-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Stack data structure type
--   
--   Please see README.md
@package Stack
@version 0.2.0


-- | Abstract Stack data type
--   
--   <a>https://en.wikipedia.org/wiki/Stack_(abstract_data_type)</a>
module Data.Stack

-- | Abstract Stack data type
data Stack a

-- | Create new Stack
stackNew :: Stack a

-- | Push item onto Stack
--   
--   <pre>
--   (∀x)(∀s)(stackPop (stackPush s x) == Just (s,x))
--   </pre>
stackPush :: Stack a -> a -> Stack a

-- | Pop most recently added item without removing from the Stack
--   
--   <pre>
--   stackPeek stackNew == Nothing
--   (∀x)(∀s)(stackPeek (stackPush s x) == Just x)
--   (∀s)(stackPeek s == fmap snd (stackPop s))
--   </pre>
stackPeek :: Stack a -> Maybe a

-- | Pop most recently added item from Stack
--   
--   <pre>
--   stackPop stackNew == Nothing
--   (∀x)(∀s)(stackPop (stackPush s x) == Just (s,x))
--   </pre>
stackPop :: Stack a -> Maybe (Stack a, a)

-- | Test if stack is empty
--   
--   <pre>
--   stackIsEmpty stackNew == True
--   (∀x)(∀s)(stackIsEmpty (stackPush s x) == True)
--   (∀s)((stackSize s == 0) ⇔ (stackIsEmpty s == True))
--   </pre>
stackIsEmpty :: Stack a -> Bool

-- | Compute number of elements contained in the Stack
--   
--   <pre>
--   stackSize stackNew == 0
--   (∀x)(∀s)((stackSize s == n) ⇒ (stackSize (stackPush s x) == n+1))
--   </pre>
stackSize :: Stack a -> Int
instance GHC.Show.Show a => GHC.Show.Show (Data.Stack.Stack a)
instance GHC.Read.Read a => GHC.Read.Read (Data.Stack.Stack a)