js/src/SinglyLinkedList.js
function ( iterable = null ) {

	this.front = null ;
	this.back = null ;
	this.length = 0 ;

	if ( iterable !== null ) {

		for ( let value of iterable ) this.push( value ) ;

	}

}
function ( iterable = null ) {

	this.front = null ;
	this.back = null ;
	this.length = 0 ;

	if ( iterable !== null ) {

		for ( let value of iterable ) this.push( value ) ;

	}

}
Doubly linked list implementation
making use of dummy nodes for the
sake of simplicity.