map-memo

Generic memoization with Map and WeakMap

Showing:

Popularity

Downloads/wk

7

GitHub Stars

8

Maintenance

Last Commit

2yrs ago

Contributors

2

Package

Dependencies

0

Size (min+gzip)

0.4KB

License

MIT

Type Definitions

Tree-Shakeable

No?

Categories

Deprecated!
This package has moved to @starryinternet/map-memo

Readme

map-memo

Build Status

Generic memoization using Map and WeakMap.


Installing

npm install --save @starryinternet/map-memo

What/Why?

Memoization in JavaScript has typically been limited to arguments with primitive values, or by utilizing hacks such as stringifying objects.

By storing arguments using a series of nested cache objects backed by Map and WeakMap, map-memo is able to memoize functions with any argument types.


Example

'use strict';

const memoize = require('@starryinternet/map-memo');

function loop( fn, n ) {
  let v;

  for ( let i = 0; i < n; ++i ) {
    v = fn( i );
  }

  return v;
}

let mem = memoize( loop );

console.log( mem( Math.sqrt, 1e9 ) ); // slow
console.log( mem( Math.sqrt, 1e9 ) ); // fast!

Example with expire time in milliseconds

'use strict';

const memoize = require('@starryinternet/map-memo');

function getRandom() {
  return Math.random();
}

let mem = memoize( getRandom, { ttl: 1000 } );
console.log( mem() );
console.log( mem() ); // Same value as above

setTimeout( function() {
  console.log( mem() ); // Different value
}, 1001 );

Example with asynchronous function

'use strict';

const memoize = require('@starryinternet/map-memo');

function loopAsync( fn, n ) {
  return new Promise( ( resolve, reject ) => {
    let v;

    for ( let i = 0; i < n; ++i ) {
      v = fn( i );
    }

    resolve( v );
  });
}

let mem = memoize( loopAsync );

mem( Math.sqrt, 1e9 ).then( result => {
  console.log( result ); // slow
  mem( Math.sqrt, 1e9 ).then( console.log ); // fast!
});

Rate & Review

Great Documentation0
Easy to Use0
Performant0
Highly Customizable0
Bleeding Edge0
Responsive Maintainers0
Poor Documentation0
Hard to Use0
Slow0
Buggy0
Abandoned0
Unwelcoming Community0
100