Is it possible to document modules defined at runtime?

Questions / Help
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1

I am defining a module at runtime with Module.create/3. I am looking for a way to document the module and functions in the module so that the documentation can be retrieved for example in iex with the h function.

Simply adding @doc "my nice documentation" in the quoted expression passed to Module.create/3 does not do the trick, h my_function in iex returns " was not compiled with docs".

Is there a way to document a module created at runtime?

2

There‘s not. Documentation is read from the beam files of compiled modules. Runtime defined modules do not have corresponding beam files.

3

Would it be possible to write the module to a beam file at runtime?

4

I also wondered if it is possible to write doc chunks explicitly to doc/chunks/<my_module>.chunk so solve the problem. If I understand [Eep 0048 - Erlang/OTP](https://EEP 48: Documentation storage and format) correctly this should be picked up if there is no documentation in the beam file. But I did not find anything on producing these doc chunks from Elixir. Does anyone know more about this?

5

I’d expect that an external chunk file is allowed for third party tooling to also be able to supply documentation. This is still not a great solution for in memory modules given it would also need cleaning up.

6

If I am redefining a pre-existing module (i.e. a module with a compiled beam file) the documentation of that compiled file is shown for the re-defined module. This way it is possible to provide “default” documentation. Feels pretty hacky though.