#10316: Move Typeable type-rep generation from use site to definition site -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.12.1 Component: Compiler | Version: 7.10.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- This ticket is a continuation of #9858. The interim solution for 7.10 was to generate `Typeable` data structures on the fly, as needed in client modules. This ticket is about moving the generation of the runtime representation of type constructors to their definition sites. (#9858 already has too much going on in it, so I started a fresh ticket for this refactoring.) The branch is `wip/T9858-typeable-spj`. In favour of (A) code at use site (as in 7.10): * Pay as you go. No code at all is generated unless you use `Typeable` In favour of (B) code at definition site: * More sharing. We make a `TyCon` (see `Data.Typeable.Internal`) for `T` (say) just once, in the module that defines `T`. * We may ultimately want the `TyCon` for `T` to include its source location, and perhaps more besides. If it is defined in `T` it becomes easier to do that. General observation: (B) is like `Typeable` was before, when it was an ordinary class. The difference now is that all types are `Typeable`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10316 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler