Programming Elixir 1.3

Compiling a Module

Let’s look at two ways to compile this file and load it into iex. First, if you’re at the command line, you can do this:

$ iex times.exs
iex> Times.double(4)
8

Give iex a source file’s name, and it compiles and loads the file before it displays a prompt.

If you’re already in iex, you can use the c helper to compile your file without returning to the command line.

iex> c "times.exs"
[Times]
iex> Times.double(4)
8
iex> Times.double(123)
246

The line c "times.exs" compiles your source file and loads it into iex. We then call the double function in the Times module a couple of times using Times.double.

What happens if we make our function fail by passing it a string rather than a number?

iex> Times.double( ...