lazyIter.js

JavaScript asynchronous lazy loops.

These iterators are the minimum version of Pot.js's iterators.
Pot.js : http://polygonplanet.github.com/Pot.js/

lazyIter CPU usage tester: http://polygonplanet.github.com/lazyIter.js/lazyiter.js-cpu-usage-tester.html

lazyIter Test fiddle: http://jsfiddle.net/polygonplanet/JLT2r/

Usage:

---

// forEach:
//
// lazyIter.forEach(object, func, callback [, speed [, context]])

// Array.
lazyIter.forEach(['a', 'b', 'c'], function(val, i) {
  console.log(i + ':' + val);
}, function() {
  console.log('End loop');
});
// result:
//   '0:a'
//   '1:b'
//   '2:c'
//   'End loop'

// Object.
lazyIter.forEach({a: 1, b: 2, c: 3}, function(val, key) {
  console.log(key + ':' + val);
}, function() {
  console.log('End loop');
});
// result:
//   'a:1'
//   'b:2'
//   'c:3'
//   'End loop'

---

// repeat:
//
// lazyIter.repeat(max, func, callback [, speed [, context]])

// Specify as number.
lazyIter.repeat(10, function(i) {
  console.log(i);
}, function() {
  console.log('End loop');
});
// result:
//   0
//   1
//   ...
//   9
//   'End loop'

// Specify first, step and end number like for statement.
lazyIter.repeat({begin: 0, step: 5, end: 30}, function(i) {
  console.log(i);
}, function() {
  console.log('End loop');
});
// result:
//   0
//   5
//   10
//   15
//   20
//   25
//   'End loop'

---

// forEver:
//
// lazyIter.forEver(func, callback [, speed [, context]])

var end = 10;
lazyIter.forEver(function(i) {
  if (i === end) {
    throw lazyIter.StopIteration;
  }
  console.log(i);
}, function() {
  console.log('End loop');
});
// result:
//   0
//   1
//   ...
//   9
//   'End loop'

You can stop each iterations by "throw lazyIter.StopIteration;".
An argument "context" will be used as "this" in callback function.
You can specify iteration "speed" by following types:

• 'ninja' : fastest
• 'rapid' : faster
• 'fast' : fast
• 'normal' : normal (default)
• 'slow' : slowly
• 'doze' : more slowly
• 'limp' : most slowly