unionKeys

Obtain keys present in any ientries.

Similar: unionKeys, intersectionKeys.

function unionKeys(...xs)
// xs: all ientries

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

var x = [["a", 1], ["b", 2], ["c", 3], ["d", 4]];
var y = [["b", 20], ["c", 30], ["e", 50]];
ientries.unionKeys(x, y);
// → Set(5) { "a", "b", "c", "d", "e" }

References

• Data.Set.union: Haskell
• Set.union: Python
• _.union: lodash
• _.unionBy: lodash
• _.unionWith: lodash
• Array.union: sugarjs