Iterable higher order functions so that they play well with comprehensions

prelude-generators.js

Number.prototype[Symbol.iterator] = function* (startIdx = 0) {
  const endIdx = this.valueOf()
  let i = startIdx

  while (i < endIdx) {
    yield i++
  }
}

//console.log([...8]); // [0,1,2,3,4,5,6,7]
//for (let x of 8) console.log(x); // 0 1 2 3 4 5 6 7
//[...7[Symbol.iterator](4)] // [4,5,6]

// and :: (a -> Bool) -> (b -> Bool) -> (a -> b -> Bool)
function and(f, g) {
  return function(a, b){
    return f(a) && f(b);
  }
}



// zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
function* zipWith(f, a, b){
  var i = 0;
  while(i < a.length && i < b.length)  yield f(a[i], b[i]), i++;
}

//let m = [for (x of zipWith((a, b) => a + b, [1,2,3], [4,5])) x]
//console.log(m)