[GHC] #3876: assignement of thrown extension to variable of type string

[GHC]

#3876: assignement of thrown extension to variable of type string
---------------------------------+------------------------------------------
    Reporter:  andrewufrank      |       Owner:              
        Type:  bug               |      Status:  new         
    Priority:  normal            |   Component:  Compiler    
     Version:  6.10.4            |    Keywords:              
          Os:  Unknown/Multiple  |    Testcase:              
Architecture:  Unknown/Multiple  |     Failure:  None/Unknown
---------------------------------+------------------------------------------
 in an unusual case (exception thrown in code in the return) the thrown
 exception is returned from the function and then assigned to a variable
 with another type (e.g. string); if the variable is later evaluated, the
 exception is then actually thrown there (and not in the original
 function).

 the bug is the problem in the asignement of a thrown exception to another
 type. the coding style is unfortunate and not encourage, but the compiler
 should report an error.

 (code like
              = do ...
                 return (case x of
                            0 -> throw Anexception
                         )
 produces the error.




 i attach a file to demonstrate the problem.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3876>
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