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