[Haskell-cafe] FastString a misnomer

[Donald Bruce Stewart]

simonmar:
> On 21 October 2005 02:53, Donald Bruce Stewart wrote:
> 
> > john:
> >> On Thu, Oct 20, 2005 at 10:45:28AM +0100, Simon Marlow wrote:
> >>> I think when this is ready it should replace Data.PackedString.
> >>> 
> >>> I don't necessarily mean put it into fptools/libraries/base - we
> >>> could just remove the existing Data.PackedString from there and
> >>> your separate package can provide Data.PackedString.  That is,
> >>> unless we decide to use it in GHC in some way, in which case we'll
> >>> have to pull (a copy of) it into fptools/libraries.
> >> 
> >> We should make 'PackedString' the UTF8 wrapper though and provide
> >> Data.ByteArray as a separate library. If it has string in the name,
> >> one should be able to replace strings with it everywhere and expect
> >> the right thing to happen as enforced by the type system. that and
> >> C's conflation of characters and bytes and Haskell 98s lack of
> >> clearing up the issue has been a huge pet peeve of mine.
> > 
> > Ok, so a rough structure of the final lib would be:
> > 
> >     Data                Data                   System
> >     |                   |                      |
> >     ByteArray (?)       PackedString           Posix
> >                         |      |               |
> >                         UTF8   Latin1 ...      MMap (providing
> > mmapFile :: FilePath -> ByteArray) 
> 
> Remind me what Data.ByteArray is for?  Seems like it would overlap a lot
> with Data.PackedString.Latin1 and UArray Word8.
> 
> We should have Data.PackedString.UTF16 too; it'll make interoperating
> with Win32 APIs easier as Bulat pointed out.
> 
> I like John Meacham's suggestion of changing the UTF8 representation to
> include a count of characters as well as bytes.  I'm not volunteering to
> do it, just adding my "+1" in case anyone else wanted to :-)

Yep, ok. This goes on my todo list.

Ok, perhaps more like:

    Data                        System
    |                           |
    PackedString                Posix
    |       |    \              |
    Latin1  UTF8   UTF16        MMap

as per the current 'packedstring' of SimonM's, with the fuller interface
provided by FPS though. This was the basic plan from the start, anyway.

-- Don