Overriding non-defoverridable functions generated by use macro?

Questions / Help
,
1

Is there any way to override functions generated by a use macro when those functions have NOT been tagged as defoverridable?

I’m tapped into a 3rd party package which does mostly what we want, but we need to do some tweaking of the return values to make things work with our particular stack.

The easiest solution is of course to define our own variant of the function under a different name, e.g.

defmodule OurModule do
  use Something

  def something_alternate(opts \\ []) do
        # custom stuff
        something(opts)
  end
end

But it’s a bummer to not be able to avail ourselves of the nice interface in the 3rd party package, so I was wondering if it would be possible to somehow override the functions that it generates.

For example, maybe we could roll our own defoverridable via something like this?

defmodule Wrapper do
  defmacro __using__(opts) do
    quote do
      use Something

      defoverridable Module.definitions_in(__MODULE__)
  end
end

Curious if anyone has tried this or can offer words of wisdom before I try this out in the laboratory…

2

You can, and you don’t even need to wrap it in your own use. You can just put the defoverridable inline in the module where you need that.

1 Like
3

Not sure I follow that – where exactly? If I do this:

defmodule OurModule do
  use Something
  defoverrideable something: 1

  def something(opts \\ []) do
        # custom stuff here
  end
end

It gets a compilation warning:

warning: this clause for something/1 cannot match because a previous clause at line 5 always matches
  path/to/file
1 Like
4

Should be defoverridable

5

Hahaaa … thankyou. Another case where the problem was between the keyboard and the chair.