Count items and compare them against a reference
Simply install it via NPM (npm install countjs) and require it
in your code:
var Counter = require('countjs')
var c = new Counter()countjs is relatively simple -- just instantiate a counter and keep
adding stuff to it:
var c = new Counter()
c.add('a')
c.add('a')
c.add('b')Then you can get how many items are there in the counter:
c.get('a') // 2
c.get('b') // 1
c.get() // {a: 2, b: 1}You can also specify a custom quantity to add:
c.add('a', {qty: 3}) // 2
c.get('a') // 3And create a diff between counters:
var c1 = new Counter({a: 1})
var c2 = new Counter({b: 1})
c1.diff(c2)
// {
// a: {
// mine: 1,
// other: 0,
// diff: 1
// },
// b: {
// mine: 0,
// other: 1,
// diff: -1
// }
// }
var c3 = new Counter({a: 1, b: 1})
c3.diff(c2)
// {
// a: {
// mine: 1,
// other: 0,
// diff: 1
// }
// }You can also use "references": if an item has qty X
in the reference, then your counter will not be able to
add more than X qty of that item:
var ref = {a: 1, b: 2}
var c = new Counter({}, ref)
c.add('a') // true
c.add('a') // false
c.add('b', {qty: 3}) // false
c.add('b', {qty: 2}) // true
c.add('c') // false
c.get() // {a: 1, b: 2}You can force the counter to accept the new value:
var ref = {a: 1}
var c = new Counter({}, ref)
c.add('a') // true
c.add('a') // false
c.add('a', {qty: 1, force: true}) // true
c.get() // {a: 2}When using references, you can get a diff between the current counter and the reference. For example:
var ref = {a: 1}
var c = new Counter({}, ref)
c.add('a', {qty: 2, force: true}) // true
c.add('b', {qty: 3, force: true}) // true
c.diff() // {a: {mine: 2, other: 1, diff: 1}, b: {mine: 3, other: 0, diff: 3}}Last but not least, you can get a full comparison between counters:
var c1 = new Counter({a: 1, b: 1, d: 3})
var c2 = new Counter({b: 2, c: 1, d: 3})
comparison = c1.compare(c2)
// {
// a: mine 1, other 0
// b: mine 1, other 2
// c: mine 0, other 1
// d: mine 3, other 3
// }compare is, basically, a #diff() that also includes same values
between counters.
Just run npm test and welcome to Greenland!
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