[Haskell-cafe] Clever generic ByteString hack?
jgoerzen at complete.org
Wed Jul 5 09:16:13 EDT 2006
On Wed, Jul 05, 2006 at 12:25:53PM +0100, Duncan Coutts wrote:
> > different types of input? I'd rather avoid having 3 versions, that are
> > exactly the same except for imports.
> People sometimes talk about doing a type class to cover string like
Yes, that makes sense to me. I was sorta hoping to avoid having to say
instance StringLike B.ByteString where
vlength = B.length
vcons = B.cons
... with about 50 of these lines ...
> What functions are you thinking of btw? We may want to include them in
> the ByteString modules anyway (possibly directly rather than in terms of
> other functions, to take advantage of tricks with the representation).
Most everything here:
The appropriate bits from:
And perhaps even:
Also, it would be nice to see direct regexp support in ByteString. It
seems ugly to have to convert to a String just to pass it back to C.
But even if you did implement all of that, I think there is still
utility in having a generic typeclass that can take any of the three
string-like types that we have in Haskell these days. Otherwise, you
are going to see library fracturization -- some code works with Strings,
some with ByteStrings, some with lazy ByteStrings, and woe to the
programmer that has to integrate all this mess.
(OCaml has this problem in a big way with its lists vs. Streams and
built-in handicapped IO vs. Posix IO)
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