Miscellaneous.hs

{-# LANGUAGE CPP                        #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE StandaloneDeriving         #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
{-|
Module:      Instances.Miscellaneous
Copyright:   (C) 2014-2017 Ryan Scott
License:     BSD-style (see the file LICENSE)
Maintainer:  Ryan Scott
Stability:   Provisional
Portability: GHC

Provides miscellaneous 'Arbitrary' instances (taken from @text-show@).
-}
module Instances.Miscellaneous () where

#include "HsBaseConfig.h"

import Foreign.C.Types (CInt(..), CUIntPtr(..))
import Foreign.Ptr (Ptr, nullPtr, plusPtr)

import Generics.Deriving.Instances ()

import Instances.Utils.GenericArbitrary (genericArbitrary)

import Prelude ()
import Prelude.Compat

import System.Exit (ExitCode(..))
import System.IO (Handle, stdin, stdout, stderr)
#if defined(HTYPE_GID_T)
import System.Posix.Types (CGid(..))
#endif
#if defined(HTYPE_UID_T)
import System.Posix.Types (CUid(..))
#endif

import Test.QuickCheck (Arbitrary(..), oneof)


instance Arbitrary ExitCode where
    arbitrary = genericArbitrary

instance Arbitrary Handle where
    arbitrary = oneof $ map pure [stdin, stdout, stderr]

instance Arbitrary (Ptr a) where
    arbitrary = plusPtr nullPtr <$> arbitrary

deriving instance Arbitrary CInt
deriving instance Arbitrary CUIntPtr

#if defined(HTYPE_GID_T)
deriving instance Arbitrary CGid
#endif

#if defined(HTYPE_UID_T)
deriving instance Arbitrary CUid
#endif