A function fromTo that produces a generator, that will produce values in a range.

fromTo.js

/* ---
Write a function fromTo that produces a generator, that will produce values in a range.
Source: https://buttondown.email/cassidoo/archive/if-everything-was-perfect-you-would-never-learn/
*/

function fromTo(start, end) {
    let value = start
    return function () {
        if (value <= end) {
            return value++
        } 
    }
}

/*
let gen = fromTo(5, 7)
console.log(gen()) // 5
console.log(gen()) // 6
console.log(gen()) // 7
console.log(gen()) // undefined

*/