]> git.pond.sub.org Git - eow/blobdiff - static/dojo-release-1.1.1/dojox/lang/functional/curry.js
add Dojo 1.1.1
[eow] / static / dojo-release-1.1.1 / dojox / lang / functional / curry.js
diff --git a/static/dojo-release-1.1.1/dojox/lang/functional/curry.js b/static/dojo-release-1.1.1/dojox/lang/functional/curry.js
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+if(!dojo._hasResource["dojox.lang.functional.curry"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
+dojo._hasResource["dojox.lang.functional.curry"] = true;
+dojo.provide("dojox.lang.functional.curry");
+
+dojo.require("dojox.lang.functional.lambda");
+
+// This module adds high-level functions and related constructs:
+//     - currying and partial functions
+//     - argument pre-processing: mixer and flip
+
+// Acknoledgements:
+//     - partial() is based on work by Oliver Steele 
+//             (http://osteele.com/sources/javascript/functional/functional.js)
+//             which was published under MIT License
+
+// Defined methods:
+//     - take any valid lambda argument as the functional argument
+
+(function(){
+       var df = dojox.lang.functional;
+
+       var currying = function(/*Object*/ info){
+               return function(){      // Function
+                       if(arguments.length + info.args.length < info.arity){
+                               return currying({func: info.func, arity: info.arity, 
+                                       args: Array.prototype.concat.apply(info.args, arguments)});
+                       }
+                       return info.func.apply(this, Array.prototype.concat.apply(info.args, arguments));
+               };
+       };
+
+       dojo.mixin(df, {
+               // currying and partial functions
+               curry: function(/*Function|String|Array*/ f, /*Number?*/ arity){
+                       // summary: curries a function until the arity is satisfied, at 
+                       //      which point it returns the calculated value.
+                       f = df.lambda(f);
+                       arity = typeof arity == "number" ? arity : f.length;
+                       return currying({func: f, arity: arity, args: []});     // Function
+               },
+               arg: {},        // marker for missing arguments
+               partial: function(/*Function|String|Array*/ f){
+                       // summary: creates a function where some arguments are bound, and
+                       //      some arguments (marked as dojox.lang.functional.arg) are will be 
+                       //      accepted by the final function in the order they are encountered.
+                       // description: This method is used to produce partially bound 
+                       //      functions. If you want to change the order of arguments, use
+                       //      dojox.lang.functional.mixer() or dojox.lang.functional.flip().
+                       var a = arguments, args = new Array(a.length - 1), p = [];
+                       f = df.lambda(f);
+                       for(var i = 1; i < a.length; ++i){
+                               var t = a[i];
+                               args[i - 1] = t;
+                               if(t == df.arg){
+                                       p.push(i - 1);
+                               }
+                       }
+                       return function(){      // Function
+                               var t = Array.prototype.slice.call(args, 0); // clone the array
+                               for(var i = 0; i < p.length; ++i){
+                                       t[p[i]] = arguments[i];
+                               }
+                               return f.apply(this, t);
+                       };
+               },
+               // argument pre-processing
+               mixer: function(/*Function|String|Array*/ f, /*Array*/ mix){
+                       // summary: changes the order of arguments using an array of
+                       //      numbers mix --- i-th argument comes from mix[i]-th place
+                       //      of supplied arguments.
+                       f = df.lambda(f);
+                       return function(){      // Function
+                               var t = new Array(mix.length);
+                               for(var i = 0; i < mix.length; ++i){
+                                       t[i] = arguments[mix[i]];
+                               }
+                               return f.apply(this, t);
+                       };
+               },
+               flip: function(/*Function|String|Array*/ f){
+                       // summary: changes the order of arguments by reversing their
+                       //      order.
+                       f = df.lambda(f);
+                       return function(){      // Function
+                               // reverse arguments
+                               var a = arguments, l = a.length - 1, t = new Array(l + 1), i;
+                               for(i = 0; i <= l; ++i){
+                                       t[l - i] = a[i];
+                               }
+                               return f.apply(this, t);
+                       };
+               }
+       });
+})();
+
+}