Re: [Haskell-cafe] Reading showables

Given two different types T1 and T2, it's possible to have two different results of

let {x :: T1; x = read s} in show x

and

let {x :: T2; x = read s} in show x

so that neither of two "read"s fails. For example

let {x :: Int; x = read "1000000000000"} in show x

produces the answer "-727379968". BTW, I'd love to be able to give default instances locally, so that something like

main = withdef Read Int {putStrLn $ show $ read "1000000000000"}

would typecheck successfully. On 7 Dec 2008, at 16:11, John Ky wrote:

Hi,

Is there a way to read Showables?

main = do putStrLn $ show $ read

Thanks

-John

_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe