cvs commit: fptools/ghc/compiler/typecheck TcBinds.lhs TcSimplify.lhs fptools/ghc/compiler/types Class.lhs FunDeps.lhs Type.lhs

[Simon Peyton Jones]

simonpj     2001/05/03 02:32:49 PDT

  Modified files:
    ghc/compiler/typecheck TcBinds.lhs TcSimplify.lhs 
    ghc/compiler/types   Class.lhs FunDeps.lhs Type.lhs 
  Log:
  	------------------------------------------------
  	Dramatically improve the error messages arising
  	from failed unifications triggered by 'improvement'
  	------------------------------------------------
  
  A bit more plumbing in FunDeps, and consequential wibbles elsewhere
  
  Changes this:
  
      Couldn't match `Int' against `[(String, Int)]'
  	Expected type: Int
  	Inferred type: [(String, Int)]
  
  to this:
  
      Foo.hs:8:
  	Couldn't match `Int' against `[(String, Int)]'
  	    Expected type: Int
  	    Inferred type: [(String, Int)]
  	When using functional dependencies to combine
  	  ?env :: Int, arising from a type signature at Foo.hs:7
  	  ?env :: [(String, Int)],
  	    arising from use of implicit parameter `?env' at Foo.hs:8
  	When generalising the types for ident
  
  Revision  Changes    Path
  1.89      +9 -4      fptools/ghc/compiler/typecheck/TcBinds.lhs
  1.75      +15 -6     fptools/ghc/compiler/typecheck/TcSimplify.lhs
  1.35      +5 -1      fptools/ghc/compiler/types/Class.lhs
  1.14      +34 -23    fptools/ghc/compiler/types/FunDeps.lhs
  1.83      +8 -2      fptools/ghc/compiler/types/Type.lhs