haskell - What *isn't* Typeable in GHC 7.8? -


i'm working author of syntactic add support wide variety of types. proposed using type lists allow any type used, dev proposed cleaner solution allows use instance of typeable.

i know (at least current version) of data.reflection doesn't support typeable reified types in ghc 7.8, @ least proposed workaround using lens.

my question original proposal library: aside (some forms of) reified types, other types in ghc 7.8 cannot made instance of typeable? if these types sufficiently strange/rare, suffice use clean solution requires typeable, if there [other] commonly used types aren't typeable, type list more general solution.

ghc.typelits.symbol , nat not typeable. see https://ghc.haskell.org/trac/ghc/ticket/9111


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