Using associated data types to create unpacked data structures

Simon Marlow marlowsd at
Thu Aug 12 07:38:30 EDT 2010

On 12/08/2010 12:28, Johan Tibell wrote:

>         This doesn't quite work though as two MapIntDouble defined in two
>         different libraries are incompatible. This is essentially the same
>         problem as with instance collisions.
>     But you get to choose the module name, so you can avoid collisions
>     by using qualified names.
> Sorry, I was being unclear. The problem is that library A can't pass a
> MapIntDouble to library B as the types defined by the two libraries
> aren't compatible.

That's true, but is it really going to cause many problems in practice? 
  Which libraries have functions that take a Map argument, other than 
the Map library itself?


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