On Wed, Oct 26, 2011 at 09:15:41AM -0700, Nathan Howell wrote: > On Wed, Oct 26, 2011 at 6:53 AM, Magicloud Magiclouds < > [email protected]> wrote: > > > But in Haskell, could I write a code to list the classes that a type > > instanced? > > TemplateHaskell as well. > > > > It's possible with TemplateHaskell. Look at classInstances and the ClassI > data constructor. > > http://haskell.org/ghc/docs/7.0.4/html/libraries/template-haskell-2.5.0.0/Language-Haskell-TH.html#v:classInstances
No, this lists all the instances of a class. OP asked for the classes of which a given type is an instace. Presumably it is possible, since Haddock does it! In the documentation generated for a type it lists classes of which the type is an instance. So you might want to look at how Haddock does it. I suspect the only way is through the GHC API. -Brent _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
