Add Reversing A List as an elixir til

README.md

@@ -7,7 +7,7 @@ variety of languages and technologies. These are things that don't really
 warrant a full blog post. These are mostly things I learn by pairing with
 smart people at [Hashrocket](http://hashrocket.com/).
 
-_448 TILs and counting..._
+_449 TILs and counting..._
 
 ---
 
@@ -91,6 +91,7 @@ _448 TILs and counting..._
 - [Pattern Matching In Anonymous Functions](elixir/pattern-matching-in-anonymous-functions.md)
 - [Quitting IEx](elixir/quitting-iex.md)
 - [Replace Duplicates In A Keyword List](elixir/replace-duplicates-in-a-keyword-list.md)
+- [Reversing A List](elixir/reversing-a-list.md)
 - [String Interpolation With Just About Anything](elixir/string-interpolation-with-just-about-anything.md)
 - [Word Lists For Atoms](elixir/word-lists-for-atoms.md)
 

elixir/reversing-a-list.md

@@ -0,0 +1,19 @@
+# Reversing A List
+
+To efficiently work with and _transform_ lists in Elixir, you will likely
+need utilize a list reversing function from time to time. Your best bet is
+to reach for the Erlang implementation which is available as part of the
+`lists` module.
+
+Here are a couple examples of how to use it:
+
+```elixir
+> :lists.reverse([1,2,3])
+[3, 2, 1]
+> :lists.reverse([1, :a, true, "what", 5])
+[5, "what", true, :a, 1]
+```
+
+Note: though I said "_transform_ lists" above, what is actually going on is
+that a new version of the list representing my transformation is being
+created, per Elixir's functional nature.