#9898: Wanted: higher-order type-level programming -------------------------------------+------------------------------------- Reporter: erisco | Owner: Type: feature | Status: new request | Milestone: Priority: normal | Version: 7.8.3 Component: Compiler | Keywords: (Type checker) | Architecture: x86_64 (amd64) Resolution: | Difficulty: Unknown Operating System: Windows | Blocked By: Type of failure: GHC | Related Tickets: rejects valid program | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by jstolarek):
Does applying a type family to no arguments count as being partially applied? Yes. To be more precise: you can't have *unsaturated* type families, where unsaturated means "applied to less arguments than it's arity".
will such usage be banned n 7.8.4? No. But that's still a bug and you shouldn't construct your code around this.
What is a good place for Q&A on type level programming in Haskell? Haskell-cafe.
If you really want partial application at the type level you can try out `singletons`, as suggested by Richard. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9898#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler