On Tue, Apr 24, 2012 at 10:55, Michael Snoyman <mich...@snoyman.com> wrote: > On Tue, Apr 24, 2012 at 11:36 AM, Erik Hesselink <hessel...@gmail.com> wrote: >> On Tue, Apr 24, 2012 at 08:32, Michael Snoyman <mich...@snoyman.com> wrote: >>> Here's a theoretically simple solution to the problem. How about >>> adding a new method to the IsString typeclass: >>> >>> isValidString :: String -> Bool >> >> If you're going with this approach, why not evaluate the conversion >> from String immediately? For either case you have to know the >> monomorphic type, and converting at compile time is more efficient as >> well. But we're getting pretty close to Template Haskell here. > > I could be mistaken, but I think that would be much harder to > implement at the GHC level. GHC would then be responsible for taking a > compile-time value and having it available at runtime (i.e., lifting > in TH parlance). Of course, I'm no expert on GHC at all, so if someone > who actually knows what they're talking about says that this concern > is baseless, I agree that your approach is better.
But GHC already has all the infrastructure for this, right? You can do exactly this with TH. Erik _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
