> On Nov 10, 2014, at 09:46, Adam Gundry <a...@well-typed.com> wrote: > > On 10/11/14 15:58, Austin Seipp wrote: >> - 2) I am kind of not a fan of having separate 'plugins for >> core2core' and 'plugins for typechecking' flags, AKA -ftc-plugin and >> -fplugin. Ideally I would think all plugins could be uniformly >> specified by simply saying '-fplugin'. This mostly avoids the need for >> duplication and a naming convention/slew of flags for each case (which >> we have to catalog and document). There may be an easy way to make >> this the case; I haven't looked closely yet (it has been some time >> since I starred at the plugin code, even though Max wrote it and I >> helped get it merged!) > > FWIW, I originally envisaged reusing the existing plugins machinery, and > I don't think there are any great problems in doing so (see > https://ghc.haskell.org/trac/ghc/wiki/Plugins/TypeChecker). In fact, I > had an early implementation of typechecker plugins that did exactly this. > > I have been wondering, however, about another possible approach. We could: > > 1. make the constraint solver changes use a *hook*, instead of the > plugins directly, and > > 2. make it possible for plugins to install/modify hooks at some > suitable point in the compilation pipeline. > > I don't know the hooks machinery very well, but if this is feasible it > seems like it would provide more power (plugins could modify any part of > GHC for which a hook is available) and avoid having multiple overlapping > ways of extending GHC. In the future, I can imagine wanting plugins to > hook into other parts of GHC (e.g. error message postprocessing for > domain-specific error reporting), and this seems like a good way to > achieve that.
I think we could merge the TcPlugin type into the existing Plugin type without much difficulty, but I also agree that combining both plugin types with Hooks to present a more uniform interface would be nice. Eric _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://www.haskell.org/mailman/listinfo/ghc-devs
