e44a7e37b6
git-svn-id: https://semanticscuttle.svn.sourceforge.net/svnroot/semanticscuttle/trunk@151 b3834d28-1941-0410-a4f8-b48e95affb8f
87 lines
3.5 KiB
JavaScript
87 lines
3.5 KiB
JavaScript
if(!dojo._hasResource["dojox.lang.functional.fold"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
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dojo._hasResource["dojox.lang.functional.fold"] = true;
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dojo.provide("dojox.lang.functional.fold");
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dojo.require("dojox.lang.functional.lambda");
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// This module adds high-level functions and related constructs:
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// - "fold" family of functions
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// Notes:
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// - missing high-level functions are provided with the compatible API:
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// foldl, foldl1, foldr, foldr1
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// - missing JS standard functions are provided with the compatible API:
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// reduce, reduceRight
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// Defined methods:
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// - take any valid lambda argument as the functional argument
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// - operate on dense arrays
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// - take a string as the array argument
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// - take an iterator objects as the array argument (only foldl, foldl1, and reduce)
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(function(){
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var d = dojo, df = dojox.lang.functional;
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d.mixin(df, {
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// classic reduce-class functions
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foldl: function(/*Array|String|Object*/ a, /*Function*/ f, /*Object*/ z, /*Object?*/ o){
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// summary: repeatedly applies a binary function to an array from left
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// to right using a seed value as a starting point; returns the final
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// value.
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if(typeof a == "string"){ a = a.split(""); }
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o = o || d.global; f = df.lambda(f);
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if(d.isArray(a)){
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for(var i = 0, n = a.length; i < n; z = f.call(o, z, a[i], i, a), ++i);
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}else{
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for(var i = 0; a.hasNext(); z = f.call(o, z, a.next(), i++));
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}
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return z; // Object
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},
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foldl1: function(/*Array|String|Object*/ a, /*Function|String|Array*/ f, /*Object?*/ o){
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// summary: repeatedly applies a binary function to an array from left
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// to right; returns the final value.
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if(typeof a == "string"){ a = a.split(""); }
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o = o || d.global; f = df.lambda(f);
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var z;
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if(d.isArray(a)){
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z = a[0];
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for(var i = 1, n = a.length; i < n; z = f.call(o, z, a[i], i, a), ++i);
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}else if(a.hasNext()){
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z = a.next();
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for(var i = 1; a.hasNext(); z = f.call(o, z, a.next(), i++));
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}
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return z; // Object
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},
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foldr: function(/*Array|String*/ a, /*Function|String|Array*/ f, /*Object*/ z, /*Object?*/ o){
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// summary: repeatedly applies a binary function to an array from right
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// to left using a seed value as a starting point; returns the final
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// value.
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if(typeof a == "string"){ a = a.split(""); }
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o = o || d.global; f = df.lambda(f);
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for(var i = a.length; i > 0; --i, z = f.call(o, z, a[i], i, a));
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return z; // Object
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},
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foldr1: function(/*Array|String*/ a, /*Function|String|Array*/ f, /*Object?*/ o){
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// summary: repeatedly applies a binary function to an array from right
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// to left; returns the final value.
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if(typeof a == "string"){ a = a.split(""); }
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o = o || d.global; f = df.lambda(f);
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var n = a.length, z = a[n - 1];
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for(var i = n - 1; i > 0; --i, z = f.call(o, z, a[i], i, a));
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return z; // Object
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},
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// JS 1.8 standard array functions, which can take a lambda as a parameter.
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reduce: function(/*Array|String|Object*/ a, /*Function*/ f, /*Object?*/ z){
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// summary: apply a function simultaneously against two values of the array
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// (from left-to-right) as to reduce it to a single value.
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return arguments.length < 3 ? df.foldl1(a, f) : df.foldl(a, f, z); // Object
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},
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reduceRight: function(/*Array|String*/ a, /*Function*/ f, /*Object?*/ z){
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// summary: apply a function simultaneously against two values of the array
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// (from right-to-left) as to reduce it to a single value.
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return arguments.length < 3 ? df.foldr1(a, f) : df.foldr(a, f, z); // Object
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}
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});
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})();
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}
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