LegacyNumeric.hs

{-# LANGUAGE CPP #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}

{-

Contents of this file copyright the QuickCheck team, 2010.
QuickCheck was available under the BSD3 license at that time. 

-}

module Test.QuickCheck.Instances.LegacyNumeric() where

#if !(MIN_VERSION_QuickCheck(2,1,2))

import Data.Int
import Data.Word
import Test.QuickCheck.Arbitrary
import Test.QuickCheck.Gen

-- | Generates an integral number from a bounded domain. The number is
-- chosen from the entire range of the type, but small numbers are
-- generated more often than big numbers. Inspired by demands from
-- Phil Wadler.
arbitrarySizedBoundedIntegral :: (Bounded a, Integral a) => Gen a
arbitrarySizedBoundedIntegral =
  sized $ \s ->
    do let mn = minBound
           mx = maxBound `asTypeOf` mn
           bits n | n `quot` 2 == 0 = 0
                  | otherwise = 1 + bits (n `quot` 2)
           k  = 2^(s*(bits mn `max` bits mx `max` 40) `div` 100)
       n <- choose (toInteger mn `max` (-k), toInteger mx `min` k)
       return (fromInteger n `asTypeOf` mn)

instance Arbitrary Int8 where
  arbitrary = arbitrarySizedBoundedIntegral    
  shrink    = shrinkIntegral

instance Arbitrary Int16 where
  arbitrary = arbitrarySizedBoundedIntegral
  shrink    = shrinkIntegral

instance Arbitrary Int32 where
  arbitrary = arbitrarySizedBoundedIntegral
  shrink    = shrinkIntegral

instance Arbitrary Int64 where
  arbitrary = arbitrarySizedBoundedIntegral
  shrink    = shrinkIntegral

instance Arbitrary Word where
  arbitrary = arbitrarySizedBoundedIntegral
  shrink    = shrinkIntegral

instance Arbitrary Word8 where
  arbitrary = arbitrarySizedBoundedIntegral
  shrink    = shrinkIntegral

instance Arbitrary Word16 where
  arbitrary = arbitrarySizedBoundedIntegral
  shrink    = shrinkIntegral

instance Arbitrary Word32 where
  arbitrary = arbitrarySizedBoundedIntegral
  shrink    = shrinkIntegral

instance Arbitrary Word64 where
  arbitrary = arbitrarySizedBoundedIntegral
  shrink    = shrinkIntegral

instance CoArbitrary Int8 where
  coarbitrary = coarbitraryIntegral

instance CoArbitrary Int16 where
  coarbitrary = coarbitraryIntegral

instance CoArbitrary Int32 where
  coarbitrary = coarbitraryIntegral

instance CoArbitrary Int64 where
  coarbitrary = coarbitraryIntegral

instance CoArbitrary Word where
  coarbitrary = coarbitraryIntegral

instance CoArbitrary Word8 where
  coarbitrary = coarbitraryIntegral

instance CoArbitrary Word16 where
  coarbitrary = coarbitraryIntegral

instance CoArbitrary Word32 where
  coarbitrary = coarbitraryIntegral

instance CoArbitrary Word64 where
  coarbitrary = coarbitraryIntegral

#endif