@thi.ng/memoize

[!NOTE] This is one of 190 standalone projects, maintained as part of the @thi.ng/umbrella monorepo and anti-framework.

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• About
• Status
• Related packages
• Installation
• Dependencies
• Usage examples
• API
  • Optimized version for single arg functions
  • Arbitrary args
  • Via JSON.stringify()
• 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

Search or submit any issues for this package

Related packages

• @thi.ng/cache - In-memory cache implementations with ES6 Map-like API and different eviction strategies

Installation

yarn add @thi.ng/memoize

ES module import:

<script type="module" src="https://cdn.skypack.dev/@thi.ng/memoize"></script>

Skypack documentation

For Node.js REPL:

const memoize = await import("@thi.ng/memoize");

Package sizes (brotli'd, pre-treeshake): ESM: 247 bytes

Dependencies

• @thi.ng/api

Usage examples

Several projects in this repo's /examples directory are using this package:

Screenshot	Description	Live demo	Source
	Isolated, component-local DOM updates	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

import { memoize1 } from "@thi.ng/memoize";

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

foo(1);
// exec
// 10
foo(1);
// 10

import { EquivMap } from "@thi.ng/associative";

// with custom cache
foo = memoize1(
    (x) => (console.log("exec"), x[0] * 10),
    // custom ES6 Map impl which compares by value, not by reference
    new EquivMap()
);

foo([1]);
// exec
// 10

// would be a cache miss w/ native ES6 Map
foo([1]);
// 10

import { LRUCache } from "@thi.ng/cache";

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

Arbitrary args

import { memoize } from "@thi.ng/memoize";
import { EquivMap } from "@thi.ng/associative";

const dotProduct = 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()

import { memoizeJ } from "@thi.ng/memoize";

const dotProduct = 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

If this project contributes to an academic publication, please cite it as:

@misc{thing-memoize,
  title = "@thi.ng/memoize",
  author = "Karsten Schmidt",
  note = "https://thi.ng/memoize",
  year = 2018
}

License

© 2018 - 2024 Karsten Schmidt // Apache License 2.0