{-# OPTIONS_HADDOCK not-home #-}
{-# LANGUAGE ApplicativeDo #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DeriveFoldable #-}
{-# LANGUAGE DeriveFunctor #-}
{-# LANGUAGE DeriveTraversable #-}
{-# LANGUAGE DoAndIfThenElse #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE StandaloneDeriving #-}
{-# LANGUAGE TupleSections #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE TypeOperators #-}
{-# LANGUAGE UndecidableInstances #-} -- MonadBase
#if __GLASGOW_HASKELL__ >= 806
{-# LANGUAGE DerivingVia #-}
#endif

module Hedgehog.Internal.Gen (
  -- * Transformer
    Gen
  , GenT(..)
  , MonadGen(..)

  -- * Combinators
  , generalize

  -- ** Shrinking
  , shrink
  , prune

  -- ** Size
  , small
  , scale
  , resize
  , sized

  -- ** Integral
  , integral
  , integral_

  , int
  , int8
  , int16
  , int32
  , int64

  , word
  , word8
  , word16
  , word32
  , word64

  -- ** Floating-point
  , realFloat
  , realFrac_
  , float
  , double

  -- ** Enumeration
  , enum
  , enumBounded
  , bool
  , bool_

  -- ** Characters
  , binit
  , octit
  , digit
  , hexit
  , lower
  , upper
  , alpha
  , alphaNum
  , ascii
  , latin1
  , unicode
  , unicodeAll

  -- ** Strings
  , string
  , text
  , utf8
  , bytes

  -- ** Choice
  , constant
  , element
  , element_
  , choice
  , frequency
  , recursive

  -- ** Conditional
  , discard
  , ensure
  , filter
  , mapMaybe
  , filterT
  , mapMaybeT
  , just
  , justT

  -- ** Collections
  , maybe
  , either
  , either_
  , list
  , seq
  , nonEmpty
  , set
  , map

  -- ** Subterms
  , freeze
  , subterm
  , subtermM
  , subterm2
  , subtermM2
  , subterm3
  , subtermM3

  -- ** Combinations & Permutations
  , subsequence
  , subset
  , shuffle
  , shuffleSeq

  -- * Sampling Generators
  , sample
  , print
  , printTree
  , printWith
  , printTreeWith
  , renderTree

  -- * Internal
  -- $internal

  -- ** Transfomer
  , runGenT
  , evalGen
  , evalGenT
  , mapGenT
  , generate
  , toTree
  , toTreeMaybeT
  , fromTree
  , fromTreeT
  , fromTreeMaybeT
  , runDiscardEffect
  , runDiscardEffectT

  -- ** Size
  , golden

  -- ** Shrinking
  , atLeast

  -- ** Characters
  , isSurrogate
  , isNoncharacter

  -- ** Subterms
  , Vec(..)
  , Nat(..)
  , subtermMVec
  ) where

import           Control.Applicative (Alternative(..),liftA2)
import           Control.Monad (MonadPlus(..), filterM, guard, replicateM, join)
import           Control.Monad.Base (MonadBase(..))
import           Control.Monad.Trans.Control (MonadBaseControl(..))
import           Control.Monad.Catch (MonadThrow(..), MonadCatch(..))
import           Control.Monad.Error.Class (MonadError(..))
import           Control.Monad.IO.Class (MonadIO(..))
import           Control.Monad.Morph (MFunctor(..), MMonad(..))
import qualified Control.Monad.Morph as Morph
import           Control.Monad.Primitive (PrimMonad(..))
import           Control.Monad.Reader.Class (MonadReader(..))
import           Control.Monad.State.Class (MonadState(..))
import           Control.Monad.Trans.Class (MonadTrans(..))
import           Control.Monad.Trans.Except (ExceptT(..))
import           Control.Monad.Trans.Identity (IdentityT(..))
import           Control.Monad.Trans.Maybe (MaybeT(..))
import           Control.Monad.Trans.Reader (ReaderT(..))
import           Control.Monad.Trans.Resource (MonadResource(..))
import qualified Control.Monad.Trans.State.Lazy as Lazy
import qualified Control.Monad.Trans.State.Strict as Strict
import qualified Control.Monad.Trans.Writer.Lazy as Lazy
import qualified Control.Monad.Trans.Writer.Strict as Strict
import           Control.Monad.Writer.Class (MonadWriter(..))
import           Control.Monad.Zip (MonadZip(..))

import           Data.Bifunctor (first)
import           Data.ByteString (ByteString)
import qualified Data.ByteString as ByteString
import qualified Data.Char as Char
import           Data.Foldable (for_, toList)
import           Data.Functor.Identity (Identity(..))
import           Data.Int (Int8, Int16, Int32, Int64)
import           Data.Kind (Type)
import           Data.List.NonEmpty (NonEmpty)
import qualified Data.List.NonEmpty as NonEmpty
import           Data.Map (Map)
import qualified Data.Map as Map
import qualified Data.Maybe as Maybe
import qualified Data.Semigroup as Semigroup
import           Data.Sequence (Seq)
import qualified Data.Sequence as Seq
import           Data.Set (Set)
import qualified Data.Set as Set
import           Data.Text (Text)
import qualified Data.Text as Text
import qualified Data.Text.Encoding as Text
import           Data.Word (Word8, Word16, Word32, Word64)

import           Hedgehog.Internal.Distributive (MonadTransDistributive(..))
import           Hedgehog.Internal.Prelude hiding (either, maybe, seq)
import           Hedgehog.Internal.Seed (Seed)
import qualified Hedgehog.Internal.Seed as Seed
import qualified Hedgehog.Internal.Shrink as Shrink
import           Hedgehog.Internal.Tree (Tree, TreeT(..), NodeT(..))
import qualified Hedgehog.Internal.Tree as Tree
import           Hedgehog.Range (Size, Range)
import qualified Hedgehog.Range as Range

#if __GLASGOW_HASKELL__ < 808
import qualified Control.Monad.Fail as Fail
#endif
#if __GLASGOW_HASKELL__ < 806
import           Data.Coerce (coerce)
#endif

------------------------------------------------------------------------
-- Generator transformer

-- | Generator for random values of @a@.
--
type Gen =
  GenT Identity

-- | Monad transformer which can generate random values of @a@.
--
newtype GenT m a =
  GenT {
      forall (m :: * -> *) a.
GenT m a -> Size -> Seed -> TreeT (MaybeT m) a
unGenT :: Size -> Seed -> TreeT (MaybeT m) a
    }

-- | Runs a generator, producing its shrink tree.
--
runGenT :: Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT :: forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
seed (GenT Size -> Seed -> TreeT (MaybeT m) a
m) =
  Size -> Seed -> TreeT (MaybeT m) a
m Size
size Seed
seed

-- | Run a generator, producing its shrink tree.
--
--   'Nothing' means discarded, 'Just' means we have a value.
--
evalGen :: Size -> Seed -> Gen a -> Maybe (Tree a)
evalGen :: forall a. Size -> Seed -> Gen a -> Maybe (Tree a)
evalGen Size
size Seed
seed =
  forall a b. (a -> Maybe b) -> Tree a -> Maybe (Tree b)
Tree.mapMaybe forall a. a -> a
id forall b c a. (b -> c) -> (a -> b) -> a -> c
.
  forall (m :: * -> *) a.
Monad m =>
Size -> Seed -> GenT m a -> TreeT m (Maybe a)
evalGenT Size
size Seed
seed

-- | Runs a generator, producing its shrink tree.
--
evalGenT :: Monad m => Size -> Seed -> GenT m a -> TreeT m (Maybe a)
evalGenT :: forall (m :: * -> *) a.
Monad m =>
Size -> Seed -> GenT m a -> TreeT m (Maybe a)
evalGenT Size
size Seed
seed =
  forall (m :: * -> *) a.
Monad m =>
TreeT (MaybeT m) a -> TreeT m (Maybe a)
runDiscardEffectT forall b c a. (b -> c) -> (a -> b) -> a -> c
.
  forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
seed

-- | Map over a generator's shrink tree.
--
mapGenT :: (TreeT (MaybeT m) a -> TreeT (MaybeT n) b) -> GenT m a -> GenT n b
mapGenT :: forall (m :: * -> *) a (n :: * -> *) b.
(TreeT (MaybeT m) a -> TreeT (MaybeT n) b) -> GenT m a -> GenT n b
mapGenT TreeT (MaybeT m) a -> TreeT (MaybeT n) b
f GenT m a
gen =
  forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
size Seed
seed ->
    TreeT (MaybeT m) a -> TreeT (MaybeT n) b
f (forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
seed GenT m a
gen)

-- | Lift a predefined shrink tree in to a generator, ignoring the seed and the
--   size.
--
fromTree :: MonadGen m => Tree a -> m a
fromTree :: forall (m :: * -> *) a. MonadGen m => Tree a -> m a
fromTree =
  forall (m :: * -> *) a. MonadGen m => TreeT (GenBase m) a -> m a
fromTreeT forall b c a. (b -> c) -> (a -> b) -> a -> c
.
  forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist (forall (m :: * -> *) a. Monad m => Identity a -> m a
Morph.generalize)

-- | Lift a predefined shrink tree in to a generator, ignoring the seed and the
--   size.
--
fromTreeT :: MonadGen m => TreeT (GenBase m) a -> m a
fromTreeT :: forall (m :: * -> *) a. MonadGen m => TreeT (GenBase m) a -> m a
fromTreeT TreeT (GenBase m) a
x =
  forall (m :: * -> *) a.
MonadGen m =>
TreeT (MaybeT (GenBase m)) a -> m a
fromTreeMaybeT forall a b. (a -> b) -> a -> b
$
    forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist (forall (m :: * -> *) a. m (Maybe a) -> MaybeT m a
MaybeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall a. a -> Maybe a
Just) TreeT (GenBase m) a
x

-- | Lift a predefined shrink tree in to a generator, ignoring the seed and the
--   size.
--
fromTreeMaybeT :: MonadGen m => TreeT (MaybeT (GenBase m)) a -> m a
fromTreeMaybeT :: forall (m :: * -> *) a.
MonadGen m =>
TreeT (MaybeT (GenBase m)) a -> m a
fromTreeMaybeT TreeT (MaybeT (GenBase m)) a
x =
  forall (m :: * -> *) a. MonadGen m => GenT (GenBase m) a -> m a
fromGenT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
_ Seed
_ ->
    TreeT (MaybeT (GenBase m)) a
x

-- | Observe a generator's shrink tree.
--
toTree :: forall m a. (MonadGen m, GenBase m ~ Identity) => m a -> m (Tree a)
toTree :: forall (m :: * -> *) a.
(MonadGen m, GenBase m ~ Identity) =>
m a -> m (Tree a)
toTree =
  forall (m :: * -> *) (n :: * -> *) a b.
(MonadGen m, MonadGen n) =>
(GenT (GenBase m) a -> GenT (GenBase n) b) -> m a -> n b
withGenT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a (n :: * -> *) b.
(TreeT (MaybeT m) a -> TreeT (MaybeT n) b) -> GenT m a -> GenT n b
mapGenT (forall b a. b -> (a -> b) -> Maybe a -> b
Maybe.maybe forall (f :: * -> *) a. Alternative f => f a
empty forall (f :: * -> *) a. Applicative f => a -> f a
pure forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. TreeT (MaybeT Identity) a -> Maybe (Tree a)
runDiscardEffect)

-- | Lift a predefined shrink tree in to a generator, ignoring the seed and the
--   size.
--
toTreeMaybeT :: MonadGen m => m a -> m (TreeT (MaybeT (GenBase m)) a)
toTreeMaybeT :: forall (m :: * -> *) a.
MonadGen m =>
m a -> m (TreeT (MaybeT (GenBase m)) a)
toTreeMaybeT =
  forall (m :: * -> *) (n :: * -> *) a b.
(MonadGen m, MonadGen n) =>
(GenT (GenBase m) a -> GenT (GenBase n) b) -> m a -> n b
withGenT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a (n :: * -> *) b.
(TreeT (MaybeT m) a -> TreeT (MaybeT n) b) -> GenT m a -> GenT n b
mapGenT forall (f :: * -> *) a. Applicative f => a -> f a
pure

-- | Lazily run the discard effects through the tree and reify it a
--   @Maybe (Tree a)@.
--
--   'Nothing' means discarded, 'Just' means we have a value.
--
--   Discards in the child nodes of the tree are simply removed.
--
runDiscardEffect :: TreeT (MaybeT Identity) a -> Maybe (Tree a)
runDiscardEffect :: forall a. TreeT (MaybeT Identity) a -> Maybe (Tree a)
runDiscardEffect =
  forall a b. (a -> Maybe b) -> Tree a -> Maybe (Tree b)
Tree.mapMaybe forall a. a -> a
id forall b c a. (b -> c) -> (a -> b) -> a -> c
.
  forall (m :: * -> *) a.
Monad m =>
TreeT (MaybeT m) a -> TreeT m (Maybe a)
runDiscardEffectT

-- | Run the discard effects through the tree and reify them as 'Maybe' values
--   at the nodes.
--
--   'Nothing' means discarded, 'Just' means we have a value.
--
runDiscardEffectT :: Monad m => TreeT (MaybeT m) a -> TreeT m (Maybe a)
runDiscardEffectT :: forall (m :: * -> *) a.
Monad m =>
TreeT (MaybeT m) a -> TreeT m (Maybe a)
runDiscardEffectT =
  forall (m :: * -> *) a. MaybeT m a -> m (Maybe a)
runMaybeT forall b c a. (b -> c) -> (a -> b) -> a -> c
.
  forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT

-- | Lift a @Gen / GenT Identity@ in to a @Monad m => GenT m@
--
generalize :: Monad m => Gen a -> GenT m a
generalize :: forall (m :: * -> *) a. Monad m => Gen a -> GenT m a
generalize =
  forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. Monad m => Identity a -> m a
Morph.generalize

------------------------------------------------------------------------
-- MonadGen

-- | Class of monads which can generate input data for tests.
--
class (Monad m, Monad (GenBase m)) => MonadGen m where
  type GenBase m :: (Type -> Type)

  -- | Extract a 'GenT' from a  'MonadGen'.
  --
  toGenT :: m a -> GenT (GenBase m) a

  -- | Lift a 'GenT' in to a 'MonadGen'.
  --
  fromGenT :: GenT (GenBase m) a -> m a

