On Thu, Sep 8, 2011 at 3:23 PM, Sebastian Nowicki <seb...@gmail.com> wrote: > > I don't know if it's generally accepted to provide Read/Show instances > which don't parse/print Haskell syntax. >
It's quite common, and several "standard" libraries do it. Handle for example has a (fairly useless) Show instance. Whether it's a good idea or not is another question :) >>> Planned for the next release: >>> >>> * Support for parsing IPv4 notation embedded in IPv6 (e.g. "::192.168.1.1") >> >> is the result a value of type IPv4 or IPv6? For an IPv4-Compatible >> address I'd expect the result to be IPv4. It might also be useful to >> add a conversion function to turn an IPv4 address into an IPv4-Mapped >> IPv6 address. > > Technically it's an IPv6 address, "::192.168.1.1" isn't a valid IPv4 > string (hence parsing should fail). You can convert from one address > to another using toAddress . fromAddress, i.e.: > > (toAddress . fromAddress $ (readAddress "192.168.1.1" :: IPv4)) :: IPv6 > If these sorts of type coercions are often necessary, maybe you should just expose read(s)IPv4 and toIPv6 and friends? _______________________________________________ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
