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A JavaScript implementation of curry.
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(function(){ | |
"use strict"; | |
/** | |
* A factory for creating curry functions that | |
* are tied to the arrity of the function f. | |
*/ | |
function makeArrityBasedCurry(n) { | |
var curry = function(f){ | |
var args = [].slice.call(arguments, 1); | |
//Enforce f must be a function. | |
if(typeof f !== "function"){ | |
throw new Error("f must be a function"); | |
} | |
return function(){ | |
var largs = args.concat([].slice.call(arguments, 0)); | |
if(largs.length >= n){ | |
return f.apply(this, largs); | |
}else{ | |
largs.unshift(f); | |
return curry.apply(this, largs); | |
} | |
}; | |
}; | |
return curry; | |
} | |
/** | |
* Augment Function's prototype to support creating curried functions. | |
*/ | |
Function.prototype.curry = function(nParams){ | |
//If nParams is not provided ask "this" how many parameters it has. | |
var arrity = nParams ? nParams : this.length; | |
return makeArrityBasedCurry(arrity)(this); | |
}; | |
/** | |
* A function to be curried. | |
* It is expecting 4 arguments when it is called. | |
*/ | |
var curry4 = function f(a, b, c, d) { | |
return a + b + c + d; | |
}.curry(); | |
/** | |
* Make a curry whose target function f has an arity of 4. | |
*/ | |
var result; | |
result = curry4(1)(2, 3, 4); | |
console.log(result); | |
result = curry4(1, 2)(3, 4); | |
console.log(result); | |
result = curry4(1, 2, 3)(4); | |
console.log(result); | |
result = curry4(1, 2, 3, 4); | |
console.log(result); | |
/// Since curry4 returns a function it can also be used as follows. | |
result = curry4(1)(1)(1)(1); | |
console.log(result); | |
}()); |
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