Hi, the reference suggests the use of otherwise (instead of _) as the default pattern in a case expression. While it certainly works, isn’t it bad style, as it shadows Prelude.otherwise: $ cat otherwise.lhs ; runhaskell otherwise.lhs
demo b arg = case b of True -> do print "First arg was True" let g | arg == "Something" = print "Got something" | otherwise = print "Got anything else" g otherwise -> do print "First arg was not True" let g | arg == "Something" = print "Got something" | otherwise = print "Got anything else" g
main = do demo True "Something" demo True "Something else" demo False "Something" demo False "Something else" "First arg was True" "Got something" "First arg was True" "Got anything else" "First arg was not True" "Got something" "First arg was not True" otherwise.lhs: otherwise.lhs:(7,36)-(8,86): Non-exhaustive patterns in function g
I know that this is a contrieved example (using case on a boolean), but in other cases you’ll get strange type errors. So while I think I did it in the past, otherwise should be avoided in case expressions. Greetings, Joachim -- Joachim "nomeata" Breitner mail: mail@joachim-breitner.de | ICQ# 74513189 | GPG-Key: 4743206C JID: nomeata@joachim-breitner.de | http://www.joachim-breitner.de/ Debian Developer: nomeata@debian.org