Safe Haskell	None
Language	Haskell2010

Data.Falsify.WordN

Contents

Construction
Using

Description

N-bit words

Intended for qualified import.

import Data.Falsify.WordN (WordN)
import qualified Data.Falsify.WordN as WordN

Synopsis

data WordN
newtype Precision = Precision Word8
forgetPrecision :: WordN -> Word64
zero :: Precision -> WordN
truncateAt :: Precision -> Word64 -> WordN
unsafeFromWord64 :: Precision -> Word64 -> WordN
toProperFraction :: WordN -> ProperFraction

Documentation

data WordN Source #

n-bit word

Instances

Instances details

Show WordN Source #
Instance details Defined in Data.Falsify.WordN Methods showsPrec :: Int -> WordN -> ShowS # show :: WordN -> String # showList :: [WordN] -> ShowS #
Eq WordN Source #
Instance details Defined in Data.Falsify.WordN Methods (==) :: WordN -> WordN -> Bool # (/=) :: WordN -> WordN -> Bool #
Ord WordN Source #
Instance details Defined in Data.Falsify.WordN Methods compare :: WordN -> WordN -> Ordering # (<) :: WordN -> WordN -> Bool # (<=) :: WordN -> WordN -> Bool # (>) :: WordN -> WordN -> Bool # (>=) :: WordN -> WordN -> Bool # max :: WordN -> WordN -> WordN # min :: WordN -> WordN -> WordN #

newtype Precision Source #

Precision (in bits)

Constructors

Precision Word8

Instances

Instances details

Enum Precision Source #
Instance details Defined in Data.Falsify.WordN Methods succ :: Precision -> Precision # pred :: Precision -> Precision # toEnum :: Int -> Precision # fromEnum :: Precision -> Int # enumFrom :: Precision -> [Precision] # enumFromThen :: Precision -> Precision -> [Precision] # enumFromTo :: Precision -> Precision -> [Precision] # enumFromThenTo :: Precision -> Precision -> Precision -> [Precision] #
Num Precision Source #
Instance details Defined in Data.Falsify.WordN Methods (+) :: Precision -> Precision -> Precision # (-) :: Precision -> Precision -> Precision # (*) :: Precision -> Precision -> Precision # negate :: Precision -> Precision # abs :: Precision -> Precision # signum :: Precision -> Precision # fromInteger :: Integer -> Precision #
Show Precision Source #
Instance details Defined in Data.Falsify.WordN Methods showsPrec :: Int -> Precision -> ShowS # show :: Precision -> String # showList :: [Precision] -> ShowS #
Eq Precision Source #
Instance details Defined in Data.Falsify.WordN Methods (==) :: Precision -> Precision -> Bool # (/=) :: Precision -> Precision -> Bool #
Ord Precision Source #
Instance details Defined in Data.Falsify.WordN Methods compare :: Precision -> Precision -> Ordering # (<) :: Precision -> Precision -> Bool # (<=) :: Precision -> Precision -> Bool # (>) :: Precision -> Precision -> Bool # (>=) :: Precision -> Precision -> Bool # max :: Precision -> Precision -> Precision # min :: Precision -> Precision -> Precision #

forgetPrecision :: WordN -> Word64 Source #

Forget the precision of the WordN

Construction

zero :: Precision -> WordN Source #

Zero can be represented at every precision

truncateAt :: Precision -> Word64 -> WordN Source #

Make n-bit word (n <= 64)

Bits outside the requested precision will be zeroed.

We use this to generate random n-bit words from random 64-bit words. It is important that we truncate rather than cap the value: capping the value (limiting it to a certain maximum) would result in a strong bias towards that maximum value.

Of course, shrinking of a Word64 bit does not translate automatically to shrinking of the lower n bits of that word (a decrease in the larger Word64 may very well be an increase in the lower n bits), so this must be taken into account.

unsafeFromWord64 :: Precision -> Word64 -> WordN Source #

Construct from Word64

It is the caller's responsibility to ensure that the Word64 is in range.

Using

toProperFraction :: WordN -> ProperFraction Source #

Compute fraction from n-bit word