Ivan Miljenovic wrote:
> Johan Tibell wrote:
>> A sequence of bytes is not the same thing as a sequence of Unicode
>> code points. If you want to replace String by something more efficient
>> have a look at Data.Text.
>
> Though Data.Text still has the disadvantage of not being as nice to
> deal with as String, since you can't pattern match on it, etc.
>
> Whilst it may degrade performance, treating String as a list of
> characters rather than an array provides you with greater flexibility
> of how to deal with it.
Indeed. In particular, [Char] and Data.Text.Text have different
semantics and performance.
For instance,
cons :: Char -> Text -> Text
is O(n) whereas (:) is O(1). (Not sure whether stream fusion for cons
can change that at times.)
Furthermore, certain programs relying on laziness, like
ahh = 'a' : ahh
fibs = ' ' : zipWith plus fibs (tail fibs)
where plus x y = toEnum $ fromEnum x + fromEnum y
are not possible with Data.Text.Text . (Whether you really need these
is another question, of course.)
Regards,
Heinrich Apfelmus
--
http://apfelmus.nfshost.com
_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
