[Haskell] ANNOUNCE: FPS - FastPackedStrings 0.2

[Tomasz Zielonka]

On Wed, Apr 19, 2006 at 02:52:53PM -0700, John Meacham wrote:
> I'd recommend just always using utf8 under the hood (since it shouldn't
> matter what encoding is used internally) and have two integers stored
> with the pointer, the number of bytes and the number of characters. when
> these are the same you know you have straight ASCII, plus it gives you
> O(1) length for free. I have very optimized utf8 fold operators in the
> jhc version of PackedString you can steal. they get speed by assuming
> the data is always valid UTF8 so don't do error checking, which the
> constructors always enforce. (yay for ADTs)

Nice trick, but you loose constant time indexing operations, don't you?

Best regards
Tomasz