-- | Transform a 'MonadGen' as a 'GenT'.
--
withGenT :: (MonadGen m, MonadGen n) => (GenT (GenBase m) a -> GenT (GenBase n) b) -> m a -> n b
withGenT :: forall (m :: * -> *) (n :: * -> *) a b.
(MonadGen m, MonadGen n) =>
(GenT (GenBase m) a -> GenT (GenBase n) b) -> m a -> n b
withGenT GenT (GenBase m) a -> GenT (GenBase n) b
f =
  forall (m :: * -> *) a. MonadGen m => GenT (GenBase m) a -> m a
fromGenT forall b c a. (b -> c) -> (a -> b) -> a -> c
. GenT (GenBase m) a -> GenT (GenBase n) b
f forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. MonadGen m => m a -> GenT (GenBase m) a
toGenT

instance Monad m => MonadGen (GenT m) where
  -- | The type of the transformer stack's base 'Monad'.
  --
  type GenBase (GenT m) =
    m

  -- | Convert a 'MonadGen' to a 'GenT'.
  --
  toGenT :: forall a. GenT m a -> GenT (GenBase (GenT m)) a
toGenT =
    forall a. a -> a
id

  -- | Convert a 'GenT' to a 'MonadGen'.
  --
  fromGenT :: forall a. GenT (GenBase (GenT m)) a -> GenT m a
fromGenT =
    forall a. a -> a
id

instance MonadGen m => MonadGen (IdentityT m) where
  type GenBase (IdentityT m) =
    IdentityT (GenBase m)

  toGenT :: forall a. IdentityT m a -> GenT (GenBase (IdentityT m)) a
toGenT =
    forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => m a -> GenT (GenBase m) a
toGenT

  fromGenT :: forall a. GenT (GenBase (IdentityT m)) a -> IdentityT m a
fromGenT =
    forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => GenT (GenBase m) a -> m a
fromGenT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT

instance MonadGen m => MonadGen (MaybeT m) where
  type GenBase (MaybeT m) =
    MaybeT (GenBase m)

  toGenT :: forall a. MaybeT m a -> GenT (GenBase (MaybeT m)) a
toGenT =
    forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => m a -> GenT (GenBase m) a
toGenT

  fromGenT :: forall a. GenT (GenBase (MaybeT m)) a -> MaybeT m a
fromGenT =
    forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => GenT (GenBase m) a -> m a
fromGenT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT

instance MonadGen m => MonadGen (ExceptT x m) where
  type GenBase (ExceptT x m) =
    ExceptT x (GenBase m)

  toGenT :: forall a. ExceptT x m a -> GenT (GenBase (ExceptT x m)) a
toGenT =
    forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => m a -> GenT (GenBase m) a
toGenT

  fromGenT :: forall a. GenT (GenBase (ExceptT x m)) a -> ExceptT x m a
fromGenT =
    forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => GenT (GenBase m) a -> m a
fromGenT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT

instance MonadGen m => MonadGen (ReaderT r m) where
  type GenBase (ReaderT r m) =
    ReaderT r (GenBase m)

  toGenT :: forall a. ReaderT r m a -> GenT (GenBase (ReaderT r m)) a
toGenT =
    forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => m a -> GenT (GenBase m) a
toGenT

  fromGenT :: forall a. GenT (GenBase (ReaderT r m)) a -> ReaderT r m a
fromGenT =
    forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => GenT (GenBase m) a -> m a
fromGenT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT

instance MonadGen m => MonadGen (Lazy.StateT r m) where
  type GenBase (Lazy.StateT r m) =
    Lazy.StateT r (GenBase m)

  toGenT :: forall a. StateT r m a -> GenT (GenBase (StateT r m)) a
toGenT =
    forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => m a -> GenT (GenBase m) a
toGenT

  fromGenT :: forall a. GenT (GenBase (StateT r m)) a -> StateT r m a
fromGenT =
    forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => GenT (GenBase m) a -> m a
fromGenT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT

instance MonadGen m => MonadGen (Strict.StateT r m) where
  type GenBase (Strict.StateT r m) =
    Strict.StateT r (GenBase m)

  toGenT :: forall a. StateT r m a -> GenT (GenBase (StateT r m)) a
toGenT =
    forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => m a -> GenT (GenBase m) a
toGenT

  fromGenT :: forall a. GenT (GenBase (StateT r m)) a -> StateT r m a
fromGenT =
    forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => GenT (GenBase m) a -> m a
fromGenT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT

instance (MonadGen m, Monoid w) => MonadGen (Lazy.WriterT w m) where
  type GenBase (Lazy.WriterT w m) =
    Lazy.WriterT w (GenBase m)

  toGenT :: forall a. WriterT w m a -> GenT (GenBase (WriterT w m)) a
toGenT =
    forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => m a -> GenT (GenBase m) a
toGenT

  fromGenT :: forall a. GenT (GenBase (WriterT w m)) a -> WriterT w m a
fromGenT =
    forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => GenT (GenBase m) a -> m a
fromGenT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT

instance (MonadGen m, Monoid w) => MonadGen (Strict.WriterT w m) where
  type GenBase (Strict.WriterT w m) =
    Strict.WriterT w (GenBase m)

  toGenT :: forall a. WriterT w m a -> GenT (GenBase (WriterT w m)) a
toGenT =
    forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => m a -> GenT (GenBase m) a
toGenT

  fromGenT :: forall a. GenT (GenBase (WriterT w m)) a -> WriterT w m a
fromGenT =
    forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. MonadGen m => GenT (GenBase m) a -> m a
fromGenT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT

------------------------------------------------------------------------
-- GenT instances

instance (Monad m, Semigroup a) => Semigroup (GenT m a) where
  <> :: GenT m a -> GenT m a -> GenT m a
(<>) =
    forall (f :: * -> *) a b c.
Applicative f =>
(a -> b -> c) -> f a -> f b -> f c
liftA2 forall a. Semigroup a => a -> a -> a
(Semigroup.<>)

instance (
  Monad m, Monoid a
#if !MIN_VERSION_base(4,11,0)
  , Semigroup a
#endif
         ) => Monoid (GenT m a) where
#if !MIN_VERSION_base(4,11,0)
  mappend = (Semigroup.<>)
#endif

  mempty :: GenT m a
mempty =
    forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Monoid a => a
mempty

instance Functor m => Functor (GenT m) where
  fmap :: forall a b. (a -> b) -> GenT m a -> GenT m b
fmap a -> b
f GenT m a
gen =
    forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
seed Seed
size ->
      forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap a -> b
f (forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
seed Seed
size GenT m a
gen)

--
-- implementation: parallel shrinking
--
instance Monad m => Applicative (GenT m) where
  pure :: forall a. a -> GenT m a
pure =
    forall (m :: * -> *) a.
MonadGen m =>
TreeT (MaybeT (GenBase m)) a -> m a
fromTreeMaybeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (f :: * -> *) a. Applicative f => a -> f a
pure

  <*> :: forall a b. GenT m (a -> b) -> GenT m a -> GenT m b
(<*>) GenT m (a -> b)
f GenT m a
m =
    forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \ Size
size Seed
seed ->
      case Seed -> (Seed, Seed)
Seed.split Seed
seed of
        (Seed
sf, Seed
sm) ->
          forall a b c. (a -> b -> c) -> (a, b) -> c
uncurry forall a b. (a -> b) -> a -> b
($) forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$>
            forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
sf GenT m (a -> b)
f forall (m :: * -> *) a b. MonadZip m => m a -> m b -> m (a, b)
`mzip`
            forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
sm GenT m a
m

--
-- implementation: satisfies law (ap = <*>)
--
--instance Monad m => Applicative (GenT m) where
--  pure =
--    fromTreeMaybeT . pure
--  (<*>) f m =
--    GenT $ \ size seed ->
--      case Seed.split seed of
--        (sf, sm) ->
--          runGenT size sf f <*>
--          runGenT size sm m

instance Monad m => Monad (GenT m) where
  return :: forall a. a -> GenT m a
return =
    forall (f :: * -> *) a. Applicative f => a -> f a
pure

  >>= :: forall a b. GenT m a -> (a -> GenT m b) -> GenT m b
(>>=) GenT m a
m a -> GenT m b
k =
    forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
size Seed
seed ->
      case Seed -> (Seed, Seed)
Seed.split Seed
seed of
        (Seed
sk, Seed
sm) ->
          forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
sk forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> GenT m b
k forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
=<<
          forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
sm GenT m a
m

#if __GLASGOW_HASKELL__ < 808
  fail =
    Fail.fail
#endif

instance Monad m => MonadFail (GenT m) where
  fail :: forall a. String -> GenT m a
fail =
    forall a. HasCallStack => String -> a
error

instance Monad m => Alternative (GenT m) where
  empty :: forall a. GenT m a
empty =
    forall (m :: * -> *) a. MonadPlus m => m a
mzero

  <|> :: forall a. GenT m a -> GenT m a -> GenT m a
(<|>) =
    forall (m :: * -> *) a. MonadPlus m => m a -> m a -> m a
mplus

instance Monad m => MonadPlus (GenT m) where
  mzero :: forall a. GenT m a
mzero =
    forall (m :: * -> *) a.
MonadGen m =>
TreeT (MaybeT (GenBase m)) a -> m a
fromTreeMaybeT forall (m :: * -> *) a. MonadPlus m => m a
mzero

  mplus :: forall a. GenT m a -> GenT m a -> GenT m a
mplus GenT m a
x GenT m a
y =
    forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
size Seed
seed ->
      case Seed -> (Seed, Seed)
Seed.split Seed
seed of
        (Seed
sx, Seed
sy) ->
          forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
sx GenT m a
x forall (m :: * -> *) a. MonadPlus m => m a -> m a -> m a
`mplus`
          forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
sy GenT m a
y

instance MonadTrans GenT where
  lift :: forall (m :: * -> *) a. Monad m => m a -> GenT m a
lift =
    forall (m :: * -> *) a.
MonadGen m =>
TreeT (MaybeT (GenBase m)) a -> m a
fromTreeMaybeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift

instance MFunctor GenT where
  hoist :: forall (m :: * -> *) (n :: * -> *) b.
Monad m =>
(forall a. m a -> n a) -> GenT m b -> GenT n b
hoist forall a. m a -> n a
f =
    forall (m :: * -> *) a (n :: * -> *) b.
(TreeT (MaybeT m) a -> TreeT (MaybeT n) b) -> GenT m a -> GenT n b
mapGenT (forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist (forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall a. m a -> n a
f))

embedMaybeT ::
     MonadTrans t
  => Monad n
  => Monad (t (MaybeT n))
  => (forall a. m a -> t (MaybeT n) a)
  -> MaybeT m b
  -> t (MaybeT n) b
embedMaybeT :: forall (t :: (* -> *) -> * -> *) (n :: * -> *) (m :: * -> *) b.
(MonadTrans t, Monad n, Monad (t (MaybeT n))) =>
(forall a. m a -> t (MaybeT n) a) -> MaybeT m b -> t (MaybeT n) b
embedMaybeT forall a. m a -> t (MaybeT n) a
f MaybeT m b
m =
  forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. m (Maybe a) -> MaybeT m a
MaybeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (f :: * -> *) a. Applicative f => a -> f a
pure forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
=<< forall a. m a -> t (MaybeT n) a
f (forall (m :: * -> *) a. MaybeT m a -> m (Maybe a)
runMaybeT MaybeT m b
m)

embedTreeMaybeT ::
     Monad n
  => (forall a. m a -> TreeT (MaybeT n) a)
  -> TreeT (MaybeT m) b
  -> TreeT (MaybeT n) b
embedTreeMaybeT :: forall (n :: * -> *) (m :: * -> *) b.
Monad n =>
(forall a. m a -> TreeT (MaybeT n) a)
-> TreeT (MaybeT m) b -> TreeT (MaybeT n) b
embedTreeMaybeT forall a. m a -> TreeT (MaybeT n) a
f TreeT (MaybeT m) b
tree_ =
  forall (t :: (* -> *) -> * -> *) (n :: * -> *) (m :: * -> *) b.
(MMonad t, Monad n) =>
(forall a. m a -> t n a) -> t m b -> t n b
embed (forall (t :: (* -> *) -> * -> *) (n :: * -> *) (m :: * -> *) b.
(MonadTrans t, Monad n, Monad (t (MaybeT n))) =>
(forall a. m a -> t (MaybeT n) a) -> MaybeT m b -> t (MaybeT n) b
embedMaybeT forall a. m a -> TreeT (MaybeT n) a
f) TreeT (MaybeT m) b
tree_

embedGenT ::
     Monad n
  => (forall a. m a -> GenT n a)
  -> GenT m b
  -> GenT n b
embedGenT :: forall (n :: * -> *) (m :: * -> *) b.
Monad n =>
(forall a. m a -> GenT n a) -> GenT m b -> GenT n b
embedGenT forall a. m a -> GenT n a
f GenT m b
gen =
  forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
size Seed
seed ->
    case Seed -> (Seed, Seed)
Seed.split Seed
seed of
      (Seed
sf, Seed
sg) ->
        (forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
sf forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. m a -> GenT n a
f) forall (n :: * -> *) (m :: * -> *) b.
Monad n =>
(forall a. m a -> TreeT (MaybeT n) a)
-> TreeT (MaybeT m) b -> TreeT (MaybeT n) b
`embedTreeMaybeT`
        (forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
sg GenT m b
gen)

instance MMonad GenT where
  embed :: forall (n :: * -> *) (m :: * -> *) b.
Monad n =>
(forall a. m a -> GenT n a) -> GenT m b -> GenT n b
embed =
    forall (n :: * -> *) (m :: * -> *) b.
Monad n =>
(forall a. m a -> GenT n a) -> GenT m b -> GenT n b
embedGenT

distributeGenT :: Transformer t GenT m => GenT (t m) a -> t (GenT m) a
distributeGenT :: forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
Transformer t GenT m =>
GenT (t m) a -> t (GenT m) a
distributeGenT GenT (t m) a
x =
  forall (m :: * -> *) a. Monad m => m (m a) -> m a
join forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
size Seed
seed ->
    forall (f :: * -> *) a. Applicative f => a -> f a
pure forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a.
MonadGen m =>
TreeT (MaybeT (GenBase m)) a -> m a
fromTreeMaybeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (g :: (* -> *) -> * -> *) (f :: (* -> *) -> * -> *)
       (m :: * -> *) a.
(MonadTransDistributive g, Transformer f g m) =>
g (f m) a -> f (g m) a
distributeT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
seed GenT (t m) a
x

instance MonadTransDistributive GenT where
  type Transformer t GenT m = (
      Monad (t (GenT m))
    , Transformer t MaybeT m
    , Transformer t TreeT (MaybeT m)
    )

  distributeT :: forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
Transformer t GenT m =>
GenT (t m) a -> t (GenT m) a
distributeT =
    forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
Transformer t GenT m =>
GenT (t m) a -> t (GenT m) a
distributeGenT

instance PrimMonad m => PrimMonad (GenT m) where
  type PrimState (GenT m) =
    PrimState m

  primitive :: forall a.
(State# (PrimState (GenT m))
 -> (# State# (PrimState (GenT m)), a #))
-> GenT m a
primitive =
    forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a.
PrimMonad m =>
(State# (PrimState m) -> (# State# (PrimState m), a #)) -> m a
primitive

instance MonadIO m => MonadIO (GenT m) where
  liftIO :: forall a. IO a -> GenT m a
liftIO =
    forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO

instance MonadBase b m => MonadBase b (GenT m) where
  liftBase :: forall α. b α -> GenT m α
liftBase =
    forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (b :: * -> *) (m :: * -> *) α. MonadBase b m => b α -> m α
liftBase

