On Fri, Feb 03, 2006 at 11:38:09AM -0800, Isaac Jones wrote:
I would like to strive to find objective data on the use of extensions. I started a table here which summarizes how popular extensions are in real-life code. We need more data points, though.
http://hackage.haskell.org/trac/haskell-prime/wiki/ExtensionsExperiment
I have a short program which queries the hackage database, gets some details about all of the packages there, and summarizes them into a table.
I'm not sure how useful this info is, as: * You won't get, for example, FunctionalDependencies from any libraries or applications that make use of Control.Monad.State. * Many extensions turn into -fglasgow-exts/-98, so if I use functional dependencies and rank 2 types but only declare FunctionalDependencies and not Rank2Types then nothing is going to tell me I've made a mistake. (I think it would be great if this was fixed). (Ideally something could warn about unused extensions too, but that's trickier). * People will sometimes be willing to jump through hoops to avoid using an unportable extension. That said, FWIW, I have the following in my cabalised libraries (none in hackage AFAIK): * ForeignFunctionInterface, TemplateHaskell, TypeSynonymInstances * TypeSynonymInstances * ForeignFunctionInterface * ForeignFunctionInterface * EmptyDataDecls, CPP * EmptyDataDecls, ForeignFunctionInterface Thanks Ian