Hi!
A couple of months ago, I wrote an exam in an introductory Haskell course and
failed, all because of an assignment that I was convinced would work, but for
some reason, it didn't. The assignment was to write a function that would take
a line, then determine whether it's a palindrome or not. My code follows:
palindrome :: IO ()
palindrome = do putStr "Type in a word"
s <- getLine
case s of
(s == reverse s) -> putStrLn (s ++ " is a palindrome")
otherwise -> putStrLn (s ++ " is not a palindrome")
The interesting thing is, that if I change the "case ... of" statement to an
"if ... then ... else" statement, this magically starts to work. Since I no
longer am enrolled (I have to take the course next year), I can't ask a
teacher, but my curiosity still bugs me. Why doesn't this work? And why does it
work with a "if ... then ...else" statement?
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