#if __GLASGOW_HASKELL__ >= 806
deriving via (ReaderT Size (ReaderT Seed (TreeT (MaybeT m))))
  instance MonadBaseControl b m => MonadBaseControl b (GenT m)
#else
instance MonadBaseControl b m => MonadBaseControl b (GenT m) where
  type StM (GenT m) a = StM (GloopT m) a
  liftBaseWith g = gloopToGen $ liftBaseWith $ \q -> g (\gen -> q (genToGloop gen))
  restoreM = gloopToGen . restoreM

type GloopT m = ReaderT Size (ReaderT Seed (TreeT (MaybeT m)))

gloopToGen :: GloopT m a -> GenT m a
gloopToGen = coerce

genToGloop :: GenT m a -> GloopT m a
genToGloop = coerce
#endif

instance MonadThrow m => MonadThrow (GenT m) where
  throwM :: forall e a. Exception e => e -> GenT m a
throwM =
    forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) e a. (MonadThrow m, Exception e) => e -> m a
throwM

instance MonadCatch m => MonadCatch (GenT m) where
  catch :: forall e a. Exception e => GenT m a -> (e -> GenT m a) -> GenT m a
catch GenT m a
m e -> GenT m a
onErr =
    forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
size Seed
seed ->
      case Seed -> (Seed, Seed)
Seed.split Seed
seed of
        (Seed
sm, Seed
se) ->
          (forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
sm GenT m a
m) forall (m :: * -> *) e a.
(MonadCatch m, Exception e) =>
m a -> (e -> m a) -> m a
`catch`
          (forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
se forall b c a. (b -> c) -> (a -> b) -> a -> c
. e -> GenT m a
onErr)

instance MonadReader r m => MonadReader r (GenT m) where
  ask :: GenT m r
ask =
    forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall r (m :: * -> *). MonadReader r m => m r
ask
  local :: forall a. (r -> r) -> GenT m a -> GenT m a
local r -> r
f GenT m a
m =
    forall (m :: * -> *) a (n :: * -> *) b.
(TreeT (MaybeT m) a -> TreeT (MaybeT n) b) -> GenT m a -> GenT n b
mapGenT (forall r (m :: * -> *) a. MonadReader r m => (r -> r) -> m a -> m a
local r -> r
f) GenT m a
m

instance MonadState s m => MonadState s (GenT m) where
  get :: GenT m s
get =
    forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall s (m :: * -> *). MonadState s m => m s
get
  put :: s -> GenT m ()
put =
    forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall s (m :: * -> *). MonadState s m => s -> m ()
put
  state :: forall a. (s -> (a, s)) -> GenT m a
state =
    forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall s (m :: * -> *) a. MonadState s m => (s -> (a, s)) -> m a
state

instance MonadWriter w m => MonadWriter w (GenT m) where
  writer :: forall a. (a, w) -> GenT m a
writer =
    forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall w (m :: * -> *) a. MonadWriter w m => (a, w) -> m a
writer
  tell :: w -> GenT m ()
tell =
    forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall w (m :: * -> *). MonadWriter w m => w -> m ()
tell
  listen :: forall a. GenT m a -> GenT m (a, w)
listen GenT m a
m =
    forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
size Seed
seed ->
      forall w (m :: * -> *) a. MonadWriter w m => m a -> m (a, w)
listen forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
seed GenT m a
m
  pass :: forall a. GenT m (a, w -> w) -> GenT m a
pass GenT m (a, w -> w)
m =
    forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
size Seed
seed ->
      forall w (m :: * -> *) a. MonadWriter w m => m (a, w -> w) -> m a
pass forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
seed GenT m (a, w -> w)
m

instance MonadError e m => MonadError e (GenT m) where
  throwError :: forall a. e -> GenT m a
throwError =
    forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall e (m :: * -> *) a. MonadError e m => e -> m a
throwError
  catchError :: forall a. GenT m a -> (e -> GenT m a) -> GenT m a
catchError GenT m a
m e -> GenT m a
onErr =
    forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
size Seed
seed ->
      case Seed -> (Seed, Seed)
Seed.split Seed
seed of
        (Seed
sm, Seed
se) ->
          (forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
sm GenT m a
m) forall e (m :: * -> *) a.
MonadError e m =>
m a -> (e -> m a) -> m a
`catchError`
          (forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
se forall b c a. (b -> c) -> (a -> b) -> a -> c
. e -> GenT m a
onErr)

instance MonadResource m => MonadResource (GenT m) where
  liftResourceT :: forall a. ResourceT IO a -> GenT m a
liftResourceT =
    forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. MonadResource m => ResourceT IO a -> m a
liftResourceT

------------------------------------------------------------------------
-- Combinators

-- | Generate a value with no shrinks from a 'Size' and a 'Seed'.
--
generate :: MonadGen m => (Size -> Seed -> a) -> m a
generate :: forall (m :: * -> *) a. MonadGen m => (Size -> Seed -> a) -> m a
generate Size -> Seed -> a
f =
  forall (m :: * -> *) a. MonadGen m => GenT (GenBase m) a -> m a
fromGenT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
size Seed
seed ->
    forall (f :: * -> *) a. Applicative f => a -> f a
pure (Size -> Seed -> a
f Size
size Seed
seed)

------------------------------------------------------------------------
-- Combinators - Shrinking

-- | Apply a shrinking function to a generator.
--
--   This will give the generator additional shrinking options, while keeping
--   the existing shrinks intact.
--
shrink :: MonadGen m => (a -> [a]) -> m a -> m a
shrink :: forall (m :: * -> *) a. MonadGen m => (a -> [a]) -> m a -> m a
shrink a -> [a]
f =
  forall (m :: * -> *) (n :: * -> *) a b.
(MonadGen m, MonadGen n) =>
(GenT (GenBase m) a -> GenT (GenBase n) b) -> m a -> n b
withGenT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a (n :: * -> *) b.
(TreeT (MaybeT m) a -> TreeT (MaybeT n) b) -> GenT m a -> GenT n b
mapGenT (forall (m :: * -> *) a.
Monad m =>
(a -> [a]) -> TreeT m a -> TreeT m a
Tree.expand a -> [a]
f)

-- | Throw away a generator's shrink tree.
--
prune :: MonadGen m => m a -> m a
prune :: forall (m :: * -> *) a. MonadGen m => m a -> m a
prune =
  forall (m :: * -> *) (n :: * -> *) a b.
(MonadGen m, MonadGen n) =>
(GenT (GenBase m) a -> GenT (GenBase n) b) -> m a -> n b
withGenT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a (n :: * -> *) b.
(TreeT (MaybeT m) a -> TreeT (MaybeT n) b) -> GenT m a -> GenT n b
mapGenT (forall (m :: * -> *) a. Monad m => Int -> TreeT m a -> TreeT m a
Tree.prune Int
0)

------------------------------------------------------------------------
-- Combinators - Size

-- | Construct a generator that depends on the size parameter.
--
sized :: MonadGen m => (Size -> m a) -> m a
sized :: forall (m :: * -> *) a. MonadGen m => (Size -> m a) -> m a
sized Size -> m a
f = do
  Size -> m a
f forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
=<< forall (m :: * -> *) a. MonadGen m => (Size -> Seed -> a) -> m a
generate (\Size
size Seed
_ -> Size
size)

-- | Override the size parameter. Returns a generator which uses the given size
--   instead of the runtime-size parameter.
--
resize :: MonadGen m => Size -> m a -> m a
resize :: forall (m :: * -> *) a. MonadGen m => Size -> m a -> m a
resize Size
size m a
gen =
  forall (m :: * -> *) a. MonadGen m => (Size -> Size) -> m a -> m a
scale (forall a b. a -> b -> a
const Size
size) m a
gen

-- | Adjust the size parameter by transforming it with the given function.
--
scale :: MonadGen m => (Size -> Size) -> m a -> m a
scale :: forall (m :: * -> *) a. MonadGen m => (Size -> Size) -> m a -> m a
scale Size -> Size
f =
  forall (m :: * -> *) (n :: * -> *) a b.
(MonadGen m, MonadGen n) =>
(GenT (GenBase m) a -> GenT (GenBase n) b) -> m a -> n b
withGenT forall a b. (a -> b) -> a -> b
$ \GenT (GenBase m) a
gen ->
    forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
size0 Seed
seed ->
      let
        size :: Size
size =
          Size -> Size
f Size
size0
      in
        if Size
size forall a. Ord a => a -> a -> Bool
< Size
0 then
          forall a. HasCallStack => String -> a
error String
"Hedgehog.Gen.scale: negative size"
        else
          forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
seed GenT (GenBase m) a
gen

-- | Make a generator smaller by scaling its size parameter.
--
small :: MonadGen m => m a -> m a
small :: forall (m :: * -> *) a. MonadGen m => m a -> m a
small =
  forall (m :: * -> *) a. MonadGen m => (Size -> Size) -> m a -> m a
scale Size -> Size
golden

-- | Scale a size using the golden ratio.
--
--   > golden x = x / φ
--   > golden x = x / 1.61803..
--
golden :: Size -> Size
golden :: Size -> Size
golden Size
x =
  forall a b. (RealFrac a, Integral b) => a -> b
round (forall a b. (Integral a, Num b) => a -> b
fromIntegral Size
x forall a. Num a => a -> a -> a
* Double
0.61803398875 :: Double)

------------------------------------------------------------------------
-- Combinators - Integral

-- | Generates a random integral number in the given @[inclusive,inclusive]@ range.
--
--   When the generator tries to shrink, it will shrink towards the
--   'Range.origin' of the specified 'Range'.
--
--   For example, the following generator will produce a number between @1970@
--   and @2100@, but will shrink towards @2000@:
--
-- @
-- integral (Range.'Range.constantFrom' 2000 1970 2100) :: 'Gen' 'Int'
-- @
--
--   Some sample outputs from this generator might look like:
--
--   > === Outcome ===
--   > 1973
--   > === Shrinks ===
--   > 2000
--   > 1987
--   > 1980
--   > 1976
--   > 1974
--
--   > === Outcome ===
--   > 2061
--   > === Shrinks ===
--   > 2000
--   > 2031
--   > 2046
--   > 2054
--   > 2058
--   > 2060
--
integral :: forall m a. (MonadGen m, Integral a) => Range a -> m a
integral :: forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral Range a
range =
  -- https://github.com/hedgehogqa/haskell-hedgehog/pull/413/files
  let
    origin_ :: a
origin_ =
      forall a. Range a -> a
Range.origin Range a
range

    binarySearchTree :: a -> a -> TreeT Identity a
binarySearchTree a
bottom a
top =
      forall a. NodeT Identity a -> Tree a
Tree.Tree forall a b. (a -> b) -> a -> b
$
        let
          shrinks :: [a]
shrinks =
            forall a. Integral a => a -> a -> [a]
Shrink.towards a
bottom a
top
          children :: [TreeT Identity a]
children =
            forall a b c. (a -> b -> c) -> [a] -> [b] -> [c]
zipWith a -> a -> TreeT Identity a
binarySearchTree [a]
shrinks (forall a. Int -> [a] -> [a]
drop Int
1 [a]
shrinks)
        in
          forall (m :: * -> *) a. a -> [TreeT m a] -> NodeT m a
Tree.NodeT a
top [TreeT Identity a]
children

    createTree :: a -> TreeT (MaybeT (GenBase m)) a
createTree a
root =
      if a
root forall a. Eq a => a -> a -> Bool
== a
origin_ then
        forall (f :: * -> *) a. Applicative f => a -> f a
pure a
root
      else
        forall {k} (t :: (* -> *) -> k -> *) (m :: * -> *) (n :: * -> *)
       (b :: k).
(MFunctor t, Monad m) =>
(forall a. m a -> n a) -> t m b -> t n b
hoist forall (m :: * -> *) a. Monad m => Identity a -> m a
Morph.generalize forall a b. (a -> b) -> a -> b
$
          forall (m :: * -> *) a. Monad m => a -> TreeT m a -> TreeT m a
Tree.consChild a
origin_ forall a b. (a -> b) -> a -> b
$
            forall {a}. Integral a => a -> a -> TreeT Identity a
binarySearchTree a
origin_ a
root

  in
    forall (m :: * -> *) a. MonadGen m => GenT (GenBase m) a -> m a
fromGenT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
size Seed
seed ->
      a -> TreeT (MaybeT (GenBase m)) a
createTree forall a b. (a -> b) -> a -> b
$ forall a c. (Integral a, Num c) => Range a -> Size -> Seed -> c
integralHelper Range a
range Size
size Seed
seed

-- | Generates a random integral number in the [inclusive,inclusive] range.
--
--   /This generator does not shrink./
--
integral_ :: (MonadGen m, Integral a) => Range a -> m a
integral_ :: forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral_ =
  forall (m :: * -> *) a. MonadGen m => (Size -> Seed -> a) -> m a
generate forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a c. (Integral a, Num c) => Range a -> Size -> Seed -> c
integralHelper


-- | Generates a random integral value from a range.
integralHelper :: (Integral a, Num c) => Range a -> Size -> Seed -> c
integralHelper :: forall a c. (Integral a, Num c) => Range a -> Size -> Seed -> c
integralHelper Range a
range Size
size Seed
seed =
  let
    (a
x, a
y) =
      forall a. Size -> Range a -> (a, a)
Range.bounds Size
size Range a
range
  in
    forall a. Num a => Integer -> a
fromInteger forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a b. (a, b) -> a
fst forall a b. (a -> b) -> a -> b
$
      Integer -> Integer -> Seed -> (Integer, Seed)
Seed.nextInteger (forall a. Integral a => a -> Integer
toInteger a
x) (forall a. Integral a => a -> Integer
toInteger a
y) Seed
seed


