(function ( $ ) {
var methods = {
// $([1,2,3]).collect(function() { return this * this }) // => [1, 4, 9]
collect: function(enumerable, callback) {
var result = [];
$.each(enumerable, function(index) {
result.push(callback.call(this, index));
});
return result;
},
// $([1,2,3]).inject(0, function(a) { return a + this }) // => 6
inject: function(enumerable, initialValue, callback) {
var accumulator = initialValue;
$.each(enumerable, function (index) {
accumulator = callback.call(this, accumulator, index);
});
return accumulator;
},
// $([1,2,3]).select(function() { return this % 2 == 1 }) // => [1, 3]
select: function(enumerable, callback) {
var result = [];
$.each(enumerable, function(index) {
if (callback.call(this, index))
result.push(this);
});
return result;
},
// $([1,2,3]).reject(function() { return this % 2 == 1 }) // => [2]
reject: function(enumerable, callback) {
return $.select(enumerable, negate(callback));
},
// $([1,2]).any(function() { return this == 1 }) // => true
any: function(enumerable, callback) {
return $.inject(enumerable, false, function(accumulator, index) {
return accumulator || callback.call(this, index);
});
},
// $([1,1]).any(function() { return this == 1 }) // => true
all: function(enumerable, callback) {
return $.inject(enumerable, true, function(accumulator, index) {
return accumulator && callback.call(this, index);
});
},
// $([1,2,3]).sum() // => 6
sum: function(enumerable) {
return $.inject(enumerable, 0, function(accumulator) {
return accumulator + this;
});
}
};
var staticFunctions = {};
var iteratorFunctions = {};
$.each( methods, function(name, f){
staticFunctions[name] = makeStaticFunction(f);
iteratorFunctions[name] = makeIteratorFunction(staticFunctions[name]);
});
$.extend(staticFunctions);
$.fn.extend(iteratorFunctions);
// Private methods
function makeStaticFunction(f) {
return function() {
if (arguments.length > 1) // The first argument is the enumerable
validateCallback(arguments[arguments.length - 1]);
return f.apply(this, arguments);
}
}
function makeIteratorFunction(staticFunction) {
return function() {
// arguments isn't a real array, concat doesn't work
// unless you explicitly convert it
function toArray() {
var result = []
for (var i = 0; i < this.length; i++)
result.push(this[i])
return(result)
}
return staticFunction.apply(this, [this].concat(toArray.apply(arguments)))
}
}
function validateCallback(callback) {
if (!jQuery.isFunction(callback))
throw("callback needs to be a function, it was: " + callback);
}
function negate(f) {
return function() {
return !f.apply(this, arguments)
}
}
})( jQuery );
