We need to add role annotations for 7.8

Andres Löh andres at well-typed.com
Thu Mar 13 21:56:49 UTC 2014

Hi there.

Please forgive my ignorance w.r.t. roles, but why aren't all of these

> 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?

Thanks in advance for explaining.


Andres Löh, Haskell Consultant
Well-Typed LLP, http://www.well-typed.com

More information about the Libraries mailing list