buffer[parser.buffer_pos] == '\'' ||
		parser.buffer[parser.buffer_pos] == '"' || parser.buffer[parser.buffer_pos] == '%' ||
		parser.buffer[parser.buffer_pos] == '@' || parser.buffer[parser.buffer_pos] == '`') ||
		(parser.buffer[parser.buffer_pos] == '-' && !is_blank(parser.buffer, parser.buffer_pos+1)) ||
		(parser.flow_level == 0 &&
			(parser.buffer[parser.buffer_pos] == '?' || parser.buffer[parser.buffer_pos] == ':') &&
			!is_blankz(parser.buffer, parser.buffer_pos+1)) {
		return yaml_parser_fetch_plain_scalar(parser)
	}

	// If we don't determine the token type so far, it is an error.
	return yaml_parser_set_scanner_error(parser,
		"while scanning for the next token", parser.mark,
		"found character that cannot start any token")
}