JavaScript Array Extension
A small library with array generic operations.
WARNING!!!! The npm scope of this package was removed from his name.
Please do not install this package anymore, instead go to https://www.npmjs.com/package/js-array-ext.
Installation
Installation becomes:
npm install js-array-ext
Philosophy under the hood
I think that most of the time what algorithm's programer does is iterate in different ways over one or many list of element and for each iteration applying a process. Some of those iteration are simply join, intersection, etc, in the other occasions could be no so easy to see which is the generic iteration/operation we need.
In this small library I try to do basically four things:
- Add basic
Array
's iterations. - Add basic operation over Sorted Arrays with unduplicated values, I call those type of arrays as
srtf
(Sorted and Filtered). - Add complex
Array
's iterations. - Add complex iterations over
srtf
Array
s.
All the functions in this library are built base on current JS Array methods (see https://www.w3schools.com/jsref/jsref_obj_array.asp) as much as possible or in function defined in this library.
Installation
npm install js-array-ext
npm install js-array-ext
API
Usage
var idtArray = require('@ideastouch/js-array-ext');
var srt = [0, 1, 2, 3, 4, 5];
var compareNumber = (num1, num2) => num1 - num2;
var srtSliceFind = idtArray.sliceFind(srt, 3, compareNumber);
Output should be [3, 4, 5]
Comparisons
Before
var xCoords = [3, 4, 6, 8];
var yCoords = [1, 5, 2, 4];
var points = [];
xCoords.forEach(x => {
yCoords.forEach(y, => {
points.push({x, y});
})
});
After
var idtArray = require('@ideastouch/js-array-ext');
var xCoords = [3, 4, 6, 8];
var yCoords = [1, 5, 2, 4];
var points = idtArray.combine(xCoords, yCoords, (x, y) => ({x, y}));
// BTW: If we want a new list of sorted points base on point distance
// to origin (0, 0) we can just do:
var DD = p => p.x * p.x + p.y * p.y; // DD is for Delta * Delta.
var DDCompare = (p1, p2) => DD(p1) - DD(p2);
var srtPnts = idtArray.sort(points, DDCompare);
Tests
npm test
Future Functions
splitFilter(array, processFunction)
Split array
in tree Array
, one for elements in which processFunction
return negative number, one for case return cero and one for case return positive numbers.
reduceMap(array, processFunction, reduceFunction, initial)
Call to processFunction
for each element and and push each result in an Array. Then call to reduceFunction
in same way as Array.reduce
. Default for initial
is an empty Array
and default for reduceFunction
is Array.concat
Contributing
So far only my self.