trie-memoize

A memoization algorithm in which each function argument represents a new key in a mapping, creating a trie of caches - the depth of which defined by your setup. As such, it is incredibly fast with O(n arguments) lookup performance and very memory-efficient when structures like WeakMaps are used.

This memoization function only works for functions where the exact number of arguments is known and constant.

Installation

yarn add trie-memoize or npm i trie-memoize

Usage

const m1 = memoize([{}], v => v.toUpperCase())
m1('foo')  // FOO uncached
m1('foo')  // FOO cached
const m2 = memoize([{}, Map], (v1, v2) => `${v1}-${v2}`)
m2('foo', 'bar')  // foo-bar, uncached
m2('foo', 'bar')  // foo-bar, cached

const m3 = memoize(
  [WeakMap, Map, WeakMap], 
  (v1, v2, v3) => `${JSON.stringify(v1)}-${JSON.stringify(v1)}-${JSON.stringify(v3)}`
)
let v1 = {}, v2 = 'foo', v3 = {}
m3(v1, v2, v3)  // {}-"foo"-{} uncached
m3(v1, v2, v3)  // {}-"foo"-{} cached

memoize(caches <Array>, fn <Function>)

• caches <Array>
  • An array of plain objects or constructors used for caching each level of the tree. The first array element will be the cache for the first argument of the function, call, and so on. Therefore, the length of this array must be the same as the length of arguments your memoized function accepts.
  • You may provide your own cache (i.e. not Map, WeakMap, {}). The only requirement is that it has get and set methods.
• fn <Function>
  • The function being memoized