-- | Generates a random machine integer in the given @[inclusive,inclusive]@ range.
--
--   /This is a specialization of 'integral', offered for convenience./
--
int :: MonadGen m => Range Int -> m Int
int :: forall (m :: * -> *). MonadGen m => Range Int -> m Int
int =
  forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral

-- | Generates a random 8-bit integer in the given @[inclusive,inclusive]@ range.
--
--   /This is a specialization of 'integral', offered for convenience./
--
int8 :: MonadGen m => Range Int8 -> m Int8
int8 :: forall (m :: * -> *). MonadGen m => Range Int8 -> m Int8
int8 =
  forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral

-- | Generates a random 16-bit integer in the given @[inclusive,inclusive]@ range.
--
--   /This is a specialization of 'integral', offered for convenience./
--
int16 :: MonadGen m => Range Int16 -> m Int16
int16 :: forall (m :: * -> *). MonadGen m => Range Int16 -> m Int16
int16 =
  forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral

-- | Generates a random 32-bit integer in the given @[inclusive,inclusive]@ range.
--
--   /This is a specialization of 'integral', offered for convenience./
--
int32 :: MonadGen m => Range Int32 -> m Int32
int32 :: forall (m :: * -> *). MonadGen m => Range Int32 -> m Int32
int32 =
  forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral

-- | Generates a random 64-bit integer in the given @[inclusive,inclusive]@ range.
--
--   /This is a specialization of 'integral', offered for convenience./
--
int64 :: MonadGen m => Range Int64 -> m Int64
int64 :: forall (m :: * -> *). MonadGen m => Range Int64 -> m Int64
int64 =
  forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral

-- | Generates a random machine word in the given @[inclusive,inclusive]@ range.
--
--   /This is a specialization of 'integral', offered for convenience./
--
word :: MonadGen m => Range Word -> m Word
word :: forall (m :: * -> *). MonadGen m => Range Word -> m Word
word =
  forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral

-- | Generates a random byte in the given @[inclusive,inclusive]@ range.
--
--   /This is a specialization of 'integral', offered for convenience./
--
word8 :: MonadGen m => Range Word8 -> m Word8
word8 :: forall (m :: * -> *). MonadGen m => Range Word8 -> m Word8
word8 =
  forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral

-- | Generates a random 16-bit word in the given @[inclusive,inclusive]@ range.
--
--   /This is a specialization of 'integral', offered for convenience./
--
word16 :: MonadGen m => Range Word16 -> m Word16
word16 :: forall (m :: * -> *). MonadGen m => Range Word16 -> m Word16
word16 =
  forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral

-- | Generates a random 32-bit word in the given @[inclusive,inclusive]@ range.
--
--   /This is a specialization of 'integral', offered for convenience./
--
word32 :: MonadGen m => Range Word32 -> m Word32
word32 :: forall (m :: * -> *). MonadGen m => Range Word32 -> m Word32
word32 =
  forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral

-- | Generates a random 64-bit word in the given @[inclusive,inclusive]@ range.
--
--   /This is a specialization of 'integral', offered for convenience./
--
word64 :: MonadGen m => Range Word64 -> m Word64
word64 :: forall (m :: * -> *). MonadGen m => Range Word64 -> m Word64
word64 =
  forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral

------------------------------------------------------------------------
-- Combinators - Fractional / Floating-Point

-- | Generates a random floating-point number in the @[inclusive,exclusive)@ range.
--
--   /This generator works the same as 'integral', but for floating point numbers./
--
realFloat :: (MonadGen m, RealFloat a) => Range a -> m a
realFloat :: forall (m :: * -> *) a. (MonadGen m, RealFloat a) => Range a -> m a
realFloat Range a
range =
  forall (m :: * -> *) a. MonadGen m => (a -> [a]) -> m a -> m a
shrink (forall a. RealFloat a => a -> a -> [a]
Shrink.towardsFloat forall a b. (a -> b) -> a -> b
$ forall a. Range a -> a
Range.origin Range a
range) (forall (m :: * -> *) a. (MonadGen m, RealFrac a) => Range a -> m a
realFrac_ Range a
range)

-- | Generates a random fractional number in the [inclusive,exclusive) range.
--
--   /This generator does not shrink./
--
realFrac_ :: (MonadGen m, RealFrac a) => Range a -> m a
realFrac_ :: forall (m :: * -> *) a. (MonadGen m, RealFrac a) => Range a -> m a
realFrac_ Range a
range =
  forall (m :: * -> *) a. MonadGen m => (Size -> Seed -> a) -> m a
generate forall a b. (a -> b) -> a -> b
$ \Size
size Seed
seed ->
    let
      (a
x, a
y) =
        forall a. Size -> Range a -> (a, a)
Range.bounds Size
size Range a
range
    in
      forall a b. (Real a, Fractional b) => a -> b
realToFrac forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a b. (a, b) -> a
fst forall a b. (a -> b) -> a -> b
$
        Double -> Double -> Seed -> (Double, Seed)
Seed.nextDouble (forall a b. (Real a, Fractional b) => a -> b
realToFrac a
x) (forall a b. (Real a, Fractional b) => a -> b
realToFrac a
y) Seed
seed

-- | Generates a random floating-point number in the @[inclusive,exclusive)@ range.
--
--   /This is a specialization of 'realFloat', offered for convenience./
--
float :: MonadGen m => Range Float -> m Float
float :: forall (m :: * -> *). MonadGen m => Range Float -> m Float
float =
 forall (m :: * -> *) a. (MonadGen m, RealFloat a) => Range a -> m a
realFloat

-- | Generates a random floating-point number in the @[inclusive,exclusive)@ range.
--
--   /This is a specialization of 'realFloat', offered for convenience./
--
double :: MonadGen m => Range Double -> m Double
double :: forall (m :: * -> *). MonadGen m => Range Double -> m Double
double =
 forall (m :: * -> *) a. (MonadGen m, RealFloat a) => Range a -> m a
realFloat

------------------------------------------------------------------------
-- Combinators - Enumeration

-- | Generates an element from an enumeration.
--
--   This generator shrinks towards the first argument.
--
--   For example:
--
-- @
-- enum \'a' \'z' :: 'Gen' 'Char'
-- @
--
enum :: (MonadGen m, Enum a) => a -> a -> m a
enum :: forall (m :: * -> *) a. (MonadGen m, Enum a) => a -> a -> m a
enum a
lo a
hi =
  forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall a. Enum a => Int -> a
toEnum forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral forall a b. (a -> b) -> a -> b
$
    forall a. a -> a -> Range a
Range.constant (forall a. Enum a => a -> Int
fromEnum a
lo) (forall a. Enum a => a -> Int
fromEnum a
hi)

-- | Generates a random value from a bounded enumeration.
--
--   This generator shrinks towards 'minBound'.
--
--   For example:
--
-- @
-- enumBounded :: 'Gen' 'Bool'
-- @
--
--   /This is implemented in terms of the 'Enum' class, and thus may be/
--   /partial for integral types larger than 'Int', e.g. 'Word64'./
enumBounded :: (MonadGen m, Enum a, Bounded a) => m a
enumBounded :: forall (m :: * -> *) a. (MonadGen m, Enum a, Bounded a) => m a
enumBounded =
  forall (m :: * -> *) a. (MonadGen m, Enum a) => a -> a -> m a
enum forall a. Bounded a => a
minBound forall a. Bounded a => a
maxBound

-- | Generates a random boolean.
--
--   This generator shrinks to 'False'.
--
--   /This is a specialization of 'enumBounded', offered for convenience./
--
bool :: MonadGen m => m Bool
bool :: forall (m :: * -> *). MonadGen m => m Bool
bool =
  forall (m :: * -> *) a. (MonadGen m, Enum a, Bounded a) => m a
enumBounded

-- | Generates a random boolean.
--
--   /This generator does not shrink./
--
bool_ :: MonadGen m => m Bool
bool_ :: forall (m :: * -> *). MonadGen m => m Bool
bool_ =
  forall (m :: * -> *) a. MonadGen m => (Size -> Seed -> a) -> m a
generate forall a b. (a -> b) -> a -> b
$ \Size
_ Seed
seed ->
    (forall a. Eq a => a -> a -> Bool
/= Integer
0) forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a b. (a, b) -> a
fst forall a b. (a -> b) -> a -> b
$ Integer -> Integer -> Seed -> (Integer, Seed)
Seed.nextInteger Integer
0 Integer
1 Seed
seed

------------------------------------------------------------------------
-- Combinators - Characters

-- | Generates an ASCII binit: @'0'..'1'@
--
binit :: MonadGen m => m Char
binit :: forall (m :: * -> *). MonadGen m => m Char
binit =
  forall (m :: * -> *) a. (MonadGen m, Enum a) => a -> a -> m a
enum Char
'0' Char
'1'

-- | Generates an ASCII octit: @'0'..'7'@
--
octit :: MonadGen m => m Char
octit :: forall (m :: * -> *). MonadGen m => m Char
octit =
  forall (m :: * -> *) a. (MonadGen m, Enum a) => a -> a -> m a
enum Char
'0' Char
'7'

-- | Generates an ASCII digit: @'0'..'9'@
--
digit :: MonadGen m => m Char
digit :: forall (m :: * -> *). MonadGen m => m Char
digit =
  forall (m :: * -> *) a. (MonadGen m, Enum a) => a -> a -> m a
enum Char
'0' Char
'9'

-- | Generates an ASCII hexit: @'0'..'9', \'a\'..\'f\', \'A\'..\'F\'@
--
hexit :: MonadGen m => m Char
hexit :: forall (m :: * -> *). MonadGen m => m Char
hexit =
  -- FIXME optimize lookup, use a SmallArray or something.
  forall (m :: * -> *) a. MonadGen m => [a] -> m a
element String
"0123456789aAbBcCdDeEfF"

-- | Generates an ASCII lowercase letter: @\'a\'..\'z\'@
--
lower :: MonadGen m => m Char
lower :: forall (m :: * -> *). MonadGen m => m Char
lower =
  forall (m :: * -> *) a. (MonadGen m, Enum a) => a -> a -> m a
enum Char
'a' Char
'z'

-- | Generates an ASCII uppercase letter: @\'A\'..\'Z\'@
--
upper :: MonadGen m => m Char
upper :: forall (m :: * -> *). MonadGen m => m Char
upper =
  forall (m :: * -> *) a. (MonadGen m, Enum a) => a -> a -> m a
enum Char
'A' Char
'Z'

-- | Generates an ASCII letter: @\'a\'..\'z\', \'A\'..\'Z\'@
--
alpha :: MonadGen m => m Char
alpha :: forall (m :: * -> *). MonadGen m => m Char
alpha =
  -- FIXME optimize lookup, use a SmallArray or something.
  forall (m :: * -> *) a. MonadGen m => [a] -> m a
element String
"abcdefghiklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

-- | Generates an ASCII letter or digit: @\'a\'..\'z\', \'A\'..\'Z\', \'0\'..\'9\'@
--
alphaNum :: MonadGen m => m Char
alphaNum :: forall (m :: * -> *). MonadGen m => m Char
alphaNum =
  -- FIXME optimize lookup, use a SmallArray or something.
  forall (m :: * -> *) a. MonadGen m => [a] -> m a
element String
"abcdefghiklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"

-- | Generates an ASCII character: @'\0'..'\127'@
--
ascii :: MonadGen m => m Char
ascii :: forall (m :: * -> *). MonadGen m => m Char
ascii =
  forall (m :: * -> *) a. (MonadGen m, Enum a) => a -> a -> m a
enum Char
'\0' Char
'\127'

-- | Generates a Latin-1 character: @'\0'..'\255'@
--
latin1 :: MonadGen m => m Char
latin1 :: forall (m :: * -> *). MonadGen m => m Char
latin1 =
  forall (m :: * -> *) a. (MonadGen m, Enum a) => a -> a -> m a
enum Char
'\0' Char
'\255'

-- | Generates a Unicode character, excluding noncharacters and invalid standalone surrogates:
--   @'\0'..'\1114111' (excluding '\55296'..'\57343', '\65534', '\65535')@
--
unicode :: (MonadGen m) => m Char
unicode :: forall (m :: * -> *). MonadGen m => m Char
unicode =
  let
    s1 :: (Int, m Char)
s1 =
      (Int
55296, forall (m :: * -> *) a. (MonadGen m, Enum a) => a -> a -> m a
enum Char
'\0' Char
'\55295')
    s2 :: (Int, m Char)
s2 =
      (Int
8190, forall (m :: * -> *) a. (MonadGen m, Enum a) => a -> a -> m a
enum Char
'\57344' Char
'\65533')
    s3 :: (Int, m Char)
s3 =
      (Int
1048576, forall (m :: * -> *) a. (MonadGen m, Enum a) => a -> a -> m a
enum Char
'\65536' Char
'\1114111')
  in
    forall (m :: * -> *) a. MonadGen m => [(Int, m a)] -> m a
frequency [(Int, m Char)
s1, (Int, m Char)
s2, (Int, m Char)
s3]

-- | Generates a Unicode character, including noncharacters and invalid standalone surrogates:
--   @'\0'..'\1114111'@
--
unicodeAll :: MonadGen m => m Char
unicodeAll :: forall (m :: * -> *). MonadGen m => m Char
unicodeAll =
  forall (m :: * -> *) a. (MonadGen m, Enum a, Bounded a) => m a
enumBounded

-- | Check if a character is in the surrogate category.
--
isSurrogate :: Char -> Bool
isSurrogate :: Char -> Bool
isSurrogate Char
x =
  Char
x forall a. Ord a => a -> a -> Bool
>= Char
'\55296' Bool -> Bool -> Bool
&& Char
x forall a. Ord a => a -> a -> Bool
<= Char
'\57343'

-- | Check if a character is one of the noncharacters '\65534', '\65535'.
--
isNoncharacter :: Char -> Bool
isNoncharacter :: Char -> Bool
isNoncharacter Char
x =
  Char
x forall a. Eq a => a -> a -> Bool
== Char
'\65534' Bool -> Bool -> Bool
|| Char
x forall a. Eq a => a -> a -> Bool
== Char
'\65535'

------------------------------------------------------------------------
-- Combinators - Strings

-- | Generates a string using 'Range' to determine the length.
--
--   /This is a specialization of 'list', offered for convenience./
--
string :: MonadGen m => Range Int -> m Char -> m String
string :: forall (m :: * -> *). MonadGen m => Range Int -> m Char -> m String
string =
  forall (m :: * -> *) a. MonadGen m => Range Int -> m a -> m [a]
list

