    {-# LANGUAGE DeriveDataTypeable #-}
    {-# LANGUAGE DeriveGeneric #-}
    {-# 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,
      BooleanFlag(..) ) where

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

    -- ------------------------------------------------------------
    -- * 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.
    --
    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
    /= :: Flag a -> Flag a -> Bool
    $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
    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
    $cto :: forall a x. Rep (Flag a) x -> Flag a
    $cfrom :: forall a x. Flag a -> Rep (Flag a) x
    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
    showList :: [Flag a] -> ShowS
    $cshowList :: forall a. Show a => [Flag a] -> ShowS
    show :: Flag a -> String
    $cshow :: forall a. Show a => Flag a -> String
    showsPrec :: Int -> Flag a -> ShowS
    $cshowsPrec :: forall a. Show a => Int -> 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
    readListPrec :: ReadPrec [Flag a]
    $creadListPrec :: forall a. Read a => ReadPrec [Flag a]
    readPrec :: ReadPrec (Flag a)
    $creadPrec :: forall a. Read a => ReadPrec (Flag a)
    readList :: ReadS [Flag a]
    $creadList :: forall a. Read a => ReadS [Flag a]
    readsPrec :: Int -> ReadS (Flag a)
    $creadsPrec :: forall a. Read a => Int -> ReadS (Flag a)
    Read, Typeable)

    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
    _        = []

    toFlag :: a -> Flag a
    toFlag :: forall a. a -> Flag a
    toFlag = a -> Flag a
    forall a. a -> Flag a
    Flag

    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"

    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

    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

    -- | @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

    flagToList :: Flag a -> [a]
    flagToList :: forall a. Flag a -> [a]
    flagToList (Flag a
    x) = [a
    x]
    flagToList Flag a
    NoFlag   = []

    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

    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

    -- | 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