Copyright	(c) Bryan O'Sullivan 2009
License	BSD-style
Maintainer	bos@serpentine.com
Stability	experimental
Portability	GHC
Safe Haskell	Safe-Inferred
Language	Haskell2010

Data.Text.Internal.Unsafe.Shift

Description

Warning: this is an internal module, and does not have a stable API or name. Functions in this module may not check or enforce preconditions expected by public modules. Use at your own risk!

Fast, unchecked bit shifting functions.

Synopsis

class UnsafeShift a where
- shiftL :: a -> Int -> a
- shiftR :: a -> Int -> a

Documentation

class UnsafeShift a where Source #

This is a workaround for poor optimisation in GHC 6.8.2. It fails to notice constant-width shifts, and adds a test and branch to every shift. This imposes about a 10% performance hit.

These functions are undefined when the amount being shifted by is greater than the size in bits of a machine Int#.

Minimal complete definition

Nothing

Methods

shiftL :: a -> Int -> a Source #

default shiftL :: Bits a => a -> Int -> a Source #

shiftR :: a -> Int -> a Source #

default shiftR :: Bits a => a -> Int -> a Source #

Instances

Instances details

UnsafeShift Word16 #
Instance details Defined in Data.Text.Internal.Unsafe.Shift Methods shiftL :: Word16 -> Int -> Word16 Source # shiftR :: Word16 -> Int -> Word16 Source #
UnsafeShift Word32 #
Instance details Defined in Data.Text.Internal.Unsafe.Shift Methods shiftL :: Word32 -> Int -> Word32 Source # shiftR :: Word32 -> Int -> Word32 Source #
UnsafeShift Word64 #
Instance details Defined in Data.Text.Internal.Unsafe.Shift Methods shiftL :: Word64 -> Int -> Word64 Source # shiftR :: Word64 -> Int -> Word64 Source #
UnsafeShift Int #
Instance details Defined in Data.Text.Internal.Unsafe.Shift Methods shiftL :: Int -> Int -> Int Source # shiftR :: Int -> Int -> Int Source #