In case this wasn't clear, the context of this discussion in this GHC
proposal [1], where David is trying to work around the fact that data types
with existential Coercible constraints do not support unpacking. (By
"unpacking", I mean putting an {-# UNPACK #-} pragma in front of a field of
that type does what you would expect.)An example program which demonstrates the performance issue can be found here [2]. That comment concerns unboxed equality vs. boxed equality, but the same unpacking problems that affect boxed equality also affect Coercible. Ryan S. ----- [1] https://github.com/ghc-proposals/ghc-proposals/pull/116 [2] https://github.com/ghc-proposals/ghc-proposals/pull/116#issuecomment-382346662
_______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
