#13201: Type-level naturals aren't instantiate with GHCi debugger -------------------------------------+------------------------------------- Reporter: konn | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by rwbarton): I took a quick look at this, thinking the issue would be that, in `foos`, the information of the specific type `n` is unavailable at runtime. But apparently it's not so simple, since if you write an ordinary parametrically polymorphic function like {{{#!hs myFun :: [a] -> [a] myFun l = l ++ reverse l }}} and step into `myFun`, ghci is still capable of displaying the specific type of `l`. So, my conclusion is that how this works is a mystery. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13201#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler