There was also a Show instance for CallStack in 7.10.2, is there a reason to want that? I think not, because the user shouldn't care about
#11510: Missing Show instance for GHC.Stack.SrcLoc -------------------------------------+------------------------------------- Reporter: SimonHengel | Owner: Type: bug | Status: patch Priority: high | Milestone: 8.0.1 Component: Core Libraries | Version: 8.0.1-rc1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D1886 Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): the representation. If you want a machine-readable formatting of a CallStack you can use getCallStack stk to get a list of the call-sites, which is then Showable (assuming a Show SrcLoc instance). I see the argument here but then again I think there is little harm in providing the instance. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11510#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler