JS.Enumerable = new JS.Module({
extend: {
forEach: function(block, context) {
for (var i = 0, n = this.length; i < n; i++)
block.call(context || null, this[i], i);
},
isComparable: function(list) {
return list.all(function(item) {
return JS.isFn(item.compareTo);
});
},
Collection: new JS.Class({
initialize: function(array) {
this.length = 0;
var push = Array.prototype.push;
JS.Enumerable.forEach.call(array, function(item) {
push.call(this, item);
}, this);
}
})
},
all: function(block, context) {
var truth = true;
this.forEach(function(item, i) {
truth = truth && block.call(context || null, item, i);
});
return !!truth;
},
any: function(block, context) {
var truth = false;
this.forEach(function(item, i) {
truth = truth || block.call(context || null, item, i);
});
return !!truth;
},
forEachCons: function(n, block, context) {
var entries = this.entries(), size = entries.length, limit = size - n;
for (var i = 0; i <= limit; i++)
block.call(context || null, entries.slice(i, i+n), i);
},
forEachSlice: function(n, block, context) {
var entries = this.entries(), size = entries.length, m = Math.ceil(size/n);
for (var i = 0; i < m; i++)
block.call(context || null, entries.slice(i*n, (i+1)*n), i);
},
find: function(block, context) {
var needle = {}, K = needle;
this.forEach(function(item, i) {
if (needle != K) return;
needle = block.call(context || null, item, i) ? item : needle;
});
return needle == K ? null : needle;
},
inject: function(memo, block, context) {
var counter = 0, K = {};
if (JS.isFn(memo)) {
context = block; block = memo; memo = K;
}
this.forEach(function(item, i) {
if (!counter++ && memo === K) return memo = item;
memo = block.call(context || null, memo, item, i);
});
return memo;
},
map: function(block, context) {
var map = [];
this.forEach(function(item, i) {
map.push(block.call(context || null, item, i));
});
return map;
},
max: function(block, context) {
var list = this.sort(block, context);
return list[list.length - 1];
},
member: function(needle) {
return this.any(function(item) { return item == needle; });
},
min: function(block, context) {
var list = this.sort(block, context);
return list[0];
},
partition: function(block, context) {
var ayes = [], noes = [];
this.forEach(function(item, i) {
(block.call(context || null, item, i) ? ayes : noes).push(item);
});
return [ayes, noes];
},
reject: function(block, context) {
var map = [];
this.forEach(function(item, i) {
if (!block.call(context || null, item, i)) map.push(item);
});
return map;
},
select: function(block, context) {
var map = [];
this.forEach(function(item, i) {
if (block.call(context || null, item, i)) map.push(item);
});
return map;
},
sort: function(block, context) {
var comparable = JS.Enumerable.isComparable(this), entries = this.entries();
block = block || (comparable
? function(a,b) { return a.compareTo(b); }
: null);
return block
? entries.sort(function(a,b) { return block.call(context || null, a, b); })
: entries.sort();
},
sortBy: function(block, context) {
var util = JS.Enumerable;
var map = new util.Collection(this.map(block, context));
var comparable = util.isComparable(map);
return new util.Collection(map.zip(this).sort(function(a, b) {
a = a[0]; b = b[0];
return comparable ? a.compareTo(b) : (a < b ? -1 : (a > b ? 1 : 0));
})).map(function(item) { return item[1]; });
},
toArray: function() {
return this.map(function(x) { return x; });
},
zip: function() {
var util = JS.Enumerable;
var args = [], counter = 0, n = arguments.length, block, context;
if (arguments[n-1] instanceof Function) {
block = arguments[n-1]; context = {};
}
if (arguments[n-2] instanceof Function) {
block = arguments[n-2]; context = arguments[n-1];
}
util.forEach.call(arguments, function(arg) {
if (arg == block || arg == context) return;
if (arg.toArray) arg = arg.toArray();
if (arg instanceof Array) args.push(arg);
});
var results = this.map(function(item) {
var zip = [item];
util.forEach.call(args, function(arg) {
zip.push(arg[counter] === undefined ? null : arg[counter]);
});
return ++counter && zip;
});
if (!block) return results;
util.forEach.call(results, block, context);
}
});
// http://developer.mozilla.org/en/docs/index.php?title=Core_JavaScript_1.5_Reference:Global_Objects:Array&oldid=58326
JS.Enumerable.include({
forEach: JS.Enumerable.forEach,
collect: JS.Enumerable.instanceMethod('map'),
detect: JS.Enumerable.instanceMethod('find'),
entries: JS.Enumerable.instanceMethod('toArray'),
every: JS.Enumerable.instanceMethod('all'),
findAll: JS.Enumerable.instanceMethod('select'),
filter: JS.Enumerable.instanceMethod('select'),
some: JS.Enumerable.instanceMethod('any')
});
JS.Enumerable.Collection.include(JS.Enumerable);
