union

Gives values present in any iterable. 🏃 [:vhs:] 📦 🌔 📒

Alternatives: compare, map.

iterable.union(x, y, [fc], [fm]);
// x:  an iterable
// y:  another iterable
// fc: compare function (a, b)
// fm: map function (v, i, x)

⏱️ Compare function => O(n²).

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

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

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

[...iterable.union(x, y, null, v => Math.abs(v))];
// [ 1, 2, 3, 4, -5 ]

references

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