@pinemach/obj-permute

@pinemach/obj-permute

@pinemach/obj-permute is a small JavaScript package which can be used to iterate the list of objects representing every combination of attribute values as specified by an input object whose attributes refer to lists of possible values.

You can read the full API documentation at pineapplemachine.github.io/obj-permute-js/.

Installation

You can install this package with the package manager of your choice. For example,

npm install @pinemach/obj-permute

You can then import and use the module like so:

// CommonJS
const getObjectPermutations = require("@pinemach/obj-permute").getObjectPermutations;

// ES6 modules
import getObjectPermutations from "@pinemach/obj-permute";

Usage

This package exports the getObjectPermutations function, which accepts an object whose attributes associate keys with lists of values.

The function returns an iterator which enumerates objects representing every combination of attribute values within those lists.

For example, the states object input {x: [0, 1], y: [2, 3]} corresponds to the list of permutations containing the objects {x: 0, y: 2}, {x: 1, y: 2}, {x: 0, y: 3}, and {x: 1, y: 3}.

import getObjectPermutations from "@pinemach/obj-permute";

// Get an iterator for every combination of attribute values
const permutations = getObjectPermutations({
    x: [0, 1],
    y: [2, 3],
});

// Get an array from that iterator
const permutationsArray = permutations.array();

// Verify that each expected item is present
assert(permutationsArray.length === 4);
assert(permutationsArray.find(
    result => result.x === 0 && result.y === 2
));
assert(permutationsArray.find(
    result => result.x === 1 && result.y === 2
));
assert(permutationsArray.find(
    result => result.x === 0 && result.y === 3
));
assert(permutationsArray.find(
    result => result.x === 1 && result.y === 3
));