map

Updates values based on map function.

iterable.map(x, fn, [ths]);
// x:   an iterable
// fn:  map function (v, i, x)
// ths: this argument

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

var x = [1, 2, 3, 4];
[...iterable.map(x, v => v * 2)];
// [2, 4, 6, 8]

references

• Array.prototype.map(): MDN web docs
• iterable_filter: PHP
• Data.List.map(): Haskell