-- | Generates a string using 'Range' to determine the length.
--
text :: MonadGen m => Range Int -> m Char -> m Text
text :: forall (m :: * -> *). MonadGen m => Range Int -> m Char -> m Text
text Range Int
range =
  forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap String -> Text
Text.pack forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *). MonadGen m => Range Int -> m Char -> m String
string Range Int
range

-- | Generates a UTF-8 encoded string, using 'Range' to determine the length.
--
utf8 :: MonadGen m => Range Int -> m Char -> m ByteString
utf8 :: forall (m :: * -> *).
MonadGen m =>
Range Int -> m Char -> m ByteString
utf8 Range Int
range =
  forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap Text -> ByteString
Text.encodeUtf8 forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *). MonadGen m => Range Int -> m Char -> m Text
text Range Int
range

-- | Generates a random 'ByteString', using 'Range' to determine the
--   length.
--
bytes :: MonadGen m => Range Int -> m ByteString
bytes :: forall (m :: * -> *). MonadGen m => Range Int -> m ByteString
bytes Range Int
range =
  forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap [Word8] -> ByteString
ByteString.pack forall a b. (a -> b) -> a -> b
$
  forall (m :: * -> *) a. MonadGen m => [m a] -> m a
choice [
      forall (m :: * -> *) a. MonadGen m => Range Int -> m a -> m [a]
list Range Int
range forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *). MonadGen m => Range Word8 -> m Word8
word8 forall a b. (a -> b) -> a -> b
$
        forall a. a -> a -> Range a
Range.constant
          (forall a b. (Integral a, Num b) => a -> b
fromIntegral forall a b. (a -> b) -> a -> b
$ Char -> Int
Char.ord Char
'a')
          (forall a b. (Integral a, Num b) => a -> b
fromIntegral forall a b. (a -> b) -> a -> b
$ Char -> Int
Char.ord Char
'z')

    , forall (m :: * -> *) a. MonadGen m => Range Int -> m a -> m [a]
list Range Int
range forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *). MonadGen m => Range Word8 -> m Word8
word8 forall a b. (a -> b) -> a -> b
$
        forall a. a -> a -> Range a
Range.constant forall a. Bounded a => a
minBound forall a. Bounded a => a
maxBound
    ]

------------------------------------------------------------------------
-- Combinators - Choice

-- | Trivial generator that always produces the same element.
--
--   /This is another name for 'pure' \/ 'return'./
constant :: MonadGen m => a -> m a
constant :: forall (m :: * -> *) a. MonadGen m => a -> m a
constant =
  forall (f :: * -> *) a. Applicative f => a -> f a
pure

-- | Randomly selects one of the elements in the list.
--
--   This generator shrinks towards the first element in the list.
--
--   /The input list must be non-empty./
--
element :: MonadGen m => [a] -> m a
element :: forall (m :: * -> *) a. MonadGen m => [a] -> m a
element = \case
  [] ->
    forall a. HasCallStack => String -> a
error String
"Hedgehog.Gen.element: used with empty list"
  [a]
xs -> do
    Int
n <- forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral forall a b. (a -> b) -> a -> b
$ forall a. a -> a -> Range a
Range.constant Int
0 (forall (t :: * -> *) a. Foldable t => t a -> Int
length [a]
xs forall a. Num a => a -> a -> a
- Int
1)
    pure $ [a]
xs forall a. [a] -> Int -> a
!! Int
n

-- | Randomly selects one of the elements in the list.
--
--   This generator does not shrink the choice of element.
--
--   /The input list must be non-empty./
--
element_ :: MonadGen m => [a] -> m a
element_ :: forall (m :: * -> *) a. MonadGen m => [a] -> m a
element_ = \case
  [] ->
    forall a. HasCallStack => String -> a
error String
"Hedgehog.Gen.element: used with empty list"
  [a]
xs -> do
    Int
n <- forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral_ forall a b. (a -> b) -> a -> b
$ forall a. a -> a -> Range a
Range.constant Int
0 (forall (t :: * -> *) a. Foldable t => t a -> Int
length [a]
xs forall a. Num a => a -> a -> a
- Int
1)
    pure $ [a]
xs forall a. [a] -> Int -> a
!! Int
n

-- | Randomly selects one of the generators in the list.
--
--   This generator shrinks towards the first generator in the list.
--
--   /The input list must be non-empty./
--
choice :: MonadGen m => [m a] -> m a
choice :: forall (m :: * -> *) a. MonadGen m => [m a] -> m a
choice = \case
  [] ->
    forall a. HasCallStack => String -> a
error String
"Hedgehog.Gen.choice: used with empty list"
  [m a]
xs -> do
    Int
n <- forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral forall a b. (a -> b) -> a -> b
$ forall a. a -> a -> Range a
Range.constant Int
0 (forall (t :: * -> *) a. Foldable t => t a -> Int
length [m a]
xs forall a. Num a => a -> a -> a
- Int
1)
    [m a]
xs forall a. [a] -> Int -> a
!! Int
n

-- | Uses a weighted distribution to randomly select one of the generators in
--   the list.
--
--   This generator shrinks towards the first generator in the list.
--
--   /The input list must be non-empty./
--
frequency :: MonadGen m => [(Int, m a)] -> m a
frequency :: forall (m :: * -> *) a. MonadGen m => [(Int, m a)] -> m a
frequency = \case
  [] ->
    forall a. HasCallStack => String -> a
error String
"Hedgehog.Gen.frequency: used with empty list"
  [(Int, m a)]
xs0 -> do
    let
      pick :: t -> [(t, a)] -> a
pick t
n = \case
        [] ->
          forall a. HasCallStack => String -> a
error String
"Hedgehog.Gen.frequency/pick: used with empty list"
        (t
k, a
x) : [(t, a)]
xs ->
          if t
n forall a. Ord a => a -> a -> Bool
<= t
k then
            a
x
          else
            t -> [(t, a)] -> a
pick (t
n forall a. Num a => a -> a -> a
- t
k) [(t, a)]
xs

      iis :: [Int]
iis =
        forall a. (a -> a -> a) -> [a] -> [a]
scanl1 forall a. Num a => a -> a -> a
(+) (forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall a b. (a, b) -> a
fst [(Int, m a)]
xs0)

      total :: Int
total =
        forall (t :: * -> *) a. (Foldable t, Num a) => t a -> a
sum (forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall a b. (a, b) -> a
fst [(Int, m a)]
xs0)

    Int
n <- forall (m :: * -> *) a. MonadGen m => (a -> [a]) -> m a -> m a
shrink (\Int
n -> forall a. (a -> Bool) -> [a] -> [a]
takeWhile (forall a. Ord a => a -> a -> Bool
< Int
n) [Int]
iis) forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral_ forall a b. (a -> b) -> a -> b
$ forall a. a -> a -> Range a
Range.constant Int
1 Int
total
    forall {t} {a}. (Ord t, Num t) => t -> [(t, a)] -> a
pick Int
n [(Int, m a)]
xs0

-- | Modifies combinators which choose from a list of generators, like 'choice'
--   or 'frequency', so that they can be used in recursive scenarios.
--
--   This combinator modifies its target to select one of the generators in
--   either the non-recursive or the recursive list. When a selection is made
--   from the recursive list, the 'Size' is halved. When the 'Size' gets to one
--   or less, selections are no longer made from the recursive list, this
--   ensures termination.
--
--   A good example of where this might be useful is abstract syntax trees:
--
-- @
-- data Expr =
--     Var String
--   | Lam String Expr
--   | App Expr Expr
--
-- -- Assuming we have a name generator
-- genName :: 'MonadGen' m => m String
--
-- -- We can write a generator for expressions
-- genExpr :: 'MonadGen' m => m Expr
-- genExpr =
--   Gen.'recursive' Gen.'choice' [
--       -- non-recursive generators
--       Var '<$>' genName
--     ] [
--       -- recursive generators
--       Gen.'subtermM' genExpr (\x -> Lam '<$>' genName '<*>' pure x)
--     , Gen.'subterm2' genExpr genExpr App
--     ]
-- @
--
--   If we wrote the above example using only 'choice', it is likely that it
--   would fail to terminate. This is because for every call to @genExpr@,
--   there is a 2 in 3 chance that we will recurse again.
--
recursive :: MonadGen m => ([m a] -> m a) -> [m a] -> [m a] -> m a
recursive :: forall (m :: * -> *) a.
MonadGen m =>
([m a] -> m a) -> [m a] -> [m a] -> m a
recursive [m a] -> m a
f [m a]
nonrec [m a]
rec =
  forall (m :: * -> *) a. MonadGen m => (Size -> m a) -> m a
sized forall a b. (a -> b) -> a -> b
$ \Size
n ->
    if Size
n forall a. Ord a => a -> a -> Bool
<= Size
1 then
      [m a] -> m a
f [m a]
nonrec
    else
      [m a] -> m a
f forall a b. (a -> b) -> a -> b
$ [m a]
nonrec forall a. [a] -> [a] -> [a]
++ forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall (m :: * -> *) a. MonadGen m => m a -> m a
small [m a]
rec

------------------------------------------------------------------------
-- Combinators - Conditional

-- | Discards the whole generator.
--
discard :: MonadGen m => m a
discard :: forall (m :: * -> *) a. MonadGen m => m a
discard =
  forall (m :: * -> *) a. MonadGen m => GenT (GenBase m) a -> m a
fromGenT forall (f :: * -> *) a. Alternative f => f a
empty

-- | Discards the generator if the generated value does not satisfy the
--   predicate.
--
ensure :: MonadGen m => (a -> Bool) -> m a -> m a
ensure :: forall (m :: * -> *) a. MonadGen m => (a -> Bool) -> m a -> m a
ensure a -> Bool
p m a
gen = do
  a
x <- m a
gen
  if a -> Bool
p a
x then
    forall (f :: * -> *) a. Applicative f => a -> f a
pure a
x
  else
    forall (m :: * -> *) a. MonadGen m => m a
discard

fromPred :: (a -> Bool) -> a -> Maybe a
fromPred :: forall a. (a -> Bool) -> a -> Maybe a
fromPred a -> Bool
p a
a = a
a forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ forall (f :: * -> *). Alternative f => Bool -> f ()
guard (a -> Bool
p a
a)

-- | Generates a value that satisfies a predicate.
--
--   This is essentially:
--
-- @
--   filter p gen = 'mfilter' p gen '<|>' filter p gen
-- @
--
--   It differs from the above in that we keep some state to avoid looping
--   forever. If we trigger these limits then the whole generator is discarded.
--
filter :: (MonadGen m, GenBase m ~ Identity) => (a -> Bool) -> m a -> m a
filter :: forall (m :: * -> *) a.
(MonadGen m, GenBase m ~ Identity) =>
(a -> Bool) -> m a -> m a
filter a -> Bool
p =
  forall (m :: * -> *) a b.
(MonadGen m, GenBase m ~ Identity) =>
(a -> Maybe b) -> m a -> m b
mapMaybe (forall a. (a -> Bool) -> a -> Maybe a
fromPred a -> Bool
p)

mapMaybe :: (MonadGen m, GenBase m ~ Identity) => (a -> Maybe b) -> m a -> m b
mapMaybe :: forall (m :: * -> *) a b.
(MonadGen m, GenBase m ~ Identity) =>
(a -> Maybe b) -> m a -> m b
mapMaybe a -> Maybe b
p m a
gen0 =
  let
    try :: Size -> m b
try Size
k =
      if Size
k forall a. Ord a => a -> a -> Bool
> Size
100 then
        forall (m :: * -> *) a. MonadGen m => m a
discard
      else do
        (a
x, m a
gen) <- forall (m :: * -> *) a. MonadGen m => m a -> m (a, m a)
freeze forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. MonadGen m => (Size -> Size) -> m a -> m a
scale (Size
2 forall a. Num a => a -> a -> a
* Size
k forall a. Num a => a -> a -> a
+) m a
gen0

        case a -> Maybe b
p a
x of
          Just b
_ ->
            forall (m :: * -> *) (n :: * -> *) a b.
(MonadGen m, MonadGen n) =>
(GenT (GenBase m) a -> GenT (GenBase n) b) -> m a -> n b
withGenT (forall (m :: * -> *) a (n :: * -> *) b.
(TreeT (MaybeT m) a -> TreeT (MaybeT n) b) -> GenT m a -> GenT n b
mapGenT (forall a b.
(a -> Maybe b)
-> TreeT (MaybeT Identity) a -> TreeT (MaybeT Identity) b
Tree.mapMaybeMaybeT a -> Maybe b
p)) m a
gen
          Maybe b
Nothing ->
            Size -> m b
try (Size
k forall a. Num a => a -> a -> a
+ Size
1)
  in
    Size -> m b
try Size
0

filterT :: MonadGen m => (a -> Bool) -> m a -> m a
filterT :: forall (m :: * -> *) a. MonadGen m => (a -> Bool) -> m a -> m a
filterT a -> Bool
p =
  forall (m :: * -> *) a b.
MonadGen m =>
(a -> Maybe b) -> m a -> m b
mapMaybeT (forall a. (a -> Bool) -> a -> Maybe a
fromPred a -> Bool
p)

mapMaybeT :: MonadGen m => (a -> Maybe b) -> m a -> m b
mapMaybeT :: forall (m :: * -> *) a b.
MonadGen m =>
(a -> Maybe b) -> m a -> m b
mapMaybeT a -> Maybe b
p m a
gen0 =
  let
    try :: Size -> m b
try Size
k =
      if Size
k forall a. Ord a => a -> a -> Bool
> Size
100 then
        forall (m :: * -> *) a. MonadGen m => m a
discard
      else do
        (a
x, m a
gen) <- forall (m :: * -> *) a. MonadGen m => m a -> m (a, m a)
freeze forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. MonadGen m => (Size -> Size) -> m a -> m a
scale (Size
2 forall a. Num a => a -> a -> a
* Size
k forall a. Num a => a -> a -> a
+) m a
gen0

        case a -> Maybe b
p a
x of
          Just b
_ ->
            forall (m :: * -> *) (n :: * -> *) a b.
(MonadGen m, MonadGen n) =>
(GenT (GenBase m) a -> GenT (GenBase n) b) -> m a -> n b
withGenT (forall (m :: * -> *) a (n :: * -> *) b.
(TreeT (MaybeT m) a -> TreeT (MaybeT n) b) -> GenT m a -> GenT n b
mapGenT (forall (m :: * -> *) a b.
(Monad m, Alternative m) =>
(a -> Maybe b) -> TreeT m a -> TreeT m b
Tree.mapMaybeT a -> Maybe b
p)) m a
gen
          Maybe b
Nothing ->
            Size -> m b
try (Size
k forall a. Num a => a -> a -> a
+ Size
1)
  in
    Size -> m b
try Size
0

