    {-# LANGUAGE DeriveFoldable #-}
    {-# LANGUAGE DeriveGeneric #-}
    {-# LANGUAGE DeriveTraversable #-}
    {-# LANGUAGE FlexibleContexts #-}

    -----------------------------------------------------------------------------

    -- |
    -- Module      :  Distribution.Simple.Flag
    -- Copyright   :  Isaac Jones 2003-2004
    --                Duncan Coutts 2007
    -- License     :  BSD3
    --
    -- Maintainer  :  cabal-devel@haskell.org
    -- Portability :  portable
    --
    -- Defines the 'Flag' type and it's 'Monoid' instance,  see
    -- <http://www.haskell.org/pipermail/cabal-devel/2007-December/001509.html>
    -- for an explanation.
    --
    -- Split off from "Distribution.Simple.Setup" to break import cycles.
    module Distribution.Simple.Flag
      ( Flag (..)
      , allFlags
      , toFlag
      , fromFlag
      , fromFlagOrDefault
      , flagElim
      , flagToMaybe
      , flagToList
      , maybeToFlag
      , mergeListFlag
      , BooleanFlag (..)
      ) where

    import Distribution.Compat.Prelude hiding (get)
    import Distribution.Compat.Stack
    import Prelude ()

    -- ------------------------------------------------------------

    -- * Flag type

    -- ------------------------------------------------------------

    -- | All flags are monoids, they come in two flavours:
    --
    -- 1. list flags eg
    --
    --   > --ghc-option=foo --ghc-option=bar
    --
    --   gives us all the values ["foo", "bar"]
    --
    -- 2. singular value flags, eg:
    --
    --   > --enable-foo --disable-foo
    --
    --   gives us Just False
    --
    -- So, this 'Flag' type is for the latter singular kind of flag.
    -- Its monoid instance gives us the behaviour where it starts out as
    -- 'NoFlag' and later flags override earlier ones.
    --
    -- Isomorphic to 'Maybe' a.
    data Flag a = Flag a | NoFlag deriving (Flag a -> Flag a -> Bool
    (Flag a -> Flag a -> Bool)
    -> (Flag a -> Flag a -> Bool) -> Eq (Flag a)
    forall a. Eq a => Flag a -> Flag a -> Bool
    forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
    $c== :: forall a. Eq a => Flag a -> Flag a -> Bool
    == :: Flag a -> Flag a -> Bool
    $c/= :: forall a. Eq a => Flag a -> Flag a -> Bool
    /= :: Flag a -> Flag a -> Bool
    Eq, (forall x. Flag a -> Rep (Flag a) x)
    -> (forall x. Rep (Flag a) x -> Flag a) -> Generic (Flag a)
    forall x. Rep (Flag a) x -> Flag a
    forall x. Flag a -> Rep (Flag a) x
    forall a.
    (forall x. a -> Rep a x) -> (forall x. Rep a x -> a) -> Generic a
    forall a x. Rep (Flag a) x -> Flag a
    forall a x. Flag a -> Rep (Flag a) x
    $cfrom :: forall a x. Flag a -> Rep (Flag a) x
    from :: forall x. Flag a -> Rep (Flag a) x
    $cto :: forall a x. Rep (Flag a) x -> Flag a
    to :: forall x. Rep (Flag a) x -> Flag a
    Generic, Int -> Flag a -> ShowS
    [Flag a] -> ShowS
    Flag a -> String
    (Int -> Flag a -> ShowS)
    -> (Flag a -> String) -> ([Flag a] -> ShowS) -> Show (Flag a)
