Fast Map extension for Node.js & The Browser
LightMap is an extension of Map that adds iterative extensions to Map like map, filter, reduce, sort, etc.
npm i @mi-sec/lightmap
Basic usage:
const LightMap = require( '@mi-sec/lightmap' ); const x = new LightMap( [ [ 'a', 'hello' ], [ 'b', 'world' ] ] ); // LightMap{'a' => 'hello', 'b' => 'world' } Map usage:
For standard Map usage please refer to MDN Web Docs
.filter:
Filter LightMap based on keys and values based in. Comparisons can be made on the key and/or value.
const x = new LightMap( [ [ 'a', 'hello' ], [ 'b', 'world' ] ] ); x.filter( ( val, key ) =>{return key === 'a'} ); // LightMap{'a' => 'hello' } .map:
Map LightMap with new key and/or value. Return the new item in a "tuple" form matching the Map paradigm ([ x, y ]).
const x = new LightMap( [ [ 'a', 10 ], [ 'b', 20 ] ] ); x.map( ( val, key ) =>{return [ key, val + 10 ]} ); // LightMap{'a' => 20, 'b' => 30 } .reduce:
Reduce LightMap with new value. Must return the carriage value just like Array.reduce.
const x = new LightMap( [ [ 'a', 'hello' ], [ 'b', 'world' ] ] ); x.reduce( ( r, [ key, val ] ) =>{r += val + ' '; return r}, '' ); // hello world .sortKeys:
Map LightMap with sorted key-value pairs.
const x = new LightMap( [ [ 'b', 'world' ], [ 'a', 'hello' ] ] ); x.sortKeys() // LightMap{'a' => 'hello', 'b' => 'world' } .sortValues:
Map LightMap with sorted key-value pairs sorted by value.
const x = new LightMap( [ [ 'a', 10 ], [ 'b', 5 ], [ 'c', 1 ] ] ); x.sortValues( ( a, b ) => a >= b ) // LightMap{'c' => 1, 'b' => 5, 'a' => 10 } x.sortValues( ( a, b ) => a <= b ) // LightMap{'a' => 10, 'b' => 5, 'c' => 1 } .mapToArray:
maps a LightMap object to an array of arrays in the Map Pattern (re-constructable pattern)
const x = new LightMap( [ [ 'a', 0 ], [ 'b', 1 ] ] ); x.mapToArray(); // [ [ 'a', 0 ], [ 'b', 1 ] ] .toJSON:
Native class override - returns .mapToArray method
const x = new LightMap( [ [ 'a', 0 ], [ 'b', 1 ] ] ); x.toJSON(); // [ [ 'a', 0 ], [ 'b', 1 ] ] .toString:
Native class override - returns JSON stringified .mapToArray
const x = new LightMap( [ [ 'a', 0 ], [ 'b', 1 ] ] ); x.toString(); // [["a",0],["b",1]] .indexOf:
returns the first index at which a given element can be found in the array, or -1 if it is not present
const x = new LightMap( [ [ 'a', 0 ], [ 'b', 1 ] ] ); x.indexOf( 'b' ); // 1 [ Symbol.replace ]:
symbol specifies the method that replaces matched substrings of a string
const x = new LightMap( [ [ '{{a }}', 'hello' ], [ '{{b }}', 'world' ] ] ); '{{a }}{{b }}'.replace( x ); // hello world [ Symbol.toPrimitive( string ) ]:
symbol that specifies a function valued property that is called to convert an object to a primitive value
const x = new LightMap( [ [ 'a', 0 ], [ 'b', 1 ] ] ); '' + x; // [["a",0],["b",1]] [ Symbol.toPrimitive( number ) ]:
symbol that specifies a function valued property that is called to convert an object to a primitive value
const x = new LightMap( [ [ 'a', 0 ], [ 'b', 1 ] ] ); +x; // 2 (size of the Map)