-- | Runs a 'Maybe' generator until it produces a 'Just'.
--
--   /This is implemented using 'filter' and has the same caveats./
--
just :: (MonadGen m, GenBase m ~ Identity) => m (Maybe a) -> m a
just :: forall (m :: * -> *) a.
(MonadGen m, GenBase m ~ Identity) =>
m (Maybe a) -> m a
just m (Maybe a)
g = do
  Maybe a
mx <- forall (m :: * -> *) a.
(MonadGen m, GenBase m ~ Identity) =>
(a -> Bool) -> m a -> m a
filter forall a. Maybe a -> Bool
Maybe.isJust m (Maybe a)
g
  case Maybe a
mx of
    Just a
x ->
      forall (f :: * -> *) a. Applicative f => a -> f a
pure a
x
    Maybe a
Nothing ->
      forall a. HasCallStack => String -> a
error String
"Hedgehog.Gen.just: internal error, unexpected Nothing"

-- | Runs a 'Maybe' generator until it produces a 'Just'.
--
--   /This is implemented using 'filter' and has the same caveats./
--
justT :: MonadGen m => m (Maybe a) -> m a
justT :: forall (m :: * -> *) a. MonadGen m => m (Maybe a) -> m a
justT m (Maybe a)
g = do
  Maybe a
mx <- forall (m :: * -> *) a. MonadGen m => (a -> Bool) -> m a -> m a
filterT forall a. Maybe a -> Bool
Maybe.isJust m (Maybe a)
g
  case Maybe a
mx of
    Just a
x ->
      forall (f :: * -> *) a. Applicative f => a -> f a
pure a
x
    Maybe a
Nothing ->
      forall a. HasCallStack => String -> a
error String
"Hedgehog.Gen.just: internal error, unexpected Nothing"

------------------------------------------------------------------------
-- Combinators - Collections

-- | Generates a 'Nothing' some of the time.
--
maybe :: MonadGen m => m a -> m (Maybe a)
maybe :: forall (m :: * -> *) a. MonadGen m => m a -> m (Maybe a)
maybe m a
gen =
  forall (m :: * -> *) a. MonadGen m => (Size -> m a) -> m a
sized forall a b. (a -> b) -> a -> b
$ \Size
n ->
    forall (m :: * -> *) a. MonadGen m => [(Int, m a)] -> m a
frequency [
        (Int
2, forall (f :: * -> *) a. Applicative f => a -> f a
pure forall a. Maybe a
Nothing)
      , (Int
1 forall a. Num a => a -> a -> a
+ forall a b. (Integral a, Num b) => a -> b
fromIntegral Size
n, forall a. a -> Maybe a
Just forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> m a
gen)
      ]

-- | Generates either an 'a' or a 'b'.
--
--   As the size grows, this generator generates @Right@s more often than @Left@s.
--
either :: MonadGen m => m a -> m b -> m (Either a b)
either :: forall (m :: * -> *) a b.
MonadGen m =>
m a -> m b -> m (Either a b)
either m a
genA m b
genB =
  forall (m :: * -> *) a. MonadGen m => (Size -> m a) -> m a
sized forall a b. (a -> b) -> a -> b
$ \Size
n ->
    forall (m :: * -> *) a. MonadGen m => [(Int, m a)] -> m a
frequency [
        (Int
2, forall a b. a -> Either a b
Left forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> m a
genA)
      , (Int
1 forall a. Num a => a -> a -> a
+ forall a b. (Integral a, Num b) => a -> b
fromIntegral Size
n, forall a b. b -> Either a b
Right forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> m b
genB)
      ]

-- | Generates either an 'a' or a 'b', without bias.
--
--   This generator generates as many @Right@s as it does @Left@s.
--
either_ :: MonadGen m => m a -> m b -> m (Either a b)
either_ :: forall (m :: * -> *) a b.
MonadGen m =>
m a -> m b -> m (Either a b)
either_ m a
genA m b
genB =
    forall (m :: * -> *) a. MonadGen m => [m a] -> m a
choice [
      forall a b. a -> Either a b
Left forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> m a
genA
    , forall a b. b -> Either a b
Right forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> m b
genB
    ]

-- | Generates a list using a 'Range' to determine the length.
--
list :: MonadGen m => Range Int -> m a -> m [a]
list :: forall (m :: * -> *) a. MonadGen m => Range Int -> m a -> m [a]
list Range Int
range m a
gen =
  let
     interleave :: MaybeT (GenBase m) (NodeT m [TreeT (MaybeT (GenBase m)) a])
-> MaybeT (GenBase m) (NodeT (MaybeT (GenBase m)) [a])
interleave =
       (forall (m :: * -> *) a. Monad m => [TreeT m a] -> m (NodeT m [a])
interleaveTreeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. NodeT m a -> a
nodeValue forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
=<<)
  in
    forall (m :: * -> *) a. MonadGen m => (Size -> m a) -> m a
sized forall a b. (a -> b) -> a -> b
$ \Size
size ->
      forall (m :: * -> *) a. MonadGen m => (a -> Bool) -> m a -> m a
ensure (forall a. Int -> [a] -> Bool
atLeast forall a b. (a -> b) -> a -> b
$ forall a. Ord a => Size -> Range a -> a
Range.lowerBound Size
size Range Int
range) forall b c a. (b -> c) -> (a -> b) -> a -> c
.
      forall (m :: * -> *) (n :: * -> *) a b.
(MonadGen m, MonadGen n) =>
(GenT (GenBase m) a -> GenT (GenBase n) b) -> m a -> n b
withGenT (forall (m :: * -> *) a (n :: * -> *) b.
(TreeT (MaybeT m) a -> TreeT (MaybeT n) b) -> GenT m a -> GenT n b
mapGenT (forall (m :: * -> *) a. m (NodeT m a) -> TreeT m a
TreeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall {m :: * -> *} {a}.
MaybeT (GenBase m) (NodeT m [TreeT (MaybeT (GenBase m)) a])
-> MaybeT (GenBase m) (NodeT (MaybeT (GenBase m)) [a])
interleave forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. TreeT m a -> m (NodeT m a)
runTreeT)) forall a b. (a -> b) -> a -> b
$ do
        Int
n <- forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral_ Range Int
range
        forall (m :: * -> *) a. Applicative m => Int -> m a -> m [a]
replicateM Int
n (forall (m :: * -> *) a.
MonadGen m =>
m a -> m (TreeT (MaybeT (GenBase m)) a)
toTreeMaybeT m a
gen)

interleaveTreeT :: Monad m => [TreeT m a] -> m (NodeT m [a])
interleaveTreeT :: forall (m :: * -> *) a. Monad m => [TreeT m a] -> m (NodeT m [a])
interleaveTreeT =
  forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall (m :: * -> *) a. Monad m => [NodeT m a] -> NodeT m [a]
Tree.interleave forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (t :: * -> *) (f :: * -> *) a b.
(Traversable t, Applicative f) =>
(a -> f b) -> t a -> f (t b)
traverse forall (m :: * -> *) a. TreeT m a -> m (NodeT m a)
runTreeT

-- | Generates a seq using a 'Range' to determine the length.
--
seq :: MonadGen m => Range Int -> m a -> m (Seq a)
seq :: forall (m :: * -> *) a. MonadGen m => Range Int -> m a -> m (Seq a)
seq Range Int
range m a
gen =
  forall a. [a] -> Seq a
Seq.fromList forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *) a. MonadGen m => Range Int -> m a -> m [a]
list Range Int
range m a
gen

-- | Generates a non-empty list using a 'Range' to determine the length.
--
nonEmpty :: MonadGen m => Range Int -> m a -> m (NonEmpty a)
nonEmpty :: forall (m :: * -> *) a.
MonadGen m =>
Range Int -> m a -> m (NonEmpty a)
nonEmpty Range Int
range m a
gen = do
  [a]
xs <- forall (m :: * -> *) a. MonadGen m => Range Int -> m a -> m [a]
list (forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap (forall a. Ord a => a -> a -> a
max Int
1) Range Int
range) m a
gen
  case [a]
xs of
    [] ->
      forall a. HasCallStack => String -> a
error String
"Hedgehog.Gen.nonEmpty: internal error, generated empty list"
    [a]
_ ->
      forall (f :: * -> *) a. Applicative f => a -> f a
pure forall a b. (a -> b) -> a -> b
$ forall a. [a] -> NonEmpty a
NonEmpty.fromList [a]
xs

-- | Generates a set using a 'Range' to determine the length.
--
--   /This may fail to generate anything if the element generator/
--   /cannot produce a large enough number of unique items to satify/
--   /the required set size./
--
set :: (MonadGen m, Ord a) => Range Int -> m a -> m (Set a)
set :: forall (m :: * -> *) a.
(MonadGen m, Ord a) =>
Range Int -> m a -> m (Set a)
set Range Int
range m a
gen =
  forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall k a. Map k a -> Set k
Map.keysSet forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) k v.
(MonadGen m, Ord k) =>
Range Int -> m (k, v) -> m (Map k v)
map Range Int
range forall a b. (a -> b) -> a -> b
$ forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap (, ()) m a
gen

-- | Generates a map using a 'Range' to determine the length.
--
--   /This may fail to generate anything if the keys produced by the/
--   /generator do not account for a large enough number of unique/
--   /items to satify the required map size./
--
map :: (MonadGen m, Ord k) => Range Int -> m (k, v) -> m (Map k v)
map :: forall (m :: * -> *) k v.
(MonadGen m, Ord k) =>
Range Int -> m (k, v) -> m (Map k v)
map Range Int
range m (k, v)
gen =
  forall (m :: * -> *) a. MonadGen m => (Size -> m a) -> m a
sized forall a b. (a -> b) -> a -> b
$ \Size
size ->
    forall (m :: * -> *) a. MonadGen m => (a -> Bool) -> m a -> m a
ensure ((forall a. Ord a => a -> a -> Bool
>= forall a. Ord a => Size -> Range a -> a
Range.lowerBound Size
size Range Int
range) forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall k a. Map k a -> Int
Map.size) forall b c a. (b -> c) -> (a -> b) -> a -> c
.
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall k a. Ord k => [(k, a)] -> Map k a
Map.fromList forall b c a. (b -> c) -> (a -> b) -> a -> c
.
    (forall (t :: * -> *) (m :: * -> *) a.
(Traversable t, Monad m) =>
t (m a) -> m (t a)
sequence forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
=<<) forall b c a. (b -> c) -> (a -> b) -> a -> c
.
    forall (m :: * -> *) a. MonadGen m => (a -> [a]) -> m a -> m a
shrink forall a. [a] -> [[a]]
Shrink.list forall a b. (a -> b) -> a -> b
$ do
      Int
k <- forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral_ Range Int
range
      forall (m :: * -> *) k v.
(MonadGen m, Ord k) =>
Int -> m (k, v) -> m [m (k, v)]
uniqueByKey Int
k m (k, v)
gen

-- | Generate exactly 'n' unique generators.
--
uniqueByKey :: (MonadGen m, Ord k) => Int -> m (k, v) -> m [m (k, v)]
uniqueByKey :: forall (m :: * -> *) k v.
(MonadGen m, Ord k) =>
Int -> m (k, v) -> m [m (k, v)]
uniqueByKey Int
n m (k, v)
gen =
  let
    try :: Int -> Map k (m (k, v)) -> m [m (k, v)]
try Int
k Map k (m (k, v))
xs0 =
      if Int
k forall a. Ord a => a -> a -> Bool
> Int
100 then
        forall (m :: * -> *) a. MonadGen m => m a
discard
      else
        forall (m :: * -> *) a. Applicative m => Int -> m a -> m [a]
replicateM Int
n (forall (m :: * -> *) a. MonadGen m => m a -> m (a, m a)
freeze m (k, v)
gen) forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= \[((k, v), m (k, v))]
kvs ->
        case forall k v.
Ord k =>
Int -> Map k v -> [(k, v)] -> Either (Map k v) (Map k v)
uniqueInsert Int
n Map k (m (k, v))
xs0 (forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap (forall (p :: * -> * -> *) a b c.
Bifunctor p =>
(a -> b) -> p a c -> p b c
first forall a b. (a, b) -> a
fst) [((k, v), m (k, v))]
kvs) of
          Left Map k (m (k, v))
xs ->
            forall (f :: * -> *) a. Applicative f => a -> f a
pure forall a b. (a -> b) -> a -> b
$ forall k a. Map k a -> [a]
Map.elems Map k (m (k, v))
xs
          Right Map k (m (k, v))
xs ->
            Int -> Map k (m (k, v)) -> m [m (k, v)]
try (Int
k forall a. Num a => a -> a -> a
+ Int
1) Map k (m (k, v))
xs
  in
    Int -> Map k (m (k, v)) -> m [m (k, v)]
try (Int
0 :: Int) forall k a. Map k a
Map.empty

uniqueInsert :: Ord k => Int -> Map k v -> [(k, v)] -> Either (Map k v) (Map k v)
uniqueInsert :: forall k v.
Ord k =>
Int -> Map k v -> [(k, v)] -> Either (Map k v) (Map k v)
uniqueInsert Int
n Map k v
xs [(k, v)]
kvs0 =
  if forall k a. Map k a -> Int
Map.size Map k v
xs forall a. Ord a => a -> a -> Bool
>= Int
n then
    forall a b. a -> Either a b
Left Map k v
xs
  else
    case [(k, v)]
kvs0 of
      [] ->
        forall a b. b -> Either a b
Right Map k v
xs
      (k
k, v
v) : [(k, v)]
kvs ->
        forall k v.
Ord k =>
Int -> Map k v -> [(k, v)] -> Either (Map k v) (Map k v)
uniqueInsert Int
n (forall k a. Ord k => (a -> a -> a) -> k -> a -> Map k a -> Map k a
Map.insertWith (\v
x v
_ -> v
x) k
k v
v Map k v
xs) [(k, v)]
kvs

-- | Check that list contains at least a certain number of elements.
--
atLeast :: Int -> [a] -> Bool
atLeast :: forall a. Int -> [a] -> Bool
atLeast Int
n =
  if Int
n forall a. Eq a => a -> a -> Bool
== Int
0 then
    forall a b. a -> b -> a
const Bool
True
  else
    Bool -> Bool
not forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (t :: * -> *) a. Foldable t => t a -> Bool
null forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Int -> [a] -> [a]
drop (Int
n forall a. Num a => a -> a -> a
- Int
1)

