Re: [Haskell-cafe] Why were unfailable patterns removed and "fail" added to Monad?

On 2012-01-24 05:32, Michael Snoyman wrote:

On Fri, Jan 20, 2012 at 6:52 AM, Michael Snoyman wrote:

...

provide an extra warning flag (turned on by -Wall) that will warn when you match on a failable pattern.

I've filed a feature request for this warning: http://hackage.haskell.org/trac/ghc/ticket/5813

Thanks! I wish the compiler could tell the difference between monads that handle failure nicely (e.g. List) and those that throw a runtime error (e.g. IO). Something's wrong -- I'm feeling nostalgic for MonadZero.