    forall a. Show a => Int -> Flag a -> ShowS
    forall a. Show a => [Flag a] -> ShowS
    forall a. Show a => Flag a -> String
    forall a.
    (Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
    $cshowsPrec :: forall a. Show a => Int -> Flag a -> ShowS
    showsPrec :: Int -> Flag a -> ShowS
    $cshow :: forall a. Show a => Flag a -> String
    show :: Flag a -> String
    $cshowList :: forall a. Show a => [Flag a] -> ShowS
    showList :: [Flag a] -> ShowS
    Show, ReadPrec [Flag a]
    ReadPrec (Flag a)
    Int -> ReadS (Flag a)
    ReadS [Flag a]
    (Int -> ReadS (Flag a))
    -> ReadS [Flag a]
    -> ReadPrec (Flag a)
    -> ReadPrec [Flag a]
    -> Read (Flag a)
    forall a. Read a => ReadPrec [Flag a]
    forall a. Read a => ReadPrec (Flag a)
    forall a. Read a => Int -> ReadS (Flag a)
    forall a. Read a => ReadS [Flag a]
    forall a.
    (Int -> ReadS a)
    -> ReadS [a] -> ReadPrec a -> ReadPrec [a] -> Read a
    $creadsPrec :: forall a. Read a => Int -> ReadS (Flag a)
    readsPrec :: Int -> ReadS (Flag a)
    $creadList :: forall a. Read a => ReadS [Flag a]
    readList :: ReadS [Flag a]
    $creadPrec :: forall a. Read a => ReadPrec (Flag a)
    readPrec :: ReadPrec (Flag a)
    $creadListPrec :: forall a. Read a => ReadPrec [Flag a]
    readListPrec :: ReadPrec [Flag a]
    Read, Typeable, (forall m. Monoid m => Flag m -> m)
    -> (forall m a. Monoid m => (a -> m) -> Flag a -> m)
    -> (forall m a. Monoid m => (a -> m) -> Flag a -> m)
    -> (forall a b. (a -> b -> b) -> b -> Flag a -> b)
    -> (forall a b. (a -> b -> b) -> b -> Flag a -> b)
    -> (forall b a. (b -> a -> b) -> b -> Flag a -> b)
    -> (forall b a. (b -> a -> b) -> b -> Flag a -> b)
    -> (forall a. (a -> a -> a) -> Flag a -> a)
    -> (forall a. (a -> a -> a) -> Flag a -> a)
    -> (forall a. Flag a -> [a])
    -> (forall a. Flag a -> Bool)
    -> (forall a. Flag a -> Int)
    -> (forall a. Eq a => a -> Flag a -> Bool)
    -> (forall a. Ord a => Flag a -> a)
    -> (forall a. Ord a => Flag a -> a)
    -> (forall a. Num a => Flag a -> a)
    -> (forall a. Num a => Flag a -> a)
    -> Foldable Flag
    forall a. Eq a => a -> Flag a -> Bool
    forall a. Num a => Flag a -> a
    forall a. Ord a => Flag a -> a
    forall m. Monoid m => Flag m -> m
    forall a. Flag a -> Bool
    forall a. Flag a -> Int
    forall a. Flag a -> [a]
    forall a. (a -> a -> a) -> Flag a -> a
    forall m a. Monoid m => (a -> m) -> Flag a -> m
    forall b a. (b -> a -> b) -> b -> Flag a -> b
    forall a b. (a -> b -> b) -> b -> Flag 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
    $cfold :: forall m. Monoid m => Flag m -> m
    fold :: forall m. Monoid m => Flag m -> m
    $cfoldMap :: forall m a. Monoid m => (a -> m) -> Flag a -> m
    foldMap :: forall m a. Monoid m => (a -> m) -> Flag a -> m
    $cfoldMap' :: forall m a. Monoid m => (a -> m) -> Flag a -> m
    foldMap' :: forall m a. Monoid m => (a -> m) -> Flag a -> m
