Re: [Haskell-cafe] Usage question with TemplateHaskell and Generic
2011/11/7 José Pedro Magalhães : > Hi, > I'm not sure I understand your question. But if you mean that you want to > retrieve the type variable names, as they were defined in the source, then I > can tell you that the generic deriving mechanism cannot do this. > > Cheers, > Pedro > > On Sun, Nov 6, 2011 at 14:35, Magicloud Magiclouds > wrote: >> >> Hi, >> I'd like to simpler the work of deriving MyClass. And I have two >> ways to do: TemplateHaskell "$(derivingMyClass)", or Generic "deriving >> (MyClass)". >> Since I need to get the type name in the deriving, then I met this >> question: If I have "data A b = C b", then with TemplateHaskell, the >> type would be "VarT b", which means at compile time, I cannot get the >> exact type, so the type name would be "b". >> So I wonder if this could be resolved by TemplateHaskell, or Generic >> is the only choice. >> >> PS: I have not tried to do this in Generic. >> -- >> 竹密岂妨流水过 >> 山高哪阻野云飞 >> >> ___ >> Haskell-Cafe mailing list >> Haskell-Cafe@haskell.org >> http://www.haskell.org/mailman/listinfo/haskell-cafe > > Thank you. After deeply thinking about this, GH sure does not -- 竹密岂妨流水过 山高哪阻野云飞 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Usage question with TemplateHaskell and Generic
Hi, I'm not sure I understand your question. But if you mean that you want to retrieve the type variable names, as they were defined in the source, then I can tell you that the generic deriving mechanism cannot do this. Cheers, Pedro On Sun, Nov 6, 2011 at 14:35, Magicloud Magiclouds < magicloud.magiclo...@gmail.com> wrote: > Hi, > I'd like to simpler the work of deriving MyClass. And I have two > ways to do: TemplateHaskell "$(derivingMyClass)", or Generic "deriving > (MyClass)". > Since I need to get the type name in the deriving, then I met this > question: If I have "data A b = C b", then with TemplateHaskell, the > type would be "VarT b", which means at compile time, I cannot get the > exact type, so the type name would be "b". > So I wonder if this could be resolved by TemplateHaskell, or Generic > is the only choice. > > PS: I have not tried to do this in Generic. > -- > 竹密岂妨流水过 > 山高哪阻野云飞 > > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Usage question with TemplateHaskell and Generic
Hi, I'd like to simpler the work of deriving MyClass. And I have two ways to do: TemplateHaskell "$(derivingMyClass)", or Generic "deriving (MyClass)". Since I need to get the type name in the deriving, then I met this question: If I have "data A b = C b", then with TemplateHaskell, the type would be "VarT b", which means at compile time, I cannot get the exact type, so the type name would be "b". So I wonder if this could be resolved by TemplateHaskell, or Generic is the only choice. PS: I have not tried to do this in Generic. -- 竹密岂妨流水过 山高哪阻野云飞 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
