[Haskell-cafe] discouraging unsafePerformIO (Was: Debugging partial functions by the rules)

On Wed, 15 Nov 2006 oleg@pobox.com wrote:

... I'd be quite happy seeing fromJust removed from the standard libraries, or at least tagged `deprecated' or with the stigma attached that is rightfully accorded to unsafePerformIO.

However, unsafe* functions are still recommended by Haskell users to newbies, as if these functions belong to the normal usage. Maybe one should add a string parameter to these functions, which must be bound to "I confirm that I know that this function should be used only if really necessary and that I checked properly that safe alternatives do not exist.". The unsafe* function must be undefined, if the confirmation argument does not match. :-)