interlude

Functional JavaScript library

Interlude

Interlude is a functional ES6 based JavaScript library inspired by Haskell. It's aims to simplify and abstract common patterns by providing a set of common higher order functions.

Use it with qualified imports with the yet unfinished module import syntax or attach it to the short variable of choice. For selling points, here's how it will look with ES7 modules.

import { range, pow, times, all, eq, comparing, zipWith, zipWith3, iterate, gcd, uniqueBy, iterate, interval } from 'interlude'
 
range(5).map(pow(2));
// [ 1, 4, 9, 16, 25 ] 
 
var nested = [ [ 1, 3, 2 ], [ 2, 2 ], [ 1, 4, 2, 3 ] ];
nested.filter(all(eq(2)));
// [ [2, 2] ] 
 
// outer sort by property 
nested.sort(comparing('length'));
// [ [ 2, 2 ], [ 1, 3, 2 ], [ 1, 4, 2, 3 ] ] 
 
zipWith3((x, y, z) => x + y + z, [1,1,1,1,1], range(5), [1,0,0]);
// [ 3, 3, 4 ] 
 
// Powers of two 
iterate(8, 2, times(2));
// [ 2, 4, 8, 16, 32, 64, 128, 256 ] 
 
// Pascal's Triangle 
var pascalNext = (row) => zipWith((x, y) => x + y, row.concat(0), [0].concat(row));
 
iterate(6, [1], pascalNext);
// [ [ 1 ], 
//   [ 1, 1 ], 
//   [ 1, 2, 1 ], 
//   [ 1, 3, 3, 1 ], 
//   [ 1, 4, 6, 4, 1 ], 
//   [ 1, 5, 10, 10, 5, 1 ] ] 
 
// Prime numbers 
var notCoprime = (x, y) => gcd(x, y) > 1;
uniqueBy(notCoprime, interval(2, 20));
// [ 2, 3, 5, 7, 11, 13, 17, 19 ] 

Interlude is merely a stable front for three re-exported modules:

interlude
├─── autonomy
├─── operators
└─── subset

These modules are of course requirable by themselves, and we encourage you to require them directly. The submodules are small (<150 lines each) and focused.

Regardless, you should read their short and independent APIs:

Additionally, two extra modules (which were not included in interlude due to their smaller likelihood of use) are also good fits. They do not overlap in API, and are highly recommended when needed. You may wish to read their short APIs as well.

$ npm install interlude

MIT-Licensed. See LICENSE file for details.