Dominic, if you want to remove yourself from maintainer hood that's cool.
I'm keen on finishing up my random v2 release which is a much improved breaking Change.
I spent part of my holiday this year working on it.
Dominic: I'm confused and surprised by your email after we had a one hour phone chat about this topic last week.
I'm disappointed you are still raising concerns I addressed and explained to you last week.
Random v2 is in flight. You are welcome to stop being involved.
I wanted to give an update on the status of random numbers in Haskell.
1. It is well known that the random number generator package
https://hackage.haskell.org/package/random gives unexpected
results.
2. Most people do *not* use it. I believe
https://hackage.haskell.org/package/mwc-random is a popular choice
but developers are free to use e.g. Mersenne Twister, PCG
(Permuted Congruential Generator), TF (ThreeFish) and many others.
3. Approximately 2 years, I made a proposal to replace the algorithm
within random (https://hackage.haskell.org/package/random) with
that used by tf-random
(https://hackage.haskell.org/package/tf-random) which is used by
QuickCheck. In summary, the response to this was that someone
should do more research with the result that nothing happened.
4. In the meantime, random
(https://hackage.haskell.org/package/random) is *no longer* a core
library. It's just a library with the same status as
e.g. mwc-random. However, it has one difference: it uses the name
for its module: "System.Random". Other RNGs use
"System.Random.MWC", "System.Random.PCG", "System.Random.Mersenne"
etc.
As a maintainer of random
(https://hackage.haskell.org/package/random), my proposal now is to
deprecate all of it.
I am not clear what the policy is on namespace usage. Could every RNG
use the module name "System.Random"? Or is this somehow reserved? If
the latter then I propose that *nothing* uses this name and that all
RNGs should add a suffix indicating which algorithm they use.
They *could* use the same namespace but I don't recommend it. If someone depends on two of these packages they would have to use PackageImports. Tools such as doctest break if a package db has module conflicts, even if only one of the packages is listed as a dependency.
Cheers,
Adam
I note that the Haskell Platform contains tf-random so users of this
will still be able to generate (better) random numbers.
If someone comes along in the future, as I hope they do, and
implements e.g. Guy Steele's splitmix algorithm then this can occupy
the name "System.Random.Splitmix" and have the package name
"random-splitmix".
The advantages of doing this are:
1. Neophyte (and experienced) Haskellers do not accidentally use an
RNG which gives unexpected results.
2. No-one will any longer be able to write blogs or papers about this
embarrassing aspect of Haskell.
I believe the co-maintainer of random
(https://hackage.haskell.org/package/random), Carter Schonwald, has a
different view on this matter but it is best he speaks for himself
rather than me imperfectly trying to reflect his thinking.
Dominic Steinitz
dominic@steinitz.org
http://idontgetoutmuch.wordpress.com
_______________________________________________
Libraries mailing list
Libraries@haskell.org
http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries
_______________________________________________
Libraries mailing list
Libraries@haskell.org
http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries