Re: [Haskell-cafe] Reading showables

Hi Thomas, So "show . read" and "\x -> show (read x)" are actually mean different things? Also, I never suspected that something like this should succeed: putStrLn $ (read . show) $ "!@#%$^DFD" Thanks, -John On Mon, Dec 8, 2008 at 12:38 AM, Thomas Hartman wrote:

John,

By convention, read . show is supposed to be id.

However, in real life, this is often not the case. It all depends on the implementor, and this is a convention that seems to be broken pretty frequently.

Often there is a show instance with no read or vice versa, and sometimes even when there is both read and show they are not inverses.

Thomas.

main = show . read

Am 7. Dezember 2008 14:11 schrieb John Ky :

...

Hi,

Is there a way to read Showables?

main = do putStrLn $ show $ read

Thanks

-John

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