Linked list library
[Libraries]

The linked list library provides a set of functions for manipulating linked lists. More...

Files
file	list.c
	Linked list library implementation.
file	list.h
	Linked list manipulation routines.
Defines
#define	LIST(name)
	Declare a linked list.
#define	LIST_STRUCT(name)
	Declare a linked list inside a structure declaraction.
#define	LIST_STRUCT_INIT(struct_ptr, name)
	Initialize a linked list that is part of a structure.
Typedefs
typedef void **	list_t
	The linked list type.
Functions
void	list_init (list_t list)
	Initialize a list.
void *	list_head (list_t list)
	Get a pointer to the first element of a list.
void	list_copy (list_t dest, list_t src)
	Duplicate a list.
void *	list_tail (list_t list)
	Get the tail of a list.
void	list_add (list_t list, void *item)
	Add an item at the end of a list.
void	list_push (list_t list, void *item)
	Add an item to the start of the list.
void *	list_chop (list_t list)
	Remove the last object on the list.
void *	list_pop (list_t list)
	Remove the first object on a list.
void	list_remove (list_t list, void *item)
	Remove a specific element from a list.
int	list_length (list_t list)
	Get the length of a list.
void	list_insert (list_t list, void previtem, void newitem)
	Insert an item after a specified item on the list.
void *	list_item_next (void *item)
	Get the next item following this item.

Detailed Description

The linked list library provides a set of functions for manipulating linked lists.

A linked list is made up of elements where the first element must be a pointer. This pointer is used by the linked list library to form lists of the elements.

Lists are declared with the LIST() macro. The declaration specifies the name of the list that later is used with all list functions.

Lists can be manipulated by inserting or removing elements from either sides of the list (list_push(), list_add(), list_pop(), list_chop()). A specified element can also be removed from inside a list with list_remove(). The head and tail of a list can be extracted using list_head() and list_tail(), respectively.

Define Documentation

#define LIST ( name )

Value:

static void *LIST_CONCAT(name,_list) = NULL; \
         static list_t name = (list_t)&LIST_CONCAT(name,_list)

Declare a linked list.

This macro declares a linked list with the specified type. The type must be a structure (struct) with its first element being a pointer. This pointer is used by the linked list library to form the linked lists.

The list variable is declared as static to make it easy to use in a single C module without unnecessarily exporting the name to other modules.

Parameters:

name

The name of the list.

Examples:: example-list.c, example-multihop.c, and example-runicast.c.

Definition at line 89 of file list.h.

#define LIST_STRUCT ( name )

Value:

void *LIST_CONCAT(name,_list); \
         list_t name

Declare a linked list inside a structure declaraction.

This macro declares a linked list with the specified type. The type must be a structure (struct) with its first element being a pointer. This pointer is used by the linked list library to form the linked lists.

Internally, the list is defined as two items: the list itself and a pointer to the list. The pointer has the name of the parameter to the macro and the name of the list is a concatenation of the name and the suffix "_list". The pointer must point to the list for the list to work. Thus the list must be initialized before using.

The list is initialized with the LIST_STRUCT_INIT() macro.

Parameters:

name

The name of the list.

Definition at line 111 of file list.h.

#define LIST_STRUCT_INIT	(	struct_ptr,
		name		)

Value:

do {                                                                \
       (struct_ptr)->name = &((struct_ptr)->LIST_CONCAT(name,_list));   \
       (struct_ptr)->LIST_CONCAT(name,_list) = NULL;                    \
       list_init((struct_ptr)->name);                                   \
    } while(0)

Initialize a linked list that is part of a structure.

This macro sets up the internal pointers in a list that has been defined as part of a struct. This macro must be called before using the list.

Parameters:

	struct_ptr	A pointer to the struct
	name	The name of the list.

Definition at line 125 of file list.h.

Function Documentation

void list_add	(	list_t	list,
		void *	item
	)

Add an item at the end of a list.

This function adds an item to the end of the list.

Parameters:

	list	The list.
	item	A pointer to the item to be added.

See also:: list_push()

Examples:: example-list.c, and example-multihop.c.

void * list_chop ( list_t list )

Remove the last object on the list.

This function removes the last object on the list and returns it.

Parameters:

list

The list

Returns:: The removed object

Examples:: example-runicast.c.

void list_copy	(	list_t	dest,
		list_t	src
	)

Duplicate a list.

This function duplicates a list by copying the list reference, but not the elements.

Note:: This function does not copy the elements of the list, but merely duplicates the pointer to the first element of the list.

Parameters:

	dest	The destination list.
	src	The source list.

void * list_head ( list_t list )

Get a pointer to the first element of a list.

This function returns a pointer to the first element of the list. The element will not be removed from the list.

Parameters:

list

The list.

Returns:: A pointer to the first element on the list.

See also:: list_tail()

Examples:: example-list.c, example-multihop.c, and example-runicast.c.

void list_init ( list_t list )

Initialize a list.

This function initalizes a list. The list will be empty after this function has been called.

Parameters:

list

The list to be initialized.

Examples:: example-list.c, example-multihop.c, and example-runicast.c.

void list_insert	(	list_t	list,
		void *	previtem,
		void *	newitem
	)

Insert an item after a specified item on the list.

Parameters:

	list	The list
	previtem	The item after which the new item should be inserted
	newitem	The new item that is to be inserted

Author:: Adam Dunkels

This function inserts an item right after a specified item on the list. This function is useful when using the list module to ordered lists.

If previtem is NULL, the new item is placed at the start of the list.

void * list_item_next ( void * item )

Get the next item following this item.

Parameters:

item

A list item

Returns:: A next item on the list

This function takes a list item and returns the next item on the list, or NULL if there are no more items on the list. This function is used when iterating through lists.

Examples:: example-list.c.

int list_length ( list_t list )

Get the length of a list.

This function counts the number of elements on a specified list.

Parameters:

list

The list.

Returns:: The length of the list.

Examples:: example-multihop.c.

void * list_pop ( list_t list )

Remove the first object on a list.

This function removes the first object on the list and returns a pointer to it.

Parameters:

list

The list.

Returns:: Pointer to the removed element of list.

void list_remove	(	list_t	list,
		void *	item
	)

Remove a specific element from a list.

This function removes a specified element from the list.

Parameters:

	list	The list.
	item	The item that is to be removed from the list.

Examples:: example-multihop.c.

void * list_tail ( list_t list )

Get the tail of a list.

This function returns a pointer to the elements following the first element of a list. No elements are removed by this function.

Parameters:

list

The list

Returns:: A pointer to the element after the first element on the list.

See also:: list_head()

Linked list library [Libraries]

Files

Defines

Typedefs

Functions

Detailed Description

Define Documentation

Function Documentation

Linked list library
[Libraries]