#15322: `KnownNat` does not imply `Typeable` any more when used with plugin -------------------------------------+------------------------------------- Reporter: chshersh | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.4.3 Resolution: | Keywords: | typeable,knownnat Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: #10348 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by diatchki): Well, the evidence for `KnownNat` is just a simple integer, while the corresponding `TypeRep` is a much more heavy-weight structure, containing hashes, strings, etc. Since these are created on demand for type- literals, we would be doing additional allocation and hashing at run-time. There are many cases where `KnowNat` is useful without the additional functionality provided by `Typeable`, so I think that the current system makes sense. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15322#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler