JSPM – @thi.ng/memoize@2.0.11

Package Exports

@thi.ng/memoize
@thi.ng/memoize/memoizej

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (@thi.ng/memoize) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

npm downloads

This project is part of the @thi.ng/umbrella monorepo.

About
- Status
Installation
Dependencies
Usage examples
API
Authors
License

About

Function memoization with configurable caching.

This package provides different function memoization implementations for functions with 1 or more arguments and custom result caching using ES6 Map API like implementations. Unlike native ES6 Maps, the implementations MUST support value, not just referential, equality semantics (e.g. those provided by @thi.ng/associative) or @thi.ng/cache). The latter also support automatically pruning of memoization caches, based on different strategies. See doc strings for further details.

Status

STABLE - used in production

Installation

yarn add @thi.ng/memoize

// ES module
<script type="module" src="https://unpkg.com/@thi.ng/memoize?module" crossorigin></script>

// UMD
<script src="https://unpkg.com/@thi.ng/memoize/lib/index.umd.js" crossorigin></script>

Package sizes (gzipped, pre-treeshake): ESM: 254 bytes / CJS: 305 bytes / UMD: 376 bytes

Dependencies

Usage examples

Several demos in this repo's /examples directory are using this package.

A selection:

Screenshot	Description	Live demo	Source
	Basic rstream-gestures multi-touch demo	Demo	Source
	rstream based spreadsheet w/ S-expression formula DSL	Demo	Source

API

Generated API docs

import * as m from "@thi.ng/memoize";

// (optional, for custom caching)
import { EquivMap } from "@thi.ng/associative";
import { LRUCache } from "@thi.ng/cache";

Optimized version for single arg functions

foo = m.memoize1((x) => (console.log("exec"), x * 10));
foo(1);
// exec
// 10
foo(1);
// 10

// with custom cache
foo = m.memoize1(
    (x) => (console.log("exec"), x[0] * 10),
    new EquivMap()
);

foo([1]);
// exec
// 10
foo([1]); // wouldn't work w/ native ES6 Map as cache
// 10

// use LRU cache to limit cache size
foo = m.memoize1(
    (x) => (console.log("exec"), x[0] * 10),
    new LRUCache(null, { maxlen: 3 })
);

Arbitrary args

dotProduct = m.memoize(
    (x, y) => (console.log("exec"), x[0] * y[0] + x[1] * y[1]),
    new EquivMap()
);

dotProduct([1,2], [3,4]);
// exec
// 11
dotProduct([1,2], [3,4]);
// 11

Via JSON.stringify()

dotProduct = m.memoizeJ(
    (x, y) => (console.log("exec"), x[0] * y[0] + x[1] * y[1])
);
dotProduct([1,2], [3,4]);
// exec
// 11
dotProduct([1,2], [3,4]);
// 11

Authors

Karsten Schmidt

@thi.ng/memoize