1 var d3_array = d3_arraySlice; // conversion for NodeLists

     2 

     3 function d3_arrayCopy(pseudoarray) {

     4   var i = -1, n = pseudoarray.length, array = [];

     5   while (++i < n) array.push(pseudoarray[i]);

     6   return array;

     7 }

     8 

     9 function d3_arraySlice(pseudoarray) {

    10   return Array.prototype.slice.call(pseudoarray);

    11 }

    12 

    13 try {

    14   d3_array(document.documentElement.childNodes)[0].nodeType;

    15 } catch(e) {

    16   d3_array = d3_arrayCopy;

    17 }

    18 

    19 var d3_arraySubclass = [].__proto__?

    20 

    21 // Until ECMAScript supports array subclassing, prototype injection works well.

    22 function(array, prototype) {

    23   array.__proto__ = prototype;

    24 }:

    25 

    26 // And if your browser doesn't support __proto__, we'll use direct extension.

    27 function(array, prototype) {

    28   for (var property in prototype) array[property] = prototype[property];

    29 };