On 30/05/13 23:50, Gan Uesli Starling wrote:

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As compared against Python and Perl, how stable is Haskell?

I must say, I find the comparison odd. The transition from imperative to declarative programming must be much more mind-bogging than figuring out how to deal with instability. Surely, there are both more and less stable options within each paradigm. On Fri, May 31, 2013 at 12:23:00AM +0100, Mateusz Kowalczyk wrote:

I think you're actually asking ``how much does Haskell change between revisions'' and not how stable it is. If you're looking for a language where your program will work with a compiler that's 5 years old or 5 years from now, this probably isn't it. It's not like programs break daily because of the changes but I believe there is no hesitation to change stuff because some program from 5 years ago might no longer compile.

It may be useful to distinguish between stability of the language and stability of the libraries. Talking about libraries, you are probably right. In fact, I have tried to install a number of libraries from hackage recently, and only about half of them succeeded. The typical problem with the others seem to be changes in their dependencies. Typical age is about 3-6 years, I think. Python however, is not even stable in terms of core language. Although library evolution can also break your program, such breakage is generally easier to repair. The problem for haskell, of course, is that the community is too small to sustain a standard library of the extent seen for python or java. Hence one relies much more on beta versions and stale libraries. That does not make haskell any less stable; it is a very different kind of problem. -- :-- Hans Georg