------------------------------------------------------------------------
-- Combinators - Subterms

data Subterms n a =
    One a
  | All (Vec n a)
    deriving (forall a b. a -> Subterms n b -> Subterms n a
forall a b. (a -> b) -> Subterms n a -> Subterms n b
forall (n :: Nat) a b. a -> Subterms n b -> Subterms n a
forall (n :: Nat) a b. (a -> b) -> Subterms n a -> Subterms n b
forall (f :: * -> *).
(forall a b. (a -> b) -> f a -> f b)
-> (forall a b. a -> f b -> f a) -> Functor f
<$ :: forall a b. a -> Subterms n b -> Subterms n a
$c<$ :: forall (n :: Nat) a b. a -> Subterms n b -> Subterms n a
fmap :: forall a b. (a -> b) -> Subterms n a -> Subterms n b
$cfmap :: forall (n :: Nat) a b. (a -> b) -> Subterms n a -> Subterms n b
Functor, forall a. Subterms n a -> Bool
forall m a. Monoid m => (a -> m) -> Subterms n a -> m
forall a b. (a -> b -> b) -> b -> Subterms n a -> b
forall (n :: Nat) a. Eq a => a -> Subterms n a -> Bool
forall (n :: Nat) a. Num a => Subterms n a -> a
forall (n :: Nat) a. Ord a => Subterms n a -> a
forall (n :: Nat) m. Monoid m => Subterms n m -> m
forall (n :: Nat) a. Subterms n a -> Bool
forall (n :: Nat) a. Subterms n a -> Int
forall (n :: Nat) a. Subterms n a -> [a]
forall (n :: Nat) a. (a -> a -> a) -> Subterms n a -> a
forall (n :: Nat) m a. Monoid m => (a -> m) -> Subterms n a -> m
forall (n :: Nat) b a. (b -> a -> b) -> b -> Subterms n a -> b
forall (n :: Nat) a b. (a -> b -> b) -> b -> Subterms n a -> b
forall (t :: * -> *).
(forall m. Monoid m => t m -> m)
-> (forall m a. Monoid m => (a -> m) -> t a -> m)
-> (forall m a. Monoid m => (a -> m) -> t a -> m)
-> (forall a b. (a -> b -> b) -> b -> t a -> b)
-> (forall a b. (a -> b -> b) -> b -> t a -> b)
-> (forall b a. (b -> a -> b) -> b -> t a -> b)
-> (forall b a. (b -> a -> b) -> b -> t a -> b)
-> (forall a. (a -> a -> a) -> t a -> a)
-> (forall a. (a -> a -> a) -> t a -> a)
-> (forall a. t a -> [a])
-> (forall a. t a -> Bool)
-> (forall a. t a -> Int)
-> (forall a. Eq a => a -> t a -> Bool)
-> (forall a. Ord a => t a -> a)
-> (forall a. Ord a => t a -> a)
-> (forall a. Num a => t a -> a)
-> (forall a. Num a => t a -> a)
-> Foldable t
product :: forall a. Num a => Subterms n a -> a
$cproduct :: forall (n :: Nat) a. Num a => Subterms n a -> a
sum :: forall a. Num a => Subterms n a -> a
$csum :: forall (n :: Nat) a. Num a => Subterms n a -> a
minimum :: forall a. Ord a => Subterms n a -> a
$cminimum :: forall (n :: Nat) a. Ord a => Subterms n a -> a
maximum :: forall a. Ord a => Subterms n a -> a
$cmaximum :: forall (n :: Nat) a. Ord a => Subterms n a -> a
elem :: forall a. Eq a => a -> Subterms n a -> Bool
$celem :: forall (n :: Nat) a. Eq a => a -> Subterms n a -> Bool
length :: forall a. Subterms n a -> Int
$clength :: forall (n :: Nat) a. Subterms n a -> Int
null :: forall a. Subterms n a -> Bool
$cnull :: forall (n :: Nat) a. Subterms n a -> Bool
toList :: forall a. Subterms n a -> [a]
$ctoList :: forall (n :: Nat) a. Subterms n a -> [a]
foldl1 :: forall a. (a -> a -> a) -> Subterms n a -> a
$cfoldl1 :: forall (n :: Nat) a. (a -> a -> a) -> Subterms n a -> a
foldr1 :: forall a. (a -> a -> a) -> Subterms n a -> a
$cfoldr1 :: forall (n :: Nat) a. (a -> a -> a) -> Subterms n a -> a
foldl' :: forall b a. (b -> a -> b) -> b -> Subterms n a -> b
$cfoldl' :: forall (n :: Nat) b a. (b -> a -> b) -> b -> Subterms n a -> b
foldl :: forall b a. (b -> a -> b) -> b -> Subterms n a -> b
$cfoldl :: forall (n :: Nat) b a. (b -> a -> b) -> b -> Subterms n a -> b
foldr' :: forall a b. (a -> b -> b) -> b -> Subterms n a -> b
$cfoldr' :: forall (n :: Nat) a b. (a -> b -> b) -> b -> Subterms n a -> b
foldr :: forall a b. (a -> b -> b) -> b -> Subterms n a -> b
$cfoldr :: forall (n :: Nat) a b. (a -> b -> b) -> b -> Subterms n a -> b
foldMap' :: forall m a. Monoid m => (a -> m) -> Subterms n a -> m
$cfoldMap' :: forall (n :: Nat) m a. Monoid m => (a -> m) -> Subterms n a -> m
foldMap :: forall m a. Monoid m => (a -> m) -> Subterms n a -> m
$cfoldMap :: forall (n :: Nat) m a. Monoid m => (a -> m) -> Subterms n a -> m
fold :: forall m. Monoid m => Subterms n m -> m
$cfold :: forall (n :: Nat) m. Monoid m => Subterms n m -> m
Foldable, forall (n :: Nat). Functor (Subterms n)
forall (n :: Nat). Foldable (Subterms n)
forall (n :: Nat) (m :: * -> *) a.
Monad m =>
Subterms n (m a) -> m (Subterms n a)
forall (n :: Nat) (f :: * -> *) a.
Applicative f =>
Subterms n (f a) -> f (Subterms n a)
forall (n :: Nat) (m :: * -> *) a b.
Monad m =>
(a -> m b) -> Subterms n a -> m (Subterms n b)
forall (n :: Nat) (f :: * -> *) a b.
Applicative f =>
(a -> f b) -> Subterms n a -> f (Subterms n b)
forall (t :: * -> *).
Functor t
-> Foldable t
-> (forall (f :: * -> *) a b.
    Applicative f =>
    (a -> f b) -> t a -> f (t b))
-> (forall (f :: * -> *) a. Applicative f => t (f a) -> f (t a))
-> (forall (m :: * -> *) a b.
    Monad m =>
    (a -> m b) -> t a -> m (t b))
-> (forall (m :: * -> *) a. Monad m => t (m a) -> m (t a))
-> Traversable t
forall (f :: * -> *) a b.
Applicative f =>
(a -> f b) -> Subterms n a -> f (Subterms n b)
sequence :: forall (m :: * -> *) a.
Monad m =>
Subterms n (m a) -> m (Subterms n a)
$csequence :: forall (n :: Nat) (m :: * -> *) a.
Monad m =>
Subterms n (m a) -> m (Subterms n a)
mapM :: forall (m :: * -> *) a b.
Monad m =>
(a -> m b) -> Subterms n a -> m (Subterms n b)
$cmapM :: forall (n :: Nat) (m :: * -> *) a b.
Monad m =>
(a -> m b) -> Subterms n a -> m (Subterms n b)
sequenceA :: forall (f :: * -> *) a.
Applicative f =>
Subterms n (f a) -> f (Subterms n a)
$csequenceA :: forall (n :: Nat) (f :: * -> *) a.
Applicative f =>
Subterms n (f a) -> f (Subterms n a)
traverse :: forall (f :: * -> *) a b.
Applicative f =>
(a -> f b) -> Subterms n a -> f (Subterms n b)
$ctraverse :: forall (n :: Nat) (f :: * -> *) a b.
Applicative f =>
(a -> f b) -> Subterms n a -> f (Subterms n b)
Traversable)

data Nat =
    Z
  | S Nat

data Vec n a where
  Nil :: Vec 'Z a
  (:.) :: a -> Vec n a -> Vec ('S n) a

infixr 5 :.

deriving instance Functor (Vec n)
deriving instance Foldable (Vec n)
deriving instance Traversable (Vec n)

-- | Freeze the size and seed used by a generator, so we can inspect the value
--   which it will produce.
--
--   This is used for implementing `list` and `subtermMVec`. It allows us to
--   shrink the list itself before trying to shrink the values inside the list.
--
freeze :: MonadGen m => m a -> m (a, m a)
freeze :: forall (m :: * -> *) a. MonadGen m => m a -> m (a, m a)
freeze =
  forall (m :: * -> *) (n :: * -> *) a b.
(MonadGen m, MonadGen n) =>
(GenT (GenBase m) a -> GenT (GenBase n) b) -> m a -> n b
withGenT forall a b. (a -> b) -> a -> b
$ \GenT (GenBase m) a
gen ->
    forall (m :: * -> *) a.
(Size -> Seed -> TreeT (MaybeT m) a) -> GenT m a
GenT forall a b. (a -> b) -> a -> b
$ \Size
size Seed
seed -> do
      Maybe (NodeT (MaybeT (GenBase m)) a)
mx <- forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(MonadTrans t, Monad m) =>
m a -> t m a
lift forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. MaybeT m a -> m (Maybe a)
runMaybeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. TreeT m a -> m (NodeT m a)
runTreeT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a.
Size -> Seed -> GenT m a -> TreeT (MaybeT m) a
runGenT Size
size Seed
seed GenT (GenBase m) a
gen
      case Maybe (NodeT (MaybeT (GenBase m)) a)
mx of
        Maybe (NodeT (MaybeT (GenBase m)) a)
Nothing ->
          forall (f :: * -> *) a. Alternative f => f a
empty
        Just (NodeT a
x [TreeT (MaybeT (GenBase m)) a]
xs) ->
          forall (f :: * -> *) a. Applicative f => a -> f a
pure (a
x, forall (m :: * -> *) a. MonadGen m => GenT (GenBase m) a -> m a
fromGenT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a.
MonadGen m =>
TreeT (MaybeT (GenBase m)) a -> m a
fromTreeMaybeT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. Applicative m => NodeT m a -> TreeT m a
Tree.fromNodeT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. a -> [TreeT m a] -> NodeT m a
NodeT a
x [TreeT (MaybeT (GenBase m)) a]
xs)

shrinkSubterms :: Subterms n a -> [Subterms n a]
shrinkSubterms :: forall (n :: Nat) a. Subterms n a -> [Subterms n a]
shrinkSubterms = \case
  One a
_ ->
    []
  All Vec n a
xs ->
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall (n :: Nat) a. a -> Subterms n a
One forall a b. (a -> b) -> a -> b
$ forall (t :: * -> *) a. Foldable t => t a -> [a]
toList Vec n a
xs

genSubterms :: MonadGen m => Vec n (m a) -> m (Subterms n a)
genSubterms :: forall (m :: * -> *) (n :: Nat) a.
MonadGen m =>
Vec n (m a) -> m (Subterms n a)
genSubterms =
  (forall (t :: * -> *) (m :: * -> *) a.
(Traversable t, Monad m) =>
t (m a) -> m (t a)
sequence forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
=<<) forall b c a. (b -> c) -> (a -> b) -> a -> c
.
  forall (m :: * -> *) a. MonadGen m => (a -> [a]) -> m a -> m a
shrink forall (n :: Nat) a. Subterms n a -> [Subterms n a]
shrinkSubterms forall b c a. (b -> c) -> (a -> b) -> a -> c
.
  forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall (n :: Nat) a. Vec n a -> Subterms n a
All forall b c a. (b -> c) -> (a -> b) -> a -> c
.
  forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM (forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall a b. (a, b) -> b
snd forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. MonadGen m => m a -> m (a, m a)
freeze)

fromSubterms :: Applicative m => (Vec n a -> m a) -> Subterms n a -> m a
fromSubterms :: forall (m :: * -> *) (n :: Nat) a.
Applicative m =>
(Vec n a -> m a) -> Subterms n a -> m a
fromSubterms Vec n a -> m a
f = \case
  One a
x ->
    forall (f :: * -> *) a. Applicative f => a -> f a
pure a
x
  All Vec n a
xs ->
    Vec n a -> m a
f Vec n a
xs

-- | Constructs a generator from a number of sub-term generators.
--
--   /Shrinks to one of the sub-terms if possible./
--
subtermMVec :: MonadGen m => Vec n (m a) -> (Vec n a -> m a) -> m a
subtermMVec :: forall (m :: * -> *) (n :: Nat) a.
MonadGen m =>
Vec n (m a) -> (Vec n a -> m a) -> m a
subtermMVec Vec n (m a)
gs Vec n a -> m a
f =
  forall (m :: * -> *) (n :: Nat) a.
Applicative m =>
(Vec n a -> m a) -> Subterms n a -> m a
fromSubterms Vec n a -> m a
f forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
=<< forall (m :: * -> *) (n :: Nat) a.
MonadGen m =>
Vec n (m a) -> m (Subterms n a)
genSubterms Vec n (m a)
gs

-- | Constructs a generator from a sub-term generator.
--
--   /Shrinks to the sub-term if possible./
--
subtermM :: MonadGen m => m a -> (a -> m a) -> m a
subtermM :: forall (m :: * -> *) a. MonadGen m => m a -> (a -> m a) -> m a
subtermM m a
gx a -> m a
f =
  forall (m :: * -> *) (n :: Nat) a.
MonadGen m =>
Vec n (m a) -> (Vec n a -> m a) -> m a
subtermMVec (m a
gx forall a (n :: Nat). a -> Vec n a -> Vec ('S n) a
:. forall a. Vec 'Z a
Nil) forall a b. (a -> b) -> a -> b
$ \(a
x :. Vec n a
Nil) ->
    a -> m a
f a
x

-- | Constructs a generator from a sub-term generator.
--
--   /Shrinks to the sub-term if possible./
--
subterm :: MonadGen m => m a -> (a -> a) -> m a
subterm :: forall (m :: * -> *) a. MonadGen m => m a -> (a -> a) -> m a
subterm m a
gx a -> a
f =
  forall (m :: * -> *) a. MonadGen m => m a -> (a -> m a) -> m a
subtermM m a
gx forall a b. (a -> b) -> a -> b
$ \a
x ->
    forall (f :: * -> *) a. Applicative f => a -> f a
pure (a -> a
f a
x)

