Helpers as nodes

[thekid]

This pull request changes the block helpers from builtin helpers over to specialized BlockHelper nodes, and boosts performance enormously:

<?php
use util\profiling\Timer;
use com\handlebarsjs\HandlebarsEngine;
use com\github\mustache\DataContext;

class Benchmark extends \util\cmd\Command {

  public function run() {

    // Fixtures
    $data= array('person' => array('name' => 'World'));
    $template= 'Hello, {{#if person}}{{#with person}}{{name}}{{/with}}{{/if}}';
    $times= 100000;

    // Code
    $engine= new HandlebarsEngine();
    $compiled= $engine->compile($template);
    $context= create(new DataContext($data))->withEngine($engine);
    $t= Timer::measure(function() use($times, $engine, $compiled, $context) {
      for ($i= 0; $i < $times; $i++) {
        $compiled->evaluate($context);
      }
    });
    $this->out->writeLine($engine->evaluate($compiled, $context));
    $this->out->writeLinef('%d times, %.3f seconds', $times, $t->elapsedTime());
  }
}

master

$ xpcli Benchmark.class.php
Hello, World
100000 times, 9.802 seconds

helpers-as-nodes

$ xpcli Benchmark.class.php
Hello, World
100000 times, 2.090 seconds

[thekid]

Still roughly for to tive times slower that its NodeJS equivalent, though:

Handlebars= require('handlebars');

// Fixtures
var template = 'Hello, {{#if person}}{{#with person}}{{name}}{{/with}}{{/if}}';
var context = {person : { name : 'World'}};
var times= 100000;

// Code
var compiled = Handlebars.compile(template);
var start= new Date().getTime();
for (var i= 0; i < times; i++) {
  compiled(context);
}
console.log(compiled(context));
console.log('%d runs, %s seconds', times, (new Date().getTime() - start) / 1000);

$ node benchmark.js
Hello, World
100000 runs, 0.489 seconds