Get all dom nodes from d3 selection - d3.js

Question

selection.node() returns only the first node. Can we get an array of all nodes from a selection?
EDIT Added some code to help us.
The attempt with each() is the only one producing the wanted
output, although quite verbose.
Calling sel[0] also returns an array with DOM nodes, but it's hacky (depends on the internal structure of the library) and includes an unwanted "parentNode" field.
// creating a selection to experiment with
var data= [1,2,3,4]
var sel = d3.select("li")
.data(data)
.enter().append("li").html(identity);
function identity(d){return d}
console.log(sel); // array[1] with array[4] with the <li>'s
// using .node()
var res1 = sel.node();
console.log(res1); // first <li> only
// using .each() to accumulate nodes in an array
var res2 = [];
function appendToRes2(){
res2.push(this);
}
sel.each(appendToRes2);
console.log(res2); // array[4] with the <li>'s (what I want)
// calling sel[0]
var res3 = sel[0];
console.log(res3); // array[4] with the <li>'s plus a "parentNode"
// #thisOneGuy's suggestion
var res4 = d3.selectAll(sel);
console.log(res4); // array[1] with array[1] with array[4] with the <li>'s
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>
EDIT 2 Why do I want to do that?
To call array methods like reduce and map on the DOM nodes. D3 provides filter but to use others I first need to extract the node array from the selection.

Answer 1

I originally wrote this as a comment, but decided to turn it into an answer...
It looks like d3 v4 will include the functionality you want. If you don't want to wait, you can steal the implementation now and add it to the selection prototype:
d3.selection.prototype.nodes = function(){
var nodes = new Array(this.size()), i = -1;
this.each(function() { nodes[++i] = this; });
return nodes;
}
Usage example:
d3.selection.prototype.nodes = function(){
var nodes = new Array(this.size()), i = -1;
this.each(function() { nodes[++i] = this; });
return nodes;
}
var data= [1,2,3,4]
var sel = d3.select("li")
.data(data)
.enter().append("li").html(identity);
function identity(d){return d}
console.log(sel.nodes());
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>
Since it came from #mbostock, it's a good bet is the best implementation available.