Hot code replacement in erlang

Question

I am working on my first real project in erlang, however, this code is simplified for brevity. I want to be able to load a newer version of a file into my project r

Answer 1

For the sake of having an explicit answer, I am posting this.

Using @rvirding's suggestion of using the code module, I've modified it to look like this:

-module(reloading).

-export([loop/0]).

loop() ->
    receive
        upgrade ->
            code:purge(?MODULE),
            compile:file(?MODULE),
            code:load_file(?MODULE),
            ?MODULE:loop();
        hello ->
            io:format("This is a test~n"),
            loop();
        _ ->
            loop()
    end.

First code:purge the old ?MODULE, then compile:file the new file, and finally, code:load_file the new ?MODULE. This works as I originally intended.

$ erl
Erlang R15B01 (erts-5.9.1) [source] [64-bit] [async-threads:0] [hipe] [kernel-poll:false]

Eshell V5.9.1  (abort with ^G)
1> Loop = spawn(reloading, loop, []).
<0.34.0>
2> Loop ! hello.
This is a test
hello

Change line to io:format("I have changed this!~n"),

3> Loop ! upgrade.                   
upgrade
4> Loop ! hello.  
I have changed this!
hello