ZipArray

Provides an alternative Apply implementation for arrays.

Installation

npm install ziparray

Motivation

The common implementation of Apply for arrays works with all combinations. However, there is another implementation of Apply for arrays that works in "pairwise" fashion. You can think of this as a data type level encoding of the zip family of functions. Encoding the effect ("pairwise" application) in the data type allows us to write code that expresses our intentions better.

Usage

Fantasy Land

> const {ZipArray} = require('ziparray');
undefined
> ZipArray([1,2,3])
ZipArray([1,2,3])
> ZipArray([1,2,3]).map(x => x * 10)
ZipArray([10,20,30])
> ZipArray([x => x + 1, x => x * 3]).ap(ZipArray([1,2,3]))
ZipArray([2,6])
> ZipArray([x => x + 1, x => x * 3]).ap(ZipArray([1,2]))
ZipArray([2,6])
> ZipArray([x => y => x + y, x => y => x * y]).ap(ZipArray([1,20])).ap(ZipArray([3,40]))
ZipArray([4,800])

Static Land

> const ZipArray = require('.');
undefined
> const {map, ap} = ZipArray;
undefined
> map(x => x + 10, [1,2,3])
[ 11, 12, 13 ]
> ap([x => x + 1, x => x * 3], [1,2,3])
[ 2, 6 ]
> ap([x => x + 1, x => x * 3], [1,2])
[ 2, 6 ]
> ap(ap([x => y => x + y, x => y => x * y], [1,20]), [3,40])
[ 4, 800 ]