    $cfoldr :: forall a b. (a -> b -> b) -> b -> Flag a -> b
    foldr :: forall a b. (a -> b -> b) -> b -> Flag a -> b
    $cfoldr' :: forall a b. (a -> b -> b) -> b -> Flag a -> b
    foldr' :: forall a b. (a -> b -> b) -> b -> Flag a -> b
    $cfoldl :: forall b a. (b -> a -> b) -> b -> Flag a -> b
    foldl :: forall b a. (b -> a -> b) -> b -> Flag a -> b
    $cfoldl' :: forall b a. (b -> a -> b) -> b -> Flag a -> b
    foldl' :: forall b a. (b -> a -> b) -> b -> Flag a -> b
    $cfoldr1 :: forall a. (a -> a -> a) -> Flag a -> a
    foldr1 :: forall a. (a -> a -> a) -> Flag a -> a
    $cfoldl1 :: forall a. (a -> a -> a) -> Flag a -> a
    foldl1 :: forall a. (a -> a -> a) -> Flag a -> a
    $ctoList :: forall a. Flag a -> [a]
    toList :: forall a. Flag a -> [a]
    $cnull :: forall a. Flag a -> Bool
    null :: forall a. Flag a -> Bool
    $clength :: forall a. Flag a -> Int
    length :: forall a. Flag a -> Int
    $celem :: forall a. Eq a => a -> Flag a -> Bool
    elem :: forall a. Eq a => a -> Flag a -> Bool
    $cmaximum :: forall a. Ord a => Flag a -> a
    maximum :: forall a. Ord a => Flag a -> a
    $cminimum :: forall a. Ord a => Flag a -> a
    minimum :: forall a. Ord a => Flag a -> a
    $csum :: forall a. Num a => Flag a -> a
    sum :: forall a. Num a => Flag a -> a
    $cproduct :: forall a. Num a => Flag a -> a
    product :: forall a. Num a => Flag a -> a
    Foldable, Functor Flag
    Foldable Flag
    (Functor Flag, Foldable Flag) =>
    (forall (f :: * -> *) a b.
     Applicative f =>
     (a -> f b) -> Flag a -> f (Flag b))
    -> (forall (f :: * -> *) a.
        Applicative f =>
        Flag (f a) -> f (Flag a))
    -> (forall (m :: * -> *) a b.
        Monad m =>
        (a -> m b) -> Flag a -> m (Flag b))
    -> (forall (m :: * -> *) a. Monad m => Flag (m a) -> m (Flag a))
    -> Traversable Flag
    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 (m :: * -> *) a. Monad m => Flag (m a) -> m (Flag a)
    forall (f :: * -> *) a. Applicative f => Flag (f a) -> f (Flag a)
    forall (m :: * -> *) a b.
    Monad m =>
    (a -> m b) -> Flag a -> m (Flag b)
    forall (f :: * -> *) a b.
    Applicative f =>
    (a -> f b) -> Flag a -> f (Flag b)
    $ctraverse :: forall (f :: * -> *) a b.
    Applicative f =>
    (a -> f b) -> Flag a -> f (Flag b)
    traverse :: forall (f :: * -> *) a b.
    Applicative f =>
    (a -> f b) -> Flag a -> f (Flag b)
    $csequenceA :: forall (f :: * -> *) a. Applicative f => Flag (f a) -> f (Flag a)
    sequenceA :: forall (f :: * -> *) a. Applicative f => Flag (f a) -> f (Flag a)
    $cmapM :: forall (m :: * -> *) a b.
    Monad m =>
    (a -> m b) -> Flag a -> m (Flag b)
    mapM :: forall (m :: * -> *) a b.
    Monad m =>
    (a -> m b) -> Flag a -> m (Flag b)
    $csequence :: forall (m :: * -> *) a. Monad m => Flag (m a) -> m (Flag a)
    sequence :: forall (m :: * -> *) a. Monad m => Flag (m a) -> m (Flag a)
    Traversable)

