strict-identity: Strict Identity Monad, handy for writing fast code!
Downloads
- strict-identity-0.1.0.0.tar.gz [browse] (Cabal source package)
- Package description (revised from the package)
Note: This package has metadata revisions in the cabal description newer than included in the tarball. To unpack the package including the revisions, use 'cabal get'.
Maintainer's Corner
For package maintainers and hackage trustees
Candidates
| Versions [RSS] | 0.1.0.0 |
|---|---|
| Change log | changelog.md |
| Dependencies | base (>=4.3 && <5.0) [details] |
| License | BSD-3-Clause |
| Author | Carter Tazio Schonwald |
| Maintainer | carter at wellposed.com |
| Revised | Revision 1 made by CarterSchonwald at 2017-02-15T01:12:11Z |
| Category | Control |
| Home page | https://github.com/cartazio/strict-identity |
| Source repo | head: git clone http://github.com/cartazio/strict-identity.git |
| Uploaded | by CarterSchonwald at 2014-01-12T08:25:22Z |
| Distributions | Arch:0.1.0.0, NixOS:0.1.0.0 |
| Reverse Dependencies | 2 direct, 1 indirect [details] |
| Downloads | 1954 total (20 in the last 30 days) |
| Rating | (no votes yet) [estimated by Bayesian average] |
| Your Rating | |
| Status | Docs available [build log] Successful builds reported [all 1 reports] |
Readme for strict-identity-0.1.0.0
[back to package description]
#About
strict-identity package is meant to make writing nested strict let expression heavy code a bit more pleasant, for all those High Performance Haskell lib authors out there.
A simple example of the strict identity monad in action (and working wonderfully) is the following bit fiddling code, which generates C competitive assembly on both major GHC backends, -fasm and -fllvm
(>>) = unsafeShiftR
(<<) = unsafeShiftL
outerShuffle64A :: Word -> Word
outerShuffle64A !x =
runStrictIdentity $! do
x <- return $! ((x .&. 0x00000000FFFF0000) << 16 )
.|. ((x>>16) .&. 0x00000000FFFF0000) .|. (x .&. 0xFFFF00000000FFFF)
x <- return $! ((x .&. 0x0000FF000000FF00 ) << 8 )
.|. (x >> 8) .&. 0x0000FF000000FF00 .|. (x .&. 0xFF0000FFFF0000FF)
x<- return $! (( x .&. 0x00F000F000F000F0 ) << 4 )
.|. (x >> 4) .&. 0x00F000F000F000F0 .|. (x .&. 0xF00FF00FF00FF00F )
x<- return $!((x .&. 0x0C0C0C0C0C0C0C0C )<< 2 )
.|. (x >> 2) .&. 0x0C0C0C0C0C0C0C0C .|.( x .&. 0xC3C3C3C3C3C3C3C3)
x<- return $! ( (x .&. 0x2222222222222222) << 1 )
.|. (x>> 1) .&. 0x2222222222222222 .|. (x .&. 0x9999999999999999)
return x