24 May
2017
24 May
'17
4:02 p.m.
On Wed, May 24, 2017 at 3:13 AM, Anthony Clayden
On Wed May 24 02:33:46 UTC 2017, Richard Eisenberg wrote:
I agree here, but it's a bit subtler. We aren't confused when we see
f [] = False f _ = True
Oh, yes I think a lot of people are confused. I think they expect the second equation is equivalent to:
f (x:xs) = True
Maybe even
f ~(x:xs) = True
But in the presence of bottom, that's a dangerous delusion.
I would argue those are equivalent. To get to the second equation, you
would have had to reject the first equation, so at that point you
already know the argument isn’t bottom.
--
Dave Menendez