[Haskell-cafe] Software Tools in Haskell

[Neil Mitchell]

Hi

Having got to the word counting example on the website:

wordcount :: IO ()
wordcount = do
            wc <- wordcount' False 0
            putStrLn (show wc)
    where
    wordcount' inword wc = do
                           ch <- getc
                           case ch of
                                   Nothing -> return wc
                                   Just c -> handlechar c wc inword
    handlechar c wc _ | (c == ' ' ||
                         c == '\n' ||
                         c == '\t') = wordcount' False wc
    handlechar _ wc False = wordcount' True $! wc + 1
    handlechar _ wc True = wordcount' True wc

Eeek. That's uglier than the C version, and has no abstract components.

A much simpler version:

main = print . length . words =<< getContents

Beautiful, specification orientated, composed of abstract components.
Code doesn't get much more elegant than that. Plus it also can be made
to outperform C (http://www-users.cs.york.ac.uk/~ndm/supero/)

Thanks

Neil