arraystack.h File Reference

This header file contains the structures and functions needed to work with stacks (implemented using array lists). More...

Typedefs
typedef arraystack_adt *	ArrayStack
	Pointer to structure reprsenting a stack.
Functions
ArrayStack	AS_New ()
	Creates a new stack.
void	AS_Free (ArrayStack stack)
	Destroys the specified stack.
int	AS_Size (ArrayStack stack)
	Returns the size of the stack.
int	AS_Empty (ArrayStack stack)
	Determines if the stack is empty or not.
void	AS_Push (ArrayStack stack, void *el)
	Adds an element to the top of the stack.
void	AS_Pop (ArrayStack stack)
	Removes an element from the top of the stack.
void *	AS_Top (ArrayStack stack)
	Retrieves the data in the element at the top of the stack. The function returns the data in the element at the top of the stack but does not alter in any way the structure of the stack. However the actual data can be changed through the use of the void* pointer returned, which points to the memory location containing the data.

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Detailed Description

This header file contains the structures and functions needed to work with stacks (implemented using array lists).

Author:

Stefan Bucur

It contains functions for creating a stack, destroying it and all the typical operations on a stack (push, pop, top).

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Typedef Documentation

typedef struct arraystack_adt* ArrayStack

Pointer to structure reprsenting a stack.

The ArrayStack is implemented using an ArrayList . However, the underlying ArrayList should not be modified directly but only through the appropriate functions.

As is the case with the ArrayList element data is stored using a void* pointer. Thus, one should note there is no way to tell what kind of data is stored in the list or in a particular element.

See also:

AS_New(), AS_Free(), AS_Pop(), AS_Push(), AS_Top()

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Function Documentation

int AS_Empty

(

ArrayStack

stack

)

Determines if the stack is empty or not.

The function actually returns the value of the expression Size==0.

Parameters:

stack

the stack to be tested.

Returns:

-1 if the stack stack is NULL, 1 if the stack is empty, 0 otherwise.

void AS_Free

(

ArrayStack

stack

)

Destroys the specified stack.

The function frees the memory used by the stack structure itself as well as the memory used by the data in the stack, so trying to access the data after the destruction of the stack (e.g. through a pointer) will most likely result in a Access violation / segfault.

Parameters:

stack

ArrayStack representing the stack to be destroyed.

ArrayStack AS_New

(

)

Creates a new stack.

The function creates a new array stack (stack implemented using an ArrayList ). Thus, the stack can grow to accomodate as many elements as needed.

Returns:

pointer to the newly created stack.

void AS_Pop

(

ArrayStack

stack

)

Removes an element from the top of the stack.

The function removes the element at the top of the stack. Note that the data in that element is not freed, so that it can be further referenced.

Parameters:

stack

the stack on which to perfom the operation

See also:

AS_Top()

void AS_Push	(	ArrayStack	stack,
		void *	el
	)

Adds an element to the top of the stack.

The function adds the data specified by el to the top of the stack.

Parameters:

	stack	the stack to add data to.
	*el	pointer to a initialized memory location containing the data to be added at the top of the stack.

int AS_Size

(

ArrayStack

stack

)

Returns the size of the stack.

The function returns the number of elements in the stack.

Parameters:

stack

stack to be tested.

Returns:

number of elements in stack.

void* AS_Top

(

ArrayStack

stack

)

Retrieves the data in the element at the top of the stack. The function returns the data in the element at the top of the stack but does not alter in any way the structure of the stack. However the actual data can be changed through the use of the void* pointer returned, which points to the memory location containing the data.

Parameters:

stack

the stack on which to perform the operation

Returns:

if stack is NULL or empty, it returns NULL . Otherwise, it returns a pointer to the memory location where the data in the element at the top of the stack is stored.

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