var d3_array = d3_arraySlice; // conversion for NodeLists

function d3_arrayCopy(pseudoarray) {

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

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

  return array;

}

function d3_arraySlice(pseudoarray) {

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

}

try {

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

} catch(e) {

  d3_array = d3_arrayCopy;

}

var d3_arraySubclass = [].__proto__?

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

function(array, prototype) {

  array.__proto__ = prototype;

}:

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

function(array, prototype) {

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

};