zip

Combine matching entries from objects.

Similar: cartesianProduct, zip.

function zip(xs, fm, fe, vd?)
// xs: objects
// fm: map function (vs, k)
// fe: end function (dones) [array.some]
// vd: default value

const object = require('extra-object');
const array  = require('extra-array');

var x = {a: 1, b: 2, c: 3};
var y = {a: 10, b: 20};
object.zip([x, y]);
// → { a: [ 1, 10 ], b: [ 2, 20 ] } (shortest)

object.zip([x, y], ([a, b]) => a + b);
// → { a: 11, b: 22 }

object.zip([x, y], null, array.some);
// → { a: [ 1, 10 ], b: [ 2, 20 ] } (shortest)

object.zip([x, y], null, array.every, 0);
// → { a: [ 1, 10 ], b: [ 2, 20 ], c: [ 3, 0 ] } (longest)

object.zip([x, y], null, array.head, 0);
// → { a: [ 1, 10 ], b: [ 2, 20 ], c: [ 3, 0 ] } (first)

References

• Data.List.zipWith: Haskell
• List-Extra.zip: elm
• zip: Python
• itertools.zip_longest: Python
• zip: Ruby
• _.zip: lodash
• _.zipWith: lodash
• Array.zip: sugarjs