16 Sep
2014
16 Sep
'14
12:58 a.m.
* Richard Eisenberg <eir@cis.upenn.edu> [2014-09-15 08:56:05-0400]
Have you tried using closed type families with the type-level (==) operator from GHC 7.8's Data.Type.Equality? That's how I've done unions before. The key step is to use a closed type family to write a type family equation that triggers when two types do *not* equal.
Let me know if you need more info... Thanks. I will take a look for my education, but I am on Debian, so no more, then ghc 7.6.3.
I found type-settheory package, but it fails to build. -- Best regards, Dmitry Bogatov <KAction@gnu.org>, Free Software supporter, esperantisto and netiquette guardian. GPG: 54B7F00D