[Haskell-cafe] Reading showables

[Thomas Hartman]

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 <newhoggy at gmail.com>:
> Hi,
>
> Is there a way to read Showables?
>
> main = do
>     putStrLn $ show $ read
>
> Thanks
>
> -John
>
>
> _______________________________________________
> Haskell-Cafe mailing list
> Haskell-Cafe at haskell.org
> http://www.haskell.org/mailman/listinfo/haskell-cafe
>
>