node-lazy-range

Lazy Range function for JS. Exposes forEach forEachAsync and toArray

1npm install lazy-range

Example.js

1var range = require('./range')
2
3/*
4  Faster than Array.map since it does
5  array composition and function application in same step
6*/
7var arr = range(1,11).map(function(i) {
8    return i*5
9})
10
11// You can also use a step param
12
13range(0,10,2).toArray(); // where step == 2
14//[0, 2, 4, 6, 8]
15
16
17console.log(arr)
18
19/*
20You can still do
21*/
22arr = range(1,11).toArray().map(function(i) {
23    return i*2
24})
25console.log(arr)
26
27
28/*
29As well we can just execute a function against a range but not return an array
30*/
31range(1,11).forEach(function(i) {
32    console.log(Math.exp(i,2))
33})
34
35/*
36As well we can execute Async
37*/
38range(1,11).forEachAsync(function(i) {
39    console.log('num:' + Math.exp(i,2));
40})
41console.log('This should come first')

Results: (example.js)

1[ 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 ]
2[ 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 ]
32.718281828459045
47.38905609893065
520.085536923187668
654.598150033144236
7148.4131591025766
8403.4287934927351
91096.6331584284585
102980.9579870417283
118103.083927575384
1222026.465794806718
13This should come first
14num:2.718281828459045
15num:7.38905609893065
16num:20.085536923187668
17num:54.598150033144236
18num:148.4131591025766
19num:403.4287934927351
20num:1096.6331584284585
21num:2980.9579870417283
22num:8103.083927575384
23num:22026.465794806718
24