"Elixir Sips" is a nice little screencast site showcasing and howto-ing various Elixir features. They have an episode on Dialyzer:

http://elixirsips.com/episodes/125_dialyzer.html

Elixir has first-class support for defining custom types and adding type annotations (specs) to functions. There's also a tool that makes it very easy to run dialyzer on your code: https://github.com/fishcakez/dialyze

yes