Programming Erlang, 2nd Edition

Attributes

Module attributes have the syntax -AtomTag(...) and are used to define certain properties of a file. (Note: -record(...) and -include(...) have a similar syntax but are not considered module attributes.) There are two types of module attributes: predefined and user-defined.

Predefined Module Attributes

The following module attributes have predefined meanings and must be placed before any function definitions:

-module(modname).

The module declaration. modname must be an atom. This attribute must be the first attribute in the file. Conventionally the code for modname should be stored in a file called modname.erl. If you do not do this, then automatic code loading will not work correctly; see ​Dynamic Code Loading​ for more details.