I recently learned that it’s possible to delegate common implementations of protocols using defdelegate in the implementations, but I’m curious to know if this is possible using a macro that provides overridable functions. The following code works, but shows a warning (see comment below) : defprot…

I’m not sure I agree with this approach to begin with, but if you were to go this way I think it makes more sense to do a __using__ instead of a before compile. The the function is injected at the top, and you override it in your defimpl block. As it is it’s always at the bottom, which is likely wha…

@benwilson512 [image] benwilson512: I’m not sure I agree with this approach to begin with What’s the idiomatic way to do this? [image] benwilson512: I think it makes more sense to do a using instead of a before compile Yes, this works. So I guess the problem with before_compile here …

[image] emilsoman: What’s the idiomatic way to do this? You can explicitly delegate to the function you want to: defimpl MyProtocol, for: Integer do def foo(data) do MyProtocol.Default.foo(data) end ... end You can even use defdelegate to make it more compact: defimpl MyProtocol…

Can a case be made to have default implementations be delegated to Any when its implementation is missing? defprotocol Duration do @fallback_to_any true def seconds(a) def compare(a, b) end defimpl Duration for: Any do def seconds(_), do: raise "Not yet implemented" def compare(_…

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Overridable functions in protocol implementations?

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benwilson512 September 21, 2016, 12:03pm 5

My thoughts precisely.