implement zip

collection 1	collection 2	collection 3	result
1	a	fish	(1, a, fish)
2	b	pita	(2, b, pita)
3		cheese
4

const zip = function * (...collections) {
    const iterators = collections.map(c => c[symbol.iterator]());
    while(true) {
        const nexts = iterators.map(i => i.next())
        if(nexts.some(n => n.done))
            return
        yield nexts.map(n => n.value)
    }
}

const col = (index) => example.map(x => x[index]).filter(x => x)

return [...zip(col(0), col(1), col(2) )]

implement zip-longest

collection 1	collection 2	collection 3	result
1	a	fish	(1, a, fish)
2	b	pita	(2, b, pita)
3		cheese	(3, _, cheese)
4			(4, _, _)

const zipLongest = function * (padWith, ...collections) {
    const iterators = collections.map(c => c[Symbol.iterator]());
    while(true) {
        const nexts = iterators.map(i => i.next())
        if(nexts.every(n => n.done))
            return
        yield nexts.map(n => n.done ? padWith : n.value)
    }
}

const col = (index) => example.map(x => x[index]).filter(x => x)

return [...zipLongest(`_`, col(0), col(1), col(2) )]