#5910: Holes with other constraints ----------------------------------------+----------------------------------- Reporter: xnyhps | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler (Type checker) | Version: 7.5 Keywords: holes | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: Other Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | ----------------------------------------+----------------------------------- Changes (by spl):
* failure: Incorrect warning at compile-time => Other Comment: If {{{-XHoles}}} is set, we want the following: * The program should be type-checked as if every hole {{{_?h}}} is replaced by {{{undefined}}}, except: * If type-checking would fail due to unsolved constraints that could be solved by giving a type to a hole. * If the program is well-typed, then: * The types of all holes should be reported. * Reporting the hole types should not cause type-checking (or compiling in general) to stop (in error). * (optional) If the program is ill-typed, then: * The types of all holes should be reported. The above should hold true with and without the monomorphism restriction. In particular, if an {{{undefined}}} somewhere in a program type-checked with the monomorphism restriction would cause type-checking to fail, then a hole in that same position should also cause type-checking to fail. The type of a hole should be the resolved type with minimum constraints. That is, the type of a hole should only have constraints that have not be solved but are either inferred from the context (e.g. {{{show _?h}}}) or given in a type annotation/signature (e.g. {{{_?h :: Show a => a}}}. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5910#comment:12> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler _______________________________________________ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs