Modules in Elixir may contain attributes. They're normally used where you'd use constants in other languages. You define a module attribute with the following syntax:
$ cat examples/string_helper_with_module_attribute.exdefmodule StringHelper do @default_mark "!" # rest of the StringHelper codeend
Then, we can use the @default_mark module attribute inside the functions of this module. This attribute only exists at compile time, as it's replaced by its value during this process.
There are some other use cases for module attributes: you can register them, which makes them accessible at runtime. For instance, Elixir registers the @moduledoc and @doc attributes, which can be used to provide documentation ...
