QuickCheck-GenT 0.1.1 → 0.1.2

raw patch · 2 files changed

+62/−31 lines, 2 files

Files

• QuickCheck-GenT.cabal +1/−1
• src/QuickCheck/GenT.hs +61/−30

@@ -1,7 +1,7 @@ name:   QuickCheck-GenT version:-  0.1.1+  0.1.2 synopsis:   A GenT monad transformer for QuickCheck library. description:

@@ -1,6 +1,6 @@ -- |--- Most of the code is borrowed from the following mailing list discussion:--- http://haskell.1045720.n5.nabble.com/darcs-patch-GenT-monad-transformer-variant-of-Gen-QuickCheck-2-td3172136.html+-- Most of the code is borrowed from +-- <http://haskell.1045720.n5.nabble.com/darcs-patch-GenT-monad-transformer-variant-of-Gen-QuickCheck-2-td3172136.html a mailing list discussion>. -- Therefor, credits go to Paul Johnson and Felix Martini. module QuickCheck.GenT where @@ -86,16 +86,39 @@   try k n = do x <- resize (2*k+n) gen                if p x then return (Just x) else try (k+1) (n-1) +-- | Generates a list of random length. The maximum length depends on the+-- size parameter.+listOf :: MonadGen m => m a -> m [a]+listOf gen = sized $ \n ->+  do k <- choose (0,n)+     vectorOf k gen++-- | Generates a non-empty list of random length. The maximum length+-- depends on the size parameter.+listOf1 :: MonadGen m => m a -> m [a]+listOf1 gen = sized $ \n ->+  do k <- choose (1,1 `max` n)+     vectorOf k gen++-- | Generates a list of the given length.+vectorOf :: MonadGen m => Int -> m a -> m [a]+vectorOf k gen = sequence [ gen | _ <- [1..k] ]+++-- * Partial functions+-------------------------+ -- | Randomly uses one of the given generators. The input list -- must be non-empty. oneof :: MonadGen m => [m a] -> m a-oneof [] = error "QuickCheck.oneof used with empty list"-oneof gs = choose (0,length gs - 1) >>= (gs !!)+oneof = +  fmap (fromMaybe (error "QuickCheck.GenT.oneof used with empty list")) .+  oneofMay  -- | Chooses one of the given generators, with a weighted random distribution. -- The input list must be non-empty. frequency :: MonadGen m => [(Int, m a)] -> m a-frequency [] = error "QuickCheck.frequency used with empty list"+frequency [] = error "QuickCheck.GenT.frequency used with empty list" frequency xs0 = choose (1, tot) >>= (`pick` xs0)  where   tot = sum (map fst xs0)@@ -103,41 +126,49 @@   pick n ((k,x):xs)     | n <= k    = x     | otherwise = pick (n-k) xs-  pick _ _  = error "QuickCheck.pick used with empty list"+  pick _ _  = error "QuickCheck.GenT.pick used with empty list"  -- | Generates one of the given values. The input list must be non-empty. elements :: MonadGen m => [a] -> m a-elements [] = error "QuickCheck.elements used with empty list"-elements xs = (xs !!) `fmap` choose (0, length xs - 1)+elements = +  fmap (fromMaybe (error "QuickCheck.GenT.elements used with empty list")) . +  elementsMay  -- | Takes a list of elements of increasing size, and chooses -- among an initial segment of the list. The size of this initial -- segment increases with the size parameter. -- The input list must be non-empty. growingElements :: MonadGen m => [a] -> m a-growingElements [] = error "QuickCheck.growingElements used with empty list"-growingElements xs = sized $ \n -> elements (take (1 `max` size n) xs)-  where-   k      = length xs-   mx     = 100-   log'   = round . log . fromIntegral-   size n = (log' n + 1) * k `div` log' mx+growingElements =+  fmap (fromMaybe (error "QuickCheck.GenT.growingElements used with empty list")) .+  growingElementsMay --- | Generates a list of random length. The maximum length depends on the--- size parameter.-listOf :: MonadGen m => m a -> m [a]-listOf gen = sized $ \n ->-  do k <- choose (0,n)-     vectorOf k gen --- | Generates a non-empty list of random length. The maximum length--- depends on the size parameter.-listOf1 :: MonadGen m => m a -> m [a]-listOf1 gen = sized $ \n ->-  do k <- choose (1,1 `max` n)-     vectorOf k gen+-- * Non-partial functions resulting in Maybe+------------------------- --- | Generates a list of the given length.-vectorOf :: MonadGen m => Int -> m a -> m [a]-vectorOf k gen = sequence [ gen | _ <- [1..k] ]+-- | +-- Randomly uses one of the given generators.+oneofMay :: MonadGen m => [m a] -> m (Maybe a)+oneofMay = \case+  [] -> return Nothing+  l -> fmap Just $ choose (0, length l - 1) >>= (l !!) +-- | Generates one of the given values. +elementsMay :: MonadGen m => [a] -> m (Maybe a)+elementsMay = \case+  [] -> return Nothing+  l -> Just . (l !!) <$> choose (0, length l - 1)++-- | Takes a list of elements of increasing size, and chooses+-- among an initial segment of the list. The size of this initial+-- segment increases with the size parameter.+growingElementsMay :: MonadGen m => [a] -> m (Maybe a)+growingElementsMay = \case+  [] -> return Nothing+  xs -> fmap Just $ sized $ \n -> elements (take (1 `max` size n) xs)+    where+      k = length xs+      mx = 100+      log' = round . log . fromIntegral+      size n = (log' n + 1) * k `div` log' mx