Erlang: module attribute

2019-04-06 18:37发布

问题:

I am new to Erlang. Found the following -module attribute declaration in an existing Erlang project:

-module(mod_name, [Name, Path, Version]).

What does mean the second parameter (list [Name, Path, Version]) here?

I haven't found any information in the Erlang reference on it.

回答1:

This defines a parameterised erlang module - one you can "instantiate" with new and then access the parameters passed by that new when executing code in your module.

A very brief overview is here:

http://myotherpants.com/2009/04/parameterized-modules-in-erlang/



回答2:

This is a parametrized module. Here is the original paper on it. Basically you can create instances of the module binding specific values to those variables. You can initialize one as:

> Mod = mod_name:new("MyName", "/path", '0.1').

and then call its functions as:

> Mod:function(...)

where the module parameters are also available in the function body.



标签: erlang module