    instance Binary a => Binary (Flag a)
    instance Structured a => Structured (Flag a)

    instance Functor Flag where
      fmap :: forall a b. (a -> b) -> Flag a -> Flag b
    fmap a -> b
    f (Flag a
    x) = b -> Flag b
    forall a. a -> Flag a
    Flag (a -> b
    f a
    x)
      fmap a -> b
    _ Flag a
    NoFlag = Flag b
    forall a. Flag a
    NoFlag

    instance Applicative Flag where
      (Flag a -> b
    x) <*> :: forall a b. Flag (a -> b) -> Flag a -> Flag b
    <*> Flag a
    y = a -> b
    x (a -> b) -> Flag a -> Flag b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    <$> Flag a
    y
      Flag (a -> b)
    NoFlag <*> Flag a
    _ = Flag b
    forall a. Flag a
    NoFlag
      pure :: forall a. a -> Flag a
    pure = a -> Flag a
    forall a. a -> Flag a
    Flag

    instance Monoid (Flag a) where
      mempty :: Flag a
    mempty = Flag a
    forall a. Flag a
    NoFlag
      mappend :: Flag a -> Flag a -> Flag a
    mappend = Flag a -> Flag a -> Flag a
    forall a. Semigroup a => a -> a -> a
    (<>)

    instance Semigroup (Flag a) where
      Flag a
    _ <> :: Flag a -> Flag a -> Flag a
    <> f :: Flag a
    f@(Flag a
    _) = Flag a
    f
      Flag a
    f <> Flag a
    NoFlag = Flag a
    f

    instance Bounded a => Bounded (Flag a) where
      minBound :: Flag a
    minBound = a -> Flag a
    forall a. a -> Flag a
    toFlag a
    forall a. Bounded a => a
    minBound
      maxBound :: Flag a
    maxBound = a -> Flag a
    forall a. a -> Flag a
    toFlag a
    forall a. Bounded a => a
    maxBound

    instance Enum a => Enum (Flag a) where
      fromEnum :: Flag a -> Int
    fromEnum = a -> Int
    forall a. Enum a => a -> Int
    fromEnum (a -> Int) -> (Flag a -> a) -> Flag a -> Int
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Flag a -> a
    forall a. WithCallStack (Flag a -> a)
    fromFlag
      toEnum :: Int -> Flag a
    toEnum = a -> Flag a
    forall a. a -> Flag a
    toFlag (a -> Flag a) -> (Int -> a) -> Int -> Flag a
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Int -> a
    forall a. Enum a => Int -> a
    toEnum
      enumFrom :: Flag a -> [Flag a]
    enumFrom (Flag a
    a) = (a -> Flag a) -> [a] -> [Flag a]
    forall a b. (a -> b) -> [a] -> [b]
    map a -> Flag a
    forall a. a -> Flag a
    toFlag ([a] -> [Flag a]) -> (a -> [a]) -> a -> [Flag a]
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . a -> [a]
    forall a. Enum a => a -> [a]
    enumFrom (a -> [Flag a]) -> a -> [Flag a]
    forall a b. (a -> b) -> a -> b
    $ a
    a
      enumFrom Flag a
    _ = []
      enumFromThen :: Flag a -> Flag a -> [Flag a]
    enumFromThen (Flag a
    a) (Flag a
    b) = a -> Flag a
    forall a. a -> Flag a
    toFlag (a -> Flag a) -> [a] -> [Flag a]
    forall a b. (a -> b) -> [a] -> [b]
    `map` a -> a -> [a]
    forall a. Enum a => a -> a -> [a]
    enumFromThen a
    a a
    b
      enumFromThen Flag a
    _ Flag a
    _ = []
      enumFromTo :: Flag a -> Flag a -> [Flag a]
    enumFromTo (Flag a
    a) (Flag a
    b) = a -> Flag a
    forall a. a -> Flag a
    toFlag (a -> Flag a) -> [a] -> [Flag a]
    forall a b. (a -> b) -> [a] -> [b]
    `map` a -> a -> [a]
    forall a. Enum a => a -> a -> [a]
    enumFromTo a
    a a
    b
      enumFromTo Flag a
    _ Flag a
    _ = []
      enumFromThenTo :: Flag a -> Flag a -> Flag a -> [Flag a]
    enumFromThenTo (Flag a
    a) (Flag a
    b) (Flag a
    c) = a -> Flag a
    forall a. a -> Flag a
    toFlag (a -> Flag a) -> [a] -> [Flag a]
    forall a b. (a -> b) -> [a] -> [b]
    `map` a -> a -> a -> [a]
    forall a. Enum a => a -> a -> a -> [a]
    enumFromThenTo a
    a a
    b a
    c
      enumFromThenTo Flag a
    _ Flag a
    _ Flag a
    _ = []

    -- | Wraps a value in 'Flag'.
    toFlag :: a -> Flag a
    toFlag :: forall a. a -> Flag a
    toFlag = a -> Flag a
    forall a. a -> Flag a
    Flag

