takeWhile - nodef/extra-iterable GitHub Wiki
Keep values from left, while a test passes.
Alternatives: take, takeRight, takeWhile, takeWhileRight. Similar: take, drop.
function takeWhile(x, ft)
// x: an iterable
// ft: test function (v, i, x)
const xiterable = require('extra-iterable');
var x = [1, 2, 3, 4, 5];
[...xiterable.takeWhile(x, v => v < 3)];
// → [1, 2]
[...xiterable.takeWhile(x, v => v < 4)];
// → [1, 2, 3]