Merge pull request #512 from Chalarangelo/partition

[FEATURE] Add partition

snippets/partition.md

@@ -0,0 +1,19 @@
+### partition
+
+Groups the elements into two arrays, depending on the provided function's truthiness for each element.
+
+Use `Array.reduce()` to create an array of two arrays.
+Use `Array.push()` to add elements for which `fn` returns `true` to the first array and elements for which `fn` returns `false` to the second one.
+
+```js
+const partition = (arr, fn) =>
+  arr.reduce((acc, val, i, arr) => {acc[fn(val,i,arr) ? 0 :1].push(val); return acc;},[[],[]]);
+```
+
+```js
+var users = [
+  { 'user': 'barney',  'age': 36, 'active': false },
+  { 'user': 'fred',    'age': 40, 'active': true }
+];
+partition(users, o => o.active) // [[{ 'user': 'fred',    'age': 40, 'active': true }],[{ 'user': 'barney',  'age': 36, 'active': false }]]
+```

tag_database

@@ -111,6 +111,7 @@ once:function
 onUserInputChange:browser,event,advanced
 orderBy:object,array
 palindrome:string
+partition:array,object,function
 percentile:math
 pick:array
 pipeFunctions:adapter,function