union

Gives values present in any iterable.

Alternatives: compare, map.

iterable.union(x, y, [fn]);
// x:  an iterable
// y:  another iterable
// fn: compare function (a, b)

const iterable = require('extra-iterable');

var x = [1, 2, 3, 4];
[...iterable.union(x, [2, 3, 5])];
// [1, 2, 3, 4, 5]

var x = [1, 2, 3, 4];
[...iterable.union(x, [-2, -3, -5], (a, b) => Math.abs(a) - Math.abs(b))];
// [1, 2, 3, 4, -5]

references

• _.union(): lodash
• Data.Set.union(): Haskell
• Set.union(): Python