[Haskell] Re: Parameterized Show

[Keean Schupke]

Easy:

    data ShowHex a
    instance Show (ShowHex a) where
       showsPrec _ (ShowHex a) = showHex a

    main = putStrLn $ (show (ShowHex 27))

Here, with labelled instances you would write:

    show ShowHex 27

instead you write:

    show (ShowHex 27)


    Keean.

George Russell wrote:

> Keean Schupke wrote:
>
>> Do you need a language extension at all? You can certainly
>> do it with the existing extensions!
>>
>> data ShowDict a
>> instance Show (ShowDict a) where
>>    showsPrec _ (ShowDict a) = ...
>
>
> I don't understand.  How does that help you to, for example, use a 
> function which
> requires Show Int but (say) substitute the standard function for which 
> which shows
> in hexadecimal?
>
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