[Haskell-cafe] ANNOUNCE: vector-bytestring-0.0.0.0

[Bas van Dijk]

On 17 October 2011 16:44, Michael Snoyman <michael at snoyman.com> wrote:
> On Mon, Oct 17, 2011 at 4:42 PM, Roman Leshchinskiy <rl at cse.unsw.edu.au> wrote:
>> Michael Snoyman wrote:
>>> On Mon, Oct 17, 2011 at 12:14 PM, Bas van Dijk <v.dijk.bas at gmail.com>
>>> wrote:
>>>>
>>>> My idea is that when vector-bytestring is as fast as bytestring, it
>>>> can replace it. When that happens it doesn't matter if users use the
>>>> vector interface. I would even recommend it over using the bytestring
>>>> interface so that bytestring can eventually be deprecated in favor of
>>>> vector.
>>>
>>> +1. I'm in favor of using the OverlappingInstances/no newtype and
>>> specialized Show instance. I think that, if there was *ever* a case
>>> where OverlappingInstances was a good fit, it's this one. We're
>>> talking about a single module exporting both the base and overlapped
>>> instance, so which instance gets used should be completely decidable.
>>> (Unless of course someone defines an orphan instance elsewhere, but
>>> that's a different issue IMO.) And even in a worst-case-scenario where
>>> somehow we get the wrong instance, we're only talking about output
>>> used as a debugging aid, so the damage is minimal.
>>
>> So suppose we change the Show and Read instances for Storable vectors of
>> Word8 and Char. What happens with unboxed and boxed vectors of these
>> types? Should these be changed as well? Should these be changed as well?
>> If not, why not?
>
> I don't have any strong opinion on the matter, but it seems like they
> may as well be changed also. It seems like all the same "useful for
> debugging" arguments would apply there as well.
>
> Michael
>

Yes I think that makes sense. My patch already adds specific Show and
Read instances to all vectors of Chars and Word8s:
http://trac.haskell.org/vector/ticket/64

Bas