source: Dev/trunk/src/client/dojox/lang/functional/array.js

define(["dojo/_base/kernel", "dojo/_base/lang", "dojo/_base/array", "./lambda"],
        function(kernel, lang, arr, df){

// This module adds high-level functions and related constructs:
//      - array-processing functions similar to standard JS functions

// Notes:
//      - this module provides JS standard methods similar to high-level functions in dojo/_base/array.js:
//              forEach, map, filter, every, some

// Defined methods:
//      - take any valid lambda argument as the functional argument
//      - operate on dense arrays
//      - take a string as the array argument
//      - take an iterator objects as the array argument

        var empty = {};

        lang.mixin(df, {
                // JS 1.6 standard array functions, which can take a lambda as a parameter.
                // Consider using dojo._base.array functions, if you don't need the lambda support.
                filter: function(/*Array|String|Object*/ a, /*Function|String|Array*/ f, /*Object?*/ o){
                        // summary:
                        //              creates a new array with all elements that pass the test
                        //              implemented by the provided function.
                        if(typeof a == "string"){ a = a.split(""); }
                        o = o || kernel.global; f = df.lambda(f);
                        var t = [], v, i, n;
                        if(lang.isArray(a)){
                                // array
                                for(i = 0, n = a.length; i < n; ++i){
                                        v = a[i];
                                        if(f.call(o, v, i, a)){ t.push(v); }
                                }
                        }else if(typeof a.hasNext == "function" && typeof a.next == "function"){
                                // iterator
                                for(i = 0; a.hasNext();){
                                        v = a.next();
                                        if(f.call(o, v, i++, a)){ t.push(v); }
                                }
                        }else{
                                // object/dictionary
                                for(i in a){
                                        if(!(i in empty)){
                                                v = a[i];
                                                if(f.call(o, v, i, a)){ t.push(v); }
                                        }
                                }
                        }
                        return t;       // Array
                },
                forEach: function(/*Array|String|Object*/ a, /*Function|String|Array*/ f, /*Object?*/ o){
                        // summary:
                        //              executes a provided function once per array element.
                        if(typeof a == "string"){ a = a.split(""); }
                        o = o || kernel.global; f = df.lambda(f);
                        var i, n;
                        if(lang.isArray(a)){
                                // array
                                for(i = 0, n = a.length; i < n; f.call(o, a[i], i, a), ++i);
                        }else if(typeof a.hasNext == "function" && typeof a.next == "function"){
                                // iterator
                                for(i = 0; a.hasNext(); f.call(o, a.next(), i++, a));
                        }else{
                                // object/dictionary
                                for(i in a){
                                        if(!(i in empty)){
                                                f.call(o, a[i], i, a);
                                        }
                                }
                        }
                        return o;       // Object
                },
                map: function(/*Array|String|Object*/ a, /*Function|String|Array*/ f, /*Object?*/ o){
                        // summary:
                        //              creates a new array with the results of calling
                        //              a provided function on every element in this array.
                        if(typeof a == "string"){ a = a.split(""); }
                        o = o || kernel.global; f = df.lambda(f);
                        var t, n, i;
                        if(lang.isArray(a)){
                                // array
                                t = new Array(n = a.length);
                                for(i = 0; i < n; t[i] = f.call(o, a[i], i, a), ++i);
                        }else if(typeof a.hasNext == "function" && typeof a.next == "function"){
                                // iterator
                                t = [];
                                for(i = 0; a.hasNext(); t.push(f.call(o, a.next(), i++, a)));
                        }else{
                                // object/dictionary
                                t = [];
                                for(i in a){
                                        if(!(i in empty)){
                                                t.push(f.call(o, a[i], i, a));
                                        }
                                }
                        }
                        return t;       // Array
                },
                every: function(/*Array|String|Object*/ a, /*Function|String|Array*/ f, /*Object?*/ o){
                        // summary:
                        //              tests whether all elements in the array pass the test
                        //              implemented by the provided function.
                        if(typeof a == "string"){ a = a.split(""); }
                        o = o || kernel.global; f = df.lambda(f);
                        var i, n;
                        if(lang.isArray(a)){
                                // array
                                for(i = 0, n = a.length; i < n; ++i){
                                        if(!f.call(o, a[i], i, a)){
                                                return false;   // Boolean
                                        }
                                }
                        }else if(typeof a.hasNext == "function" && typeof a.next == "function"){
                                // iterator
                                for(i = 0; a.hasNext();){
                                        if(!f.call(o, a.next(), i++, a)){
                                                return false;   // Boolean
                                        }
                                }
                        }else{
                                // object/dictionary
                                for(i in a){
                                        if(!(i in empty)){
                                                if(!f.call(o, a[i], i, a)){
                                                        return false;   // Boolean
                                                }
                                        }
                                }
                        }
                        return true;    // Boolean
                },
                some: function(/*Array|String|Object*/ a, /*Function|String|Array*/ f, /*Object?*/ o){
                        // summary:
                        //              tests whether some element in the array passes the test
                        //              implemented by the provided function.
                        if(typeof a == "string"){ a = a.split(""); }
                        o = o || kernel.global; f = df.lambda(f);
                        var i, n;
                        if(lang.isArray(a)){
                                // array
                                for(i = 0, n = a.length; i < n; ++i){
                                        if(f.call(o, a[i], i, a)){
                                                return true;    // Boolean
                                        }
                                }
                        }else if(typeof a.hasNext == "function" && typeof a.next == "function"){
                                // iterator
                                for(i = 0; a.hasNext();){
                                        if(f.call(o, a.next(), i++, a)){
                                                return true;    // Boolean
                                        }
                                }
                        }else{
                                // object/dictionary
                                for(i in a){
                                        if(!(i in empty)){
                                                if(f.call(o, a[i], i, a)){
                                                        return true;    // Boolean
                                                }
                                        }
                                }
                        }
                        return false;   // Boolean
                }
        });
        
        return df;
});