If you’re looking for a library to use in your app, you’ll want to look first for existing Elixir modules. The built-in ones are documented on the Elixir website,[11] and others are listed at http://hex.pm and on GitHub (search for elixir).
If that fails, search for a built-in Erlang library or search the web.[12] If you find something written in Erlang, you’ll be able to use it in your project (we’ll cover how in the chapter on projects,). But be aware that the Erlang documentation for a library follows Erlang conventions. Variables start with uppercase letters, and identifiers that start with a lowercase letter are atoms (so Erlang would say tomato and Elixir would say :tomato). A summary of the differences between Elixir and Erlang is available online.[13]
Now that we’ve looked at functions, let’s move on to the data they manipulate. And where better to start than with lists? They’re the subject of the next chapter.