Ian Lynagh
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:
There are definitely imperfections in the data, but surely the actual data about which extensions are being used in real code is relevant.
* You won't get, for example, FunctionalDependencies from any libraries or applications that make use of Control.Monad.State.
I suppose we could try to chase down those dependencies. If Package A depends on Package B, and Package B uses extension X, then perhaps we could count package A as half a point for extension X. All the data is there, this would be pretty easy to add.
* 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.
True enough, but I think people know when they are using extensions. One solution would be to make sure that all extensions have their own flag instead of so many going to -fglasgow-exts. (snip)
* 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):
If you give me links, I'll upload them, or you could upload them as per the instructions on the wiki. peace, isaac