Partial function application: Difference between revisions

fsf1 = fs(f1),

fsf2 = fs(f2);

// TEST -------------------------------------------------------------------

return [

fsf1([0, 1, 2, 3]),

fsf2([0, 1, 2, 3]),

fsf1([2, 4, 6, 8]),

fsf2([2, 4, 6, 8])

];

})();</lang>

{{Out}}

<pre>[[0, 2, 4, 6], [0, 1, 4, 9], [4, 8, 12, 16], [4, 16, 36, 64]]</pre>

The simple version of the higher-order '''curry''' function above works only on functions with two arguments. For more flexibility, we can generalise it to a form which curries functions with an arbitrary number of arguments:

<lang JavaScript>(() => {

'use strict';

// GENERIC FUNCTIONS ------------------------------------------------------

// 2 or more arguments

// curry :: Function -> Function

const curry = (f, ...args) => {

const go = xs => xs.length >= f.length ? (f.apply(null, xs)) :

function () {

return go(xs.concat([].slice.apply(arguments)));

};

return go([].slice.call(args, 1));

};

// map :: (a -> b) -> [a] -> [b]

const map = curry((f, xs) => xs.map(f));

// PARTIAL APPLICATION ----------------------------------------------------

const

f1 = x => x * 2,

f2 = x => x * x,

fs = map,