strict-identity: Strict Identity Monad, handy for writing fast code!
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| 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 | 1973 total (19 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
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#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