PowerArray vs....

.gitignore

node_modules/

forEach.js

var PowerArray = require('PowerArray'),
    fast = require('fast.js'),
    _ = require('underscore')
    lodash = require('lodash');

var i,
  LEN = 1e7,
  array = Array();

function format(s) {
  return (s[0] * 1e3 + s[1] / 1e6) / 1e3;
}

function ops_per_sec(s) {
  return (LEN / format(s)).toExponential();
}

function report(s,t) {
  console.log(s+' complete in ' + format(t) + ', ops/s: ' + ops_per_sec(t));
}

function bench(s, fn, n) {
  var t = process.hrtime();
  fn();
  t = process.hrtime(t);
  var ops = ops_per_sec(t);
  n = n || ops;

  s += '\t' + format(t) + ' s\t' + ops + ' ops/s';
  s += '\t( '+Math.round((ops-n)/n*100, 2)+'% )'
  console.log(s);
  return ops;
}

function xbench(s) {
  //console.log(s+' (pending)');
};

function rand() {
  return Math.floor(Math.random() * 100 + 1);
}

for (i=0; i < LEN; i++) {
  var rnd = rand();
  array.push(rnd);

  var p = i/LEN*100;
  if (p % 10 === 0) {
    console.log(p+'% complete');
  }
}

var parray = new PowerArray(array);
var farray = new Float32Array(array);

var n = bench('array.forEach', function() {
  array.forEach(function (i) {
    i * 2;
  });
});

bench('Array.prototype.forEach on array', function() {
  Array.prototype.forEach.call(array,function (i) {
    i * 2;
  });
}, n);

bench('Array.prototype.forEach on Float32Array', function() {
  Array.prototype.forEach.call(farray,function (i) {
    i * 2;
  });
}, n);

bench('Array.prototype.forEach on PowerArray', function() {
  Array.prototype.forEach.call(parray, function (i) {
    i * 2;
  });
}, n);


bench('powerArray.forEach', function() {
  parray.forEach(function (i) {
    i * 2;
  });
}, n);

bench('fast.js on Array', function() {
  fast.forEach(array,function (i) {
    i * 2;
  });
}, n);

bench('fast.js on Float32Array', function() {
  fast.forEach(farray,function (i) {
    i * 2;
  });
}, n);

bench('fast.js on PowerArray', function() {
  fast.forEach(parray,function (i) {
    i * 2;
  });
}, n);

bench('underscore on Array', function() {
  _.forEach(array,function (i) {
    i * 2;
  });
}, n);

bench('underscore on Float32Array', function() {
  _.forEach(farray,function (i) {
    i * 2;
  });
}, n);

bench('lodash on Array', function() {
  lodash.forEach(array,function (i) {
    i * 2;
  });
}, n);

bench('lodash on Float32Array', function() {
  lodash.forEach(farray,function (i) {
    i * 2;
  });
}, n);

Results.txt

|                                         | time (s)    | ops/s    | %pct chg | 
| array.forEach                           | 0.695366052 | 1.44E+07	     | 
| Array.prototype.forEach on array        | 0.740159474 | 1.35E+07 |  -6.05% | 
| Array.prototype.forEach on Float32Array | 1.368684138 | 7.31E+06 | -49.19% | 
| Array.prototype.forEach on PowerArray   | 0.751636273 | 1.33E+07 |  -7.49% | 
| powerArray.forEach                      | 0.175532694 | 5.70E+07 | 296.15% | 
| fast.js on Array                        | 0.184384148 | 5.42E+07 | 277.13% | 
| fast.js on Float32Array                 | 6.121523157 | 1.63E+06 | -88.64% | 
| fast.js on PowerArray                   | 0.182967407 | 5.47E+07 | 280.05% | 
| underscore on Array                     | 0.179662224 | 5.57E+07 | 287.04% | 
| underscore on Float32Array              | 0.246603782 | 4.06E+07 | 181.98% | 
| lodash on Array                         | 0.182177956 | 5.49E+07 | 281.70% | 
| lodash on Float32Array                  | 0.245795857 | 4.07E+07 | 182.90% |