assignement of thrown extension to variable of type string

[andrewufrank]

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.

[andrewufrank]

example code

[igloo]

I think every use of throw would be warned about if we did this. It sounds like you want Control.Exception.throwIO instead.