Am 20.10.2011 21:43, schrieb Michael Snoyman:
On Wed, Oct 19, 2011 at 9:29 PM, Ketil Malde<ke...@malde.org> wrote:
Michael Snoyman<mich...@snoyman.com> writes:
sense to try and pursue something like what you're suggesting, but I
think the default Show (Vector Word8) should be the one most useful,
most of the time, and I think the general consensus seems to be the
current ByteString instance fits that role.
Hm. I think it is slightly weird to display a numeric value (Word8) as
a Char. Also, I would prefer a representation making the type explicit
(but unlike ByteString, vector seems to add a type annotation.) Would
you still support the truncating behavior for 'read' and values above 255?
(ByteString has two interfaces, ByteString and .Char8, but as there can
be only one Show instance, I see why it works the way it does.)
Perhaps the correct semantic approach would be to have:
newtype Char8 = Char8 Word8
But I think that will break far too many applications to try to get it
would a new Word8 type be better to stay compatible?
newtype Word8 = C8 Data.Word.Word8
C.
implemented. In an ideal world, I agree with both points: displaying a
numeric value as a Char doesn't make sense, and there are definitely
issues with the Read instance. However, I still think current behavior
is the least of all available evils. Show/Read work properly as a pair
and can encode/decode any ByteString, and there's never any
presumption that all input to read is valid.
Michael
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