MixedTupleMap

A memory-efficient Map which accepts multiple objects as a key. This lib is one of the several possible cache for memoize-immutable, but it can suit other use-cases as it implements a usual Map API.

Install

npm install --save MixedTupleMap

This lib has no dependency, but requires a native implementation of WeakMap.

Usage

Restrictions. This map should be used when:

var MixedTupleMap = require('MixedTupleMap');
 
var cache = new MixedTupleMap();
 
var keyPart1 = {};
var keyPart2 = 'yolo';
var keyPart3 = [];
var value = {any: 'thing'};
 
// Note that following keyPart tuples are wrapped in new arrays that are !==
// (otherwise a WeakMap would have been enough).
cache.set([keyPart1, keyPart2, keyPart3], value);
 
cache.has([keyPart1, keyPart2, keyPart3]) === true;
cache.get([keyPart1, keyPart2, keyPart3]) === value;

When should you use this map?

This map is the best alternative to a WeakMap, when you need keys composed of multiple parts that mix primitive and non-primitive types. Note shouldn't be used if ALL parts of the key are likely to have primitive types (number, string, boolean, undefined or even null).

Author

@louis_remi

License

MPL-2.0