AI solution for JavaScript Coding Question on BFE.dev
1. implement curry()

Here is a possible implementation of the curry() function in JavaScript:

const curry = (fn) => {
  const arity = fn.length;
  return function curried(...args) {
    if (args.length >= arity) {
      return fn.apply(this, args);
    } else {
      return function (...moreArgs) {
        return curried.apply(this, args.concat(moreArgs));
      };
    }
  };
};

Let's break it down:

• The curry() function takes a function fn as its argument.
• It defines a variable arity that stores the expected number of arguments of fn.
• It returns an anonymous function that will be the curried version of fn.
• This anonymous function takes any number of arguments via the rest parameter ...args.
• If the number of arguments passed is greater than or equal to arity, it means that we have all the parameters we need to call fn, so we call it with fn.apply(this, args) and return the result.
• If the number of arguments passed is less than arity, we return another anonymous function that takes any number of additional arguments via the rest parameter ...moreArgs, and calls curried() recursively with the concatenation of args and moreArgs.

This implementation allows for partial application, meaning that we can call the curried function with some parameters, and get a new function that expects the remaining parameters. This can be useful for creating new functions from existing ones that have some parameters pre-filled.