8398c9048d
code was modified slightly, so the code differs from the original downloadable 1.9.5 version
93 lines
3 KiB
JavaScript
Executable file
93 lines
3 KiB
JavaScript
Executable file
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, ap = Array.prototype;
|
|
|
|
var currying = function(/*Object*/ info){
|
|
return function(){ // Function
|
|
var args = info.args.concat(ap.slice.call(arguments, 0));
|
|
if(arguments.length + info.args.length < info.arity){
|
|
return currying({func: info.func, arity: info.arity, args: args});
|
|
}
|
|
return info.func.apply(this, args);
|
|
};
|
|
};
|
|
|
|
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, l = a.length, args = new Array(l - 1), p = [], i = 1, t;
|
|
f = df.lambda(f);
|
|
for(; i < l; ++i){
|
|
t = a[i];
|
|
args[i - 1] = t;
|
|
if(t === df.arg){
|
|
p.push(i - 1);
|
|
}
|
|
}
|
|
return function(){ // Function
|
|
var t = ap.slice.call(args, 0), // clone the array
|
|
i = 0, l = p.length;
|
|
for(; i < l; ++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), i = 0, l = mix.length;
|
|
for(; i < l; ++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 = 0;
|
|
for(; i <= l; ++i){
|
|
t[l - i] = a[i];
|
|
}
|
|
return f.apply(this, t);
|
|
};
|
|
}
|
|
});
|
|
})();
|