venn


Motivation

One of these days I was looking for a library that would allow me to do simple set operations, mostly intersection and union. There's a lot of libraries that do this but I didn't find one with a fluent API. This a stab at one:

Compatible with AMD and node.

$3

A venn set is just an array on steroids:

``javascript

var venn = require("venn")
venn.create([1,2])
console.log(venn) // [1,2]

`

$3

You can now chain operations to this set, using union or or:

`javascript
venn.create([1,2])
.union([1,2,3,4])
.or([5]) // [1,2,3,4,5]
`

union and or are just alias for the same operation.

$3


`javascript
venn.create([1,2])
.union([1,2,3,4])
.intersection([1,5]) // [1]
`

if you prefer you can also use and instead of intersection




$3

If you want to be negative about it, you can check out not

`javascript
venn.create([1,2,3,4,5])
.not([4])
.not([5]) // [1,2,3]
`

$3

Or a mix of everything

`javascript
venn.create([1,2])
.or([1,2,3,4,5])
.and([1,5])
.or([2]) // [1,5,2]
`

$3

If you're crazy you can use venn without a key function. We'll just figure it out how to index the objects.

`javascript
venn.create([
{name: "vitor", age: "23"}
, {name: "khov", age: "24"}
, {name: "pat", age: "30"}])
.intersection([
{name: "vitor", age: "23"}
, {name: "newguy", age: "0"}
, {name: "pat", age: "50"}])
.union([
{name: "khov", age : "10"}
, {name: "nuno", age : "20"}])

// vitor, khov and nuno
`

$3

But really, write your own key function:

`javascript

var myKeyFunction = function(item) {
return item.name
}

venn.create([
{name: "vitor", age: "100"}
, {name: "khov", age: "100"}], myKeyFunction)
.and([
{name: "vitor", age: "0"}
, {name: "khov", age: "0"}
.or([
{name: "khov", age : "-100"}
, {name: "nuno", age : "20"}])

// vitor, khov(the first of them), nuno
`

$3

* The keyFunction only needs to be set once for each venn object (as you would expect)
* Don't forget if you apply a built-in array function like filter or map` the returning object is not a venn object (as you would once again expect)

Let me know if there are improvements I can do to the library. I might take some time to implement the other less used set operations.