With the elixir-lang 1.0.0 release approaching, I thought I’d jump in and get better acquainted with the language. First, a huge thanks to Jose and everyone involved with elixir. As much for creating a great new language, but also for giving me more motivation to read my Programming Erlang book.

Here are a few first things in learning the language…

Interactive Elixir: iex

Having an interactive mode is incredible. I’ve so use to irb (interactive ruby) for so long, I was thrilled to see this available for elixir.

The first struggle was trying to quit iex. I was so used to ctrl-d working, I was quite surprised when it didn’t work. Instead, to quit iex it’s ctrl-g q <enter>. I’m guessing there’s more to that than meets the eye.

help within iex

This is awesome, the language documentation is available within iex.

iex(10)> h is_boolean/1

    def is_boolean(term)

  Returns true if term is either the atom true or the atom false (i.e. a
  boolean); otherwise returns false.

  Allowed in guard tests. Inlined by the compiler.

The h is_boolean/1 means: ‘help on function is_boolean with arity 1.

The help has tab completion too…

    iex(27)> h is_<tab>
    is_atom/1         is_binary/1       is_bitstring/1    is_boolean/1
    is_float/1        is_function/1     is_function/2     is_integer/1
    is_list/1         is_map/1          is_number/1       is_pid/1
    is_port/1         is_reference/1    is_tuple/1
    iex(27)> h is_<cursor>

The arity isn’t required for getting help. And, when not given for something that has multiple signatures (or whatever elixir calls them), will show all matches. E.g., h is_function will display help for both the arity 1 and arity 2 versions.

Still Learning

I’m just getting started, but it’s fun to learn a language that gives you approachable tools, like iex, to play with. Next up is to figure out why this works, and why I should know why it works…

iex(43)> [1, 2, 3] |> Enum.map(&(&1 * &1))
[1, 4, 9]
iex(44)>

Check out Elixir. If you want high level information, check out the Elixir Conf videos.