Linked List Iterator (foreach)

[Mason Green]

Hello, D world.

I've finally gotten around to experimenting with Templates, and was wondering if anyone knows of a simple way to implement a linked list iterator.... Ideally I would like iterate through the list using foreach...

Here's what I have so far.... Any help would be appreciated....

class FastCell(T)  {
	T elt;
	FastCell!(T) next;
	
    this(T elt, FastCell!(T) next) { 
        this.elt = elt; 
        this.next = next; 
    }
}

/**
	A linked-list of elements. 
**/
class FastList(T)  {

    alias FastCell!(T) Fast;
    
	Fast head;

	/**
		Creates a new empty list.
	**/
	this() {
        head = null;
	}

	/**
		Add an element at the head of the list.
	**/
	void add(T item) {
		head = new Fast(item, head);
	}

	/**
		Returns the first element of the list, or null
		if the list is empty.
	**/
	T first() {
		return (head is null ? null : head.elt);
	}

	/**
		Removes the first element of the list and
		returns it or simply returns null if the
		list is empty.
	**/
	T pop() {
		Fast k = head;
		if( k is null )
			return null;
		else {
			head = k.next;
			return k.elt;
		}
	}

	/**
		Tells if a list is empty.
	**/
	bool isEmpty() {
		return (head is null);
	}

	/**
		Remove the first element that is [== v] from the list.
		Returns [true] if an element was removed, [false] otherwise.
	**/
	bool remove(T v) {
		Fast prev = null;
		Fast l = head;
		while( l !is null ) {
			if( l.elt == v ) {
				if( prev is null )
					head = l.next;
				else
					prev.next = l.next;
				break;
			}
			prev = l;
			l = l.next;
		}
		return (l !is null);
	}
}