    -- | Extracts a value from a 'Flag', and throws an exception on 'NoFlag'.
    fromFlag :: WithCallStack (Flag a -> a)
    fromFlag :: forall a. WithCallStack (Flag a -> a)
    fromFlag (Flag a
    x) = a
    x
    fromFlag Flag a
    NoFlag = String -> a
    forall a. HasCallStack => String -> a
    error String
    "fromFlag NoFlag. Use fromFlagOrDefault"

    -- | Extracts a value from a 'Flag', and returns the default value on 'NoFlag'.
    fromFlagOrDefault :: a -> Flag a -> a
    fromFlagOrDefault :: forall a. a -> Flag a -> a
    fromFlagOrDefault a
    _ (Flag a
    x) = a
    x
    fromFlagOrDefault a
    def Flag a
    NoFlag = a
    def

    -- | Converts a 'Flag' value to a 'Maybe' value.
    flagToMaybe :: Flag a -> Maybe a
    flagToMaybe :: forall a. Flag a -> Maybe a
    flagToMaybe (Flag a
    x) = a -> Maybe a
    forall a. a -> Maybe a
    Just a
    x
    flagToMaybe Flag a
    NoFlag = Maybe a
    forall a. Maybe a
    Nothing

    -- | Pushes a function through a 'Flag' value, and returns a default
    -- if the 'Flag' value is 'NoFlag'.
    --
    -- @since 3.4.0.0
    flagElim :: b -> (a -> b) -> Flag a -> b
    flagElim :: forall b a. b -> (a -> b) -> Flag a -> b
    flagElim b
    n a -> b
    _ Flag a
    NoFlag = b
    n
    flagElim b
    _ a -> b
    f (Flag a
    x) = a -> b
    f a
    x

    -- | Converts a 'Flag' value to a list.
    flagToList :: Flag a -> [a]
    flagToList :: forall a. Flag a -> [a]
    flagToList (Flag a
    x) = [a
    x]
    flagToList Flag a
    NoFlag = []

    -- | Returns 'True' only if every 'Flag' 'Bool' value is Flag True, else 'False'.
    allFlags :: [Flag Bool] -> Flag Bool
    allFlags :: [Flag Bool] -> Flag Bool
    allFlags [Flag Bool]
    flags =
      if (Flag Bool -> Bool) -> [Flag Bool] -> Bool
    forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Bool
    all (\Flag Bool
    f -> Bool -> Flag Bool -> Bool
    forall a. a -> Flag a -> a
    fromFlagOrDefault Bool
    False Flag Bool
    f) [Flag Bool]
    flags
        then Bool -> Flag Bool
    forall a. a -> Flag a
    Flag Bool
    True
        else Flag Bool
    forall a. Flag a
    NoFlag

    -- | Converts a 'Maybe' value to a 'Flag' value.
    maybeToFlag :: Maybe a -> Flag a
    maybeToFlag :: forall a. Maybe a -> Flag a
    maybeToFlag Maybe a
    Nothing = Flag a
    forall a. Flag a
    NoFlag
    maybeToFlag (Just a
    x) = a -> Flag a
    forall a. a -> Flag a
    Flag a
    x

    -- | Merge the elements of a list 'Flag' with another list 'Flag'.
    mergeListFlag :: Flag [a] -> Flag [a] -> Flag [a]
    mergeListFlag :: forall a. Flag [a] -> Flag [a] -> Flag [a]
    mergeListFlag Flag [a]
    currentFlags Flag [a]
    v =
      [a] -> Flag [a]
    forall a. a -> Flag a
    Flag ([a] -> Flag [a]) -> [a] -> Flag [a]
    forall a b. (a -> b) -> a -> b
    $ [[a]] -> [a]
    forall (t :: * -> *) a. Foldable t => t [a] -> [a]
    concat (Flag [a] -> [[a]]
    forall a. Flag a -> [a]
    flagToList Flag [a]
    currentFlags [[a]] -> [[a]] -> [[a]]
    forall a. [a] -> [a] -> [a]
    ++ Flag [a] -> [[a]]
    forall a. Flag a -> [a]
    flagToList Flag [a]
    v)

    -- | Types that represent boolean flags.
    class BooleanFlag a where
      asBool :: a -> Bool

    instance BooleanFlag Bool where
      asBool :: Bool -> Bool
    asBool = Bool -> Bool
    forall a. a -> a
    id