Why are strings linked lists?

[Wolfgang Jeltsch]

Am Freitag, 28. November 2003 08:49 schrieb John Meacham:
> [...]

> I also have wondered how much the string representation hurts haskell
> program performance.. Something I'd like to see (perhaps a bit less drastic)
> would be a String class, similar to Num so string constants would have type
>     String a => a
> then we can make [Char], PackedString, and whatnot instances. It should at
> least make working with alternate string representations easier.

I think, I have already said the following on this list. I would also like to 
have different character types for different subsets of Char (e.g., ASCII) 
and a class Character which the different character types are instances of.

You could combine this idea with the string class idea in the following way:
    class Character c => String s c | s -> c where
        [...]

    instance Character c => String [c] c where
        [...]

    instance String PackedString Char where
        [...]

    instance String PackedASCIIString ASCIIChar where
        [...]

>         John

Wolfgang