On Fri, 2013-05-24 at 09:30 +0200, Petr Pudlák wrote:
Dne 24.5.2013 04:57, Bardur Arantsson napsal(a):
I'm a bit surprised I haven't seen anyone mention it, but the Go community have a tool which can automate a lot of the tedium of API transitions:
http://blog.golang.org/2011/04/introducing-gofix.html
Maybe I'm missing something, but surely this kind of tool (a "hlint on steriods", I guess) could be written for many of the breaking changes that have been suggested in recent days on this list.
Gofix specifically doesn't try to fix absolutely *everything*, but it fixes all the trivial stuff which is extremely annoying, but automatable, such as import lists, module/function renames, etc. (For a recent example, see "catch".)
Heck, one could even imagine building in a "--future" mode into such a program to handle changes "one version ahead" during the deprecation cycle (which I assume we're not getting rid of). It could, for example, start issuing appropriate warnings for the Applicative => Monad transition. (Which would mean that we wouldn't need ad-hoc modifications to GHC to support such transitions.)
AFAICT having such a tool in the Go ecosystem has been a huge boon, at least while the language and APIs were developing and in the transition from Go 1.0 to 1.1.
I'd also support the suggestion of making several changes at once, that solve many recurring problems. For me it's easier to make one big upgrade to my code once, than to make a small upgrade every now and then if the language changes in small steps.
The idea of making an automated tool is really great, I was just thinking about something similar. Some changes would be really trivial, like adding "import Interlude". Some would be slightly more complex, like refactoring Monad instances into Applicative+Monad, but I believe it'd be very well possible.
This has been coined on haskell-cafe some time ago as well, see [1] and [2]. Nicolas [1] http://www.haskell.org/pipermail/haskell-cafe/2013-May/108086.html [2] http://www.haskell.org/pipermail/haskell-cafe/2013-May/108087.html