Dear List, I have some questions about the inner parts of GHC, where I need to learn a lot. This is related to my attempts on newtype casting, but should probably be kept separate from the conceptual discussions. Say I need to create a wired-in type class, because it cannot be represented in Haskell. The Core type constructor that will come out of it will have one field of type ~R#, which is the reason why I cannot write it in Haskell. It seems that defining something wired-in is not a very local operation that affects, at least primops.txt.pp and TysPrim.lhs. Does it affect more? It seems that there is not precedent of a wired-in type class. Is that possible without touching too many parts of the compiler? Or is it saner to just have "class NT a b" in a module in ghc-prim without the constraint and use special magic when compiling that file to add the required field to the data constructor representing the class? (Similar to how the kind of ~ is adjusted during compilation?) Greetings, Joachim -- Joachim “nomeata” Breitner mail@joachim-breitner.de • http://www.joachim-breitner.de/ Jabber: nomeata@joachim-breitner.de • GPG-Key: 0x4743206C Debian Developer: nomeata@debian.org