Merge pull request #614 from Chalarangelo/nest

Create nest

snippets/nest.md

@@ -0,0 +1,29 @@
+### nest
+
+Given a flat array of objects linked to one another, it will nest them recursively.
+Useful for nesting comments, such as the ones on reddit.com.
+
+Use recursion. Use `Array.filter()` to filter the items where the `id` matches the `link`,
+then use `Array.map()` to map each one to a new object that has a `children` property which
+recursively nests the items based on which ones are children of the current item. Omit the second 
+argument, `id`, to default to `null` which indicates the object is not linked to another one (i.e.,
+it is a top level). Omit the third argument, `link`, to use `'parent_id'` as the default property
+which links the object to another one by its `id`.
+
+```js
+const nest = (items, id = null, link = 'parent_id') =>
+  items.filter(item => item[link] === id).map(item => ({ ...item, children: nest(items, item.id) }))
+```
+
+```js
+// One top level comment
+const comments = [
+  { id: 1, parent_id: null },
+  { id: 2, parent_id: 1 },
+  { id: 3, parent_id: 1 },
+  { id: 4, parent_id: 2 },
+  { id: 5, parent_id: 4 }
+]
+const nestedComments = nest(comments) // [{ id: 1, parent_id: null, children: [...] }]
+```
+

tag_database

@@ -162,6 +162,7 @@ minBy:math,array,function
 minN:array,math
 mostPerformant:utility,function
 negate:function
+nest:object
 none:array,function
 nthArg:utility,function
 nthElement:array