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

On Thu, Jan 19, 2012 at 8:53 PM, Edward Z. Yang wrote:

It's not obvious that this should be turned on by -Wall, since you would also trigger errors on uses like:

   [ x | Just x <- xs ]

I was going to say, perhaps refutable matches were considered important was because back then list and monad comprehensions were still the same. List-comps is the only place I use refutable matches, but they're extremely handy. I would have suggested that listcomp match failures yield [] but monad ones be errors, but now that list comps and monads are back together again maybe that's not so easy to do...