{-# LANGUAGE NoImplicitPrelude #-}
{-# OPTIONS_HADDOCK not-home #-}

-- | Maybe type
module GHC.Internal.Maybe
   ( Maybe (..)
   )
where

import GHC.Num.Integer () -- See Note [Depend on GHC.Num.Integer] in GHC.Internal.Base
import GHC.Classes

default ()

-------------------------------------------------------------------------------
-- Maybe type
-------------------------------------------------------------------------------

-- | The 'Maybe' type encapsulates an optional value.  A value of type
-- @'Maybe' a@ either contains a value of type @a@ (represented as @'Just' a@),
-- or it is empty (represented as 'Nothing').  Using 'Maybe' is a good way to
-- deal with errors or exceptional cases without resorting to drastic
-- measures such as 'Prelude.error'.
--
-- The 'Maybe' type is also a monad.  It is a simple kind of error
-- monad, where all errors are represented by 'Nothing'.  A richer
-- error monad can be built using the 'Data.Either.Either' type.
--
data  Maybe a  =  Nothing | Just a
  deriving ( Maybe a -> Maybe a -> Bool
(Maybe a -> Maybe a -> Bool)
-> (Maybe a -> Maybe a -> Bool) -> Eq (Maybe a)
forall a. Eq a => Maybe a -> Maybe a -> Bool
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
$c== :: forall a. Eq a => Maybe a -> Maybe a -> Bool
== :: Maybe a -> Maybe a -> Bool
$c/= :: forall a. Eq a => Maybe a -> Maybe a -> Bool
/= :: Maybe a -> Maybe a -> Bool
Eq  -- ^ @since base-2.01
           , Eq (Maybe a)
Eq (Maybe a) =>
(Maybe a -> Maybe a -> Ordering)
-> (Maybe a -> Maybe a -> Bool)
-> (Maybe a -> Maybe a -> Bool)
-> (Maybe a -> Maybe a -> Bool)
-> (Maybe a -> Maybe a -> Bool)
-> (Maybe a -> Maybe a -> Maybe a)
-> (Maybe a -> Maybe a -> Maybe a)
-> Ord (Maybe a)
Maybe a -> Maybe a -> Bool
Maybe a -> Maybe a -> Maybe a
Maybe a -> Maybe a -> Ordering
forall a.
Eq a =>
(a -> a -> Ordering)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> a)
-> (a -> a -> a)
-> Ord a
forall a. Ord a => Eq (Maybe a)
forall a. Ord a => Maybe a -> Maybe a -> Bool
forall a. Ord a => Maybe a -> Maybe a -> Maybe a
forall a. Ord a => Maybe a -> Maybe a -> Ordering
$ccompare :: forall a. Ord a => Maybe a -> Maybe a -> Ordering
compare :: Maybe a -> Maybe a -> Ordering
$c< :: forall a. Ord a => Maybe a -> Maybe a -> Bool
< :: Maybe a -> Maybe a -> Bool
$c<= :: forall a. Ord a => Maybe a -> Maybe a -> Bool
<= :: Maybe a -> Maybe a -> Bool
$c> :: forall a. Ord a => Maybe a -> Maybe a -> Bool
> :: Maybe a -> Maybe a -> Bool
$c>= :: forall a. Ord a => Maybe a -> Maybe a -> Bool
>= :: Maybe a -> Maybe a -> Bool
$cmax :: forall a. Ord a => Maybe a -> Maybe a -> Maybe a
max :: Maybe a -> Maybe a -> Maybe a
$cmin :: forall a. Ord a => Maybe a -> Maybe a -> Maybe a
min :: Maybe a -> Maybe a -> Maybe a
Ord -- ^ @since base-2.01
           )