Doing import.bar in the user dfined code side seems to solve the problem.
I expected that exporting bar out of the module would also solve the
problem, however, it doesn't.
On Saturday, July 26, 2014 10:01:50 PM UTC+1, Abe Schneider wrote:
>
> I have a pattern that has come up multiple times where in a module I might
> have some function `foo` which will call some other function `bar` on a
> given type. The exact function `bar` isn't defined yet because it is
> defined by the user-type. The problem I run into is that if `bar` is
> defined outside of the module, `foo` won't see it.
>
> Here is a simple example:
> module testmod
>
> export foo, Baz
>
> abstract Baz
>
> bar(x::Baz) = nothing
>
> function foo(x::Baz)
> return bar(x)
> end
>
> end
>
> with the user-defined code:
> using testmod
>
> type ConcreteBaz <: Baz
> value::Int64
> end
>
> function bar(baz::ConcreteBaz)
> return baz.value
> end
>
> baz = ConcreteBaz(42)
> println("result = $(foo(baz))")
>
> The output is `result = nothing`, and thus the wrong function is called.
> If I move all of the code to the same file it works.
>
> My question is: is this expected behavior? If so, what's the proper way of
> creating an interface for an abstract type which can later be overridden in
> a user file?
>
