Function parseAComponentValue

lib/css/syntax.js:2166–2181

(input, pos, options = {})

 * @returns {ComponentValue | undefined} the parsed component value, or `undefined` on empty / trailing-garbage input
 */
const parseAComponentValue = (input, pos, options = {}) => {
	// 1. Normalize input, and set input to the result.
	const ts = normalizeIntoTokenStream(input, pos, options.comment);
	useObjectBackend(ts.locConverter);
	// 2. Discard whitespace from input.
	while (ts.next().type === TT_WHITESPACE) ts.discard();
	// 3. If input is empty, return a syntax error.
	if (ts.next().type === TT_EOF) return undefined;
	// 4. Consume a component value from input and let value be the return value.
	const result = consumeAComponentValue(ts);
	// 5. Discard whitespace from input.
	while (ts.next().type === TT_WHITESPACE) ts.discard();
	// 6. If input is empty, return value. Otherwise, return a syntax error.
	if (ts.next().type === TT_EOF) return result;
	return undefined;
};

/**
 * Parse a list of component values, CSS Syntax Level 3