#7897: MakeTypeRep fingerprints be proper, robust fingerprints ---------------------------------+------------------------------------------ Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | ---------------------------------+------------------------------------------ Comment(by dreixel): Just to add two comments as to why this might not have a good cost/benefit ratio: 1) The problem is not easily seen in practice. In Cloud Haskell, all nodes are supposed to run the same binary (currently, at least). And even in the example given, the result is a failed deserialisation (possibly with a sensible runtime failure), not a segfault. 2) This will complicate giving `Typeable` instances for data families. Right now, since `Typeable` only depends on the LHS of a data declaration, we can give a `Typeable` instance as soon as the family is declared; this `Typeable` instance it will work for all data instances, current and future. If we have to look at the RHS, though, we will need one separate `Typeable` instance per data family instance. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7897#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler