[Haskell-cafe] ANN: text 0.5,
a major revision of the Unicode text library
jeremy at n-heptane.com
Fri Oct 9 16:27:03 EDT 2009
oops, for the sake of completeness you also need:
textType = mkStringType "Data.Text"
On Oct 9, 2009, at 10:33 AM, Jeremy Shaw wrote:
> What are the chances of seeing a, instance Data Text, some day? text
> would be a great type to use with Happstack, because it is far more
> memory efficient than String. But it is difficult to do that with
> out a instance of Data.
> For the time being, I have been hacking it with:
> instance Data Text where
> toConstr x = mkStringConstr textType (Text.unpack x)
> gunfold _k z c = case constrRep c of
> (StringConstr x) -> z (Text.pack x)
> _ -> error "gunfold for Data.Text"
> dataTypeOf _ = textType
> But, packing and unpacking the Text is obviously not that cool..
> For what it's worth, ByteString is normally exported abstract, and
> just uses, deriving Data. Perhaps we can do the same for text? (I
> believe there are a number of other examples of types in the
> 'standard' libraries which are exported abstract, but have Data
> - jeremy
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