Hi,
Thanks for the feedback! I have uploaded a new version of value
supply with the following changes that should improve performance.
- It uses unsafeDupableInterleaveIO to avoid double locking,
- Do not create an intermediate list for Enum and Num supples
- Specialize code for Int, as this is the most commonly used type
for new name generation.
These together should make things much faster but I have not had a
chance to test that. I looked at the core and it seemed that the
specializations were kicking in, so hopefully all is OK :)
It would be great if you could let me know if things are still slower
than the GHC version, and if so by how much.
Also, I made a git-hub repo for the code, in case anyone is interested
in contributing:
http://github.com/yav/value-supply/tree/master
-Iavor
On Mon, Dec 22, 2008 at 3:27 AM, Sebastian Fischer
Thanks for pointing me at Iavors package. We should not have two different libraries for the same purpose.
value-supply-0.2 is about 6-7 times slower than GHC's UniqSupply, but porting Simons suggestion (to use unsafeDupableInterleaveIO) into Iavors code, GHC is "only" about twice as fast.
Can we do better? I tried to use SPECIALIZE INLINE pragmas (at new[Enum|Num]Supply for Int) and/or strictness annotations (for the unique value) without significant benefit.
I like Iavors more general interface (polymorphic values) and that only demanded identifiers are created. The latter saves half of the names when evaluating
map supplyValue . split
I will replace my dependency to ghc with one to value-supply if unsafeDupableInterleaveIO is used instead of unsafeInterleaveIO where it is available.
Cheers, Sebastian _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users