-- | Constructs a generator from two sub-term generators.
--
--   /Shrinks to one of the sub-terms if possible./
--
subtermM2 :: MonadGen m => m a -> m a -> (a -> a -> m a) -> m a
subtermM2 :: forall (m :: * -> *) a.
MonadGen m =>
m a -> m a -> (a -> a -> m a) -> m a
subtermM2 m a
gx m a
gy a -> a -> m a
f =
  forall (m :: * -> *) (n :: Nat) a.
MonadGen m =>
Vec n (m a) -> (Vec n a -> m a) -> m a
subtermMVec (m a
gx forall a (n :: Nat). a -> Vec n a -> Vec ('S n) a
:. m a
gy forall a (n :: Nat). a -> Vec n a -> Vec ('S n) a
:. forall a. Vec 'Z a
Nil) forall a b. (a -> b) -> a -> b
$ \(a
x :. a
y :. Vec n a
Nil) ->
    a -> a -> m a
f a
x a
y

-- | Constructs a generator from two sub-term generators.
--
--   /Shrinks to one of the sub-terms if possible./
--
subterm2 :: MonadGen m => m a -> m a -> (a -> a -> a) -> m a
subterm2 :: forall (m :: * -> *) a.
MonadGen m =>
m a -> m a -> (a -> a -> a) -> m a
subterm2 m a
gx m a
gy a -> a -> a
f =
  forall (m :: * -> *) a.
MonadGen m =>
m a -> m a -> (a -> a -> m a) -> m a
subtermM2 m a
gx m a
gy forall a b. (a -> b) -> a -> b
$ \a
x a
y ->
    forall (f :: * -> *) a. Applicative f => a -> f a
pure (a -> a -> a
f a
x a
y)

-- | Constructs a generator from three sub-term generators.
--
--   /Shrinks to one of the sub-terms if possible./
--
subtermM3 :: MonadGen m => m a -> m a -> m a -> (a -> a -> a -> m a) -> m a
subtermM3 :: forall (m :: * -> *) a.
MonadGen m =>
m a -> m a -> m a -> (a -> a -> a -> m a) -> m a
subtermM3 m a
gx m a
gy m a
gz a -> a -> a -> m a
f =
  forall (m :: * -> *) (n :: Nat) a.
MonadGen m =>
Vec n (m a) -> (Vec n a -> m a) -> m a
subtermMVec (m a
gx forall a (n :: Nat). a -> Vec n a -> Vec ('S n) a
:. m a
gy forall a (n :: Nat). a -> Vec n a -> Vec ('S n) a
:. m a
gz forall a (n :: Nat). a -> Vec n a -> Vec ('S n) a
:. forall a. Vec 'Z a
Nil) forall a b. (a -> b) -> a -> b
$ \(a
x :. a
y :. a
z :. Vec n a
Nil) ->
    a -> a -> a -> m a
f a
x a
y a
z

-- | Constructs a generator from three sub-term generators.
--
--   /Shrinks to one of the sub-terms if possible./
--
subterm3 :: MonadGen m => m a -> m a -> m a -> (a -> a -> a -> a) -> m a
subterm3 :: forall (m :: * -> *) a.
MonadGen m =>
m a -> m a -> m a -> (a -> a -> a -> a) -> m a
subterm3 m a
gx m a
gy m a
gz a -> a -> a -> a
f =
  forall (m :: * -> *) a.
MonadGen m =>
m a -> m a -> m a -> (a -> a -> a -> m a) -> m a
subtermM3 m a
gx m a
gy m a
gz forall a b. (a -> b) -> a -> b
$ \a
x a
y a
z ->
    forall (f :: * -> *) a. Applicative f => a -> f a
pure (a -> a -> a -> a
f a
x a
y a
z)

------------------------------------------------------------------------
-- Combinators - Combinations & Permutations

-- | Generates a random subsequence of a list.
--
-- For example:
--
-- @
-- Gen.print (Gen.subsequence [1..5])
-- @
--
--   > === Outcome ===
--   > [1,2,4]
--   > === Shrinks ===
--   > []
--   > [2,4]
--   > [1,4]
--   > [1,2]
--
subsequence :: MonadGen m => [a] -> m [a]
subsequence :: forall (m :: * -> *) a. MonadGen m => [a] -> m [a]
subsequence [a]
xs =
  forall (m :: * -> *) a. MonadGen m => (a -> [a]) -> m a -> m a
shrink forall a. [a] -> [[a]]
Shrink.list forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a.
Applicative m =>
(a -> m Bool) -> [a] -> m [a]
filterM (forall a b. a -> b -> a
const forall (m :: * -> *). MonadGen m => m Bool
bool_) [a]
xs

-- | Generates a random subset of a set.
--
--  /This shrinks towards the empty set./
--
subset :: MonadGen m => Set a -> m (Set a)
-- Set.fromDistinctAscList has an unchecked precondition that the list
-- must be strictly ascending. This precondition is satisfied because
-- Set.toAscList produces a strictly ascending list, and the 'subsequence'
-- generator only removes elements from the list; it never adds or
-- rearranges elements, so the strictly ascending property is undisturbed.
subset :: forall (m :: * -> *) a. MonadGen m => Set a -> m (Set a)
subset =
  forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall a. [a] -> Set a
Set.fromDistinctAscList forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. MonadGen m => [a] -> m [a]
subsequence forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Set a -> [a]
Set.toAscList

-- | Generates a random permutation of a list.
--
--   /This shrinks towards the order of the list being identical to the input/
--   /list./
--
shuffle :: MonadGen m => [a] -> m [a]
-- We shuffle sequences instead of lists to make extracting an arbitrary
-- element logarithmic instead of linear, and to make length calculation
-- constant-time instead of linear. We could probably do better, but
-- this is at least reasonably quick.
shuffle :: forall (m :: * -> *) a. MonadGen m => [a] -> m [a]
shuffle = forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall (t :: * -> *) a. Foldable t => t a -> [a]
toList forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. MonadGen m => Seq a -> m (Seq a)
shuffleSeq forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. [a] -> Seq a
Seq.fromList

-- | Generates a random permutation of a sequence.
--
--   /This shrinks towards the order of the sequence being identical to the input/
--   /sequence./
--
shuffleSeq :: MonadGen m => Seq a -> m (Seq a)
shuffleSeq :: forall (m :: * -> *) a. MonadGen m => Seq a -> m (Seq a)
shuffleSeq Seq a
xs =
  if forall (t :: * -> *) a. Foldable t => t a -> Bool
null Seq a
xs then
    forall (f :: * -> *) a. Applicative f => a -> f a
pure forall a. Seq a
Seq.empty
  else do
    Int
n <- forall (m :: * -> *) a. (MonadGen m, Integral a) => Range a -> m a
integral forall a b. (a -> b) -> a -> b
$ forall a. a -> a -> Range a
Range.constant Int
0 (forall (t :: * -> *) a. Foldable t => t a -> Int
length Seq a
xs forall a. Num a => a -> a -> a
- Int
1)
#if MIN_VERSION_containers(0,5,8)
    -- Data.Sequence should offer a version of deleteAt that returns the
    -- deleted element, but it does not currently do so. Lookup followed
    -- by deletion seems likely faster than splitting and then appending,
    -- but I haven't actually tested that. It's certainly easier to see
    -- what's going on.
    case forall a. Int -> Seq a -> Maybe a
Seq.lookup Int
n Seq a
xs of
      Just a
y ->
        (a
y forall a. a -> Seq a -> Seq a
Seq.<|) forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *) a. MonadGen m => Seq a -> m (Seq a)
shuffleSeq (forall a. Int -> Seq a -> Seq a
Seq.deleteAt Int
n Seq a
xs)
      Maybe a
Nothing ->
        forall a. HasCallStack => String -> a
error String
"Hedgehog.Gen.shuffleSeq: internal error, lookup in empty sequence"
#else
    case Seq.splitAt n xs of
      (beginning, end) ->
        case Seq.viewl end of
          y Seq.:< end' ->
            (y Seq.<|) <$> shuffleSeq (beginning Seq.>< end')
          Seq.EmptyL ->
            error "Hedgehog.Gen.shuffleSeq: internal error, lookup in empty sequence"
#endif

------------------------------------------------------------------------
-- Sampling

-- | Generate a sample from a generator.
--
sample :: MonadIO m => Gen a -> m a
sample :: forall (m :: * -> *) a. MonadIO m => Gen a -> m a
sample Gen a
gen =
  forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO forall a b. (a -> b) -> a -> b
$
    let
      loop :: Int -> IO a
loop Int
n =
        if Int
n forall a. Ord a => a -> a -> Bool
<= Int
0 then
          forall a. HasCallStack => String -> a
error String
"Hedgehog.Gen.sample: too many discards, could not generate a sample"
        else do
          Seed
seed <- forall (m :: * -> *). MonadIO m => m Seed
Seed.random
          case forall a. Size -> Seed -> Gen a -> Maybe (Tree a)
evalGen Size
30 Seed
seed Gen a
gen of
            Maybe (Tree a)
Nothing ->
              Int -> IO a
loop (Int
n forall a. Num a => a -> a -> a
- Int
1)
            Just Tree a
x ->
              forall (f :: * -> *) a. Applicative f => a -> f a
pure forall a b. (a -> b) -> a -> b
$ forall a. Tree a -> a
Tree.treeValue Tree a
x
    in
      Int -> IO a
loop (Int
100 :: Int)

-- | Run a generator with a random seed and print the outcome, and the first
--   level of shrinks.
--
-- @
-- Gen.print (Gen.'enum' \'a\' \'f\')
-- @
--
--   > === Outcome ===
--   > 'd'
--   > === Shrinks ===
--   > 'a'
--   > 'b'
--   > 'c'
--
print :: (MonadIO m, Show a) => Gen a -> m ()
print :: forall (m :: * -> *) a. (MonadIO m, Show a) => Gen a -> m ()
print Gen a
gen = do
  Seed
seed <- forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO forall (m :: * -> *). MonadIO m => m Seed
Seed.random
  forall (m :: * -> *) a.
(MonadIO m, Show a) =>
Size -> Seed -> Gen a -> m ()
printWith Size
30 Seed
seed Gen a
gen

-- | Print the value produced by a generator, and the first level of shrinks,
--   for the given size and seed.
--
--   Use 'print' to generate a value from a random seed.
--
printWith :: (MonadIO m, Show a) => Size -> Seed -> Gen a -> m ()
printWith :: forall (m :: * -> *) a.
(MonadIO m, Show a) =>
Size -> Seed -> Gen a -> m ()
printWith Size
size Seed
seed Gen a
gen =
  forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO forall a b. (a -> b) -> a -> b
$ do
    case forall a. Size -> Seed -> Gen a -> Maybe (Tree a)
evalGen Size
size Seed
seed Gen a
gen of
      Maybe (Tree a)
Nothing -> do
        String -> IO ()
putStrLn String
"=== Outcome ==="
        String -> IO ()
putStrLn String
"<discard>"

      Just Tree a
tree_ -> do
        let
          NodeT a
x [Tree a]
ss =
            forall a. Identity a -> a
runIdentity (forall (m :: * -> *) a. TreeT m a -> m (NodeT m a)
runTreeT Tree a
tree_)

        String -> IO ()
putStrLn String
"=== Outcome ==="
        String -> IO ()
putStrLn (forall a. Show a => a -> String
show a
x)
        String -> IO ()
putStrLn String
"=== Shrinks ==="

        forall (t :: * -> *) (f :: * -> *) a b.
(Foldable t, Applicative f) =>
t a -> (a -> f b) -> f ()
for_ [Tree a]
ss forall a b. (a -> b) -> a -> b
$ \Tree a
s ->
          let
            NodeT a
y [Tree a]
_ =
              forall a. Identity a -> a
runIdentity forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. TreeT m a -> m (NodeT m a)
runTreeT Tree a
s
          in
            String -> IO ()
putStrLn (forall a. Show a => a -> String
show a
y)

-- | Run a generator with a random seed and print the resulting shrink tree.
--
-- @
-- Gen.printTree (Gen.'enum' \'a\' \'f\')
-- @
--
--   > 'd'
--   >  ├╼'a'
--   >  ├╼'b'
--   >  │  └╼'a'
--   >  └╼'c'
--   >     ├╼'a'
--   >     └╼'b'
--   >        └╼'a'
--
--   /This may not terminate when the tree is very large./
--
printTree :: (MonadIO m, Show a) => Gen a -> m ()
printTree :: forall (m :: * -> *) a. (MonadIO m, Show a) => Gen a -> m ()
printTree Gen a
gen = do
  Seed
seed <- forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO forall (m :: * -> *). MonadIO m => m Seed
Seed.random
  forall (m :: * -> *) a.
(MonadIO m, Show a) =>
Size -> Seed -> Gen a -> m ()
printTreeWith Size
30 Seed
seed Gen a
gen

-- | Print the shrink tree produced by a generator, for the given size and
--   seed.
--
--   Use 'printTree' to generate a value from a random seed.
--
printTreeWith :: (MonadIO m, Show a) => Size -> Seed -> Gen a -> m ()
printTreeWith :: forall (m :: * -> *) a.
(MonadIO m, Show a) =>
Size -> Seed -> Gen a -> m ()
printTreeWith Size
size Seed
seed Gen a
gen = do
  forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO forall b c a. (b -> c) -> (a -> b) -> a -> c
. String -> IO ()
putStr forall a b. (a -> b) -> a -> b
$
    forall a. Show a => Size -> Seed -> Gen a -> String
renderTree Size
size Seed
seed Gen a
gen

-- | Render the shrink tree produced by a generator, for the given size and
--   seed.
--
renderTree :: Show a => Size -> Seed -> Gen a -> String
renderTree :: forall a. Show a => Size -> Seed -> Gen a -> String
renderTree Size
size Seed
seed Gen a
gen =
  case forall a. Size -> Seed -> Gen a -> Maybe (Tree a)
evalGen Size
size Seed
seed Gen a
gen of
    Maybe (Tree a)
Nothing ->
      String
"<discard>"
    Just Tree a
x ->
      Tree String -> String
Tree.render (forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall a. Show a => a -> String
show Tree a
x)

------------------------------------------------------------------------
-- Internal

-- $internal
--
-- These functions are exported in case you need them in a pinch, but are not
-- part of the public API and may change at any time, even as part of a minor
-- update.