We need to add role annotations for 7.8

Andres Löh andres at well-typed.com
Thu Mar 13 22:00:14 UTC 2014

[Sorry for the self-reply.]

Oh, perhaps I actually understand this:

> Please forgive my ignorance w.r.t. roles, but why aren't all of these
> representational?
>> Map k v -- k: nominal, v: represententional
>> Set a -- k: nominal
> AFAIK both Map and Set are "normal" datatypes. Not GADTs, no type
> families involved. Why would anything need to be "nominal" then?

Is this because the integrity of these types relies on the Ord
instance being sane, and a newtype could have a different Ord instance


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