function len(head) {

			var length = 0;

			while (head !== null) {

				++length;
				head = head.next;
			}

			return length;
		}
function len(head) {

			var length = 0;

			while (head !== null) {

				++length;
				head = head.next;
			}

			return length;
		}
function len ( head ) { var length = 0 ; while ( head !== null ) { ++ length ; head = head . next ; } return length ; }
/* js/src/utils/len.js
/ * js / src / utils / len . js