On Sun, Nov 08, 2015 at 09:36:13AM +0100, Joachim Breitner wrote:
Am Sonntag, den 08.11.2015, 01:10 +0100 schrieb Niklas Hambüchen:
In an older mail from 2010 (https://mail.haskell.org/pipermail/glasgow-haskell-users/2010-Septem ber/019237.html) I saw Simon mention that it wasn't planned to warn about inexhaustive patterns like this.
note that in that mail, he refers to patterns in where clauses, which is a different use-case than the lambdas you refer to.
[...]
Then you are in a good position to argue that it is an improvement (or you will find that SPJ, as very often, has a good instinct and making it warn about that prohibits many useful idioms.)
Simon's code is inadvisable, in my opinion. It is f xs | null xs = blah | otherwise = x+1 where (x:_) = xs where it really should be f xs = case xs of [] -> blah (x:_) -> x + 1 Tom