Exploration of Curry-ing function in JavaScript

README.md

Curry-ing Functions In JavaScript

I don't know why, but this morning I felt like exploring function curry-ing and writing a little bit about it. First I watched a video on curry-ing from the JS Weekly newletter. Then I wanted to write my own implementation. After that I thought I would share what I did with my team at work and then this.

Brain-dump over.

The only reason I created two different implementations is becuase semantically I think that a function is only curried once; as I understand it - to curry - is a process by which you convert a single function which takes multiple arguments into a series of multiple functions each taking exactly one argument.

So, while the implementations work identically from the point of view of the user the differ in their implementation; basically only semantically.

curry-apply.js

function curry (...setup) {
  function apply (fn, ...pre) {

    return pre.length < fn.length
      ? (...post) => apply(fn, ...pre.concat(post))
      : fn(...pre);
  }
  
  return apply(setup.shift(), ...setup);
}

curry-simple.js

function curry (fn, ...pre) {
  
  return pre.length < fn.length
    ? (...post) => curry(fn, ...pre.concat(post))
    : fn(...pre);
}