malias - module alias

To prevent name collision, every Erlang library uses some prefix for each module(e.g.: cowboy_, ejabberd_, rabbit_). But standard Erlang doesn't provide means for aliasing such long names to more readable and short forms.

malias is a parse-transform library, which allows to use any module with another(more terse) name.

Here is a short example of using Cowboy library:

-module(index_handler).
-behaviour(cowboy_http_handler).

-compile({parse_transform, malias}).
-malias([{cowboy_req, req}]).

handle(Req, State) ->
    Body = <<"<h1>It works!</h1>">>,
    {ok, Req2} = req:reply(200, [], Body, Req),
    {ok, Req2, State}.

Here cowboy_req module is aliased to req name inside of index_handler module.

Usage

Add malias as first dependency in rebar.config:

%% add malias in dependencies
{deps, [
  {malias, ".*", {git, "https://github.com/cris/malias.git", {branch,"master"}}}
]}.

Being first is crucial, because parse-transform module should be built before usage in project.

Now add parse_transform compile option in each module, where malias will be used:

-compile({parse_transform, malias}).

Then add malias substitution option. It's a simple proplist with {original_name, aliased_name} pairs:

-malias([{lists, l}, {string, s}, {myproject_handler, handler}]).

For one substitution, bare tuple can be used:

-malias({lists, l}).

Implementation details and support

Right now malias correctly handle substitution in module function call:

A = short_name:fun()

or wrapping module function into lambda:

F = fun short_name:fun/0

malias is tested on Erlang R16, and should correctly work on R15 and R17(with maps support).

In case of any issues fill in a bug or do a pull-request.