Double Ended Queue

Implementation if a double ended queue data structure for generic pointers. More...

Typedefs
typedef int(*	cmp_fun )(const void *elem, const void *key)
	The type of the pointer compare function. More...
typedef struct pdeq	pdeq
	The pointer double ended queue (list). More...

Functions
pdeq *	new_pdeq (void)
	Creates a new double ended pointer list. More...
void	del_pdeq (pdeq *dq)
	Delete a double ended pointer list. More...
size_t	pdeq_len (pdeq const *dq)
	Returns the length of a double ended pointer list. More...
int	pdeq_empty (pdeq const *dq)
	Checks if a list is empty. More...
int	pdeq_contains (pdeq const *dq, const void *x)
	Returns non-zero if a double ended pointer list contains a pointer x. More...
void *	pdeq_search (pdeq const *qp, cmp_fun cmp, const void *key)
	Search a key in a double ended pointer list, the search is controlled by a compare function. More...
void **	pdeq_copyl (const pdeq *qp, const void **dst)
	Convert the double ended pointer list into a linear array beginning from left, the first element in the linear array will be the left one. More...
void **	pdeq_copyr (const pdeq *qp, const void **dst)
	Convert the double ended pointer list into a linear array beginning from right, the first element in the linear array will be the right one. More...
pdeq *	pdeq_putl (pdeq *dq, const void *x)
	Add a pointer to the left side of a double ended pointer list. More...
pdeq *	pdeq_putr (pdeq *dq, const void *x)
	Add a pointer to the right side of a double ended pointer list. More...
void *	pdeq_getl (pdeq *dq)
	Retrieve (and remove) a pointer from the left site of a double ended pointer list. More...
void *	pdeq_getr (pdeq *dq)
	Retrieve (and remove) a pointer from the right site of a double ended pointer list. More...

Detailed Description

Implementation if a double ended queue data structure for generic pointers.

Typedef Documentation

typedef int(* cmp_fun)(const void *elem, const void *key)

The type of the pointer compare function.

Parameters

elem	The list element.
key	The user supplied key.

Returns

0 if the element matches the key, non-zero else.

Definition at line 33 of file pdeq.h.

typedef struct pdeq pdeq

The pointer double ended queue (list).

Definition at line 38 of file pdeq.h.

Function Documentation

void del_pdeq

(

pdeq *

dq

)

Delete a double ended pointer list.

Parameters

dq	The list to be deleted.

pdeq* new_pdeq

(

void

)

Creates a new double ended pointer list.

Returns

A new list.

int pdeq_contains	(	pdeq const *	dq,
		const void *	x
	)

Returns non-zero if a double ended pointer list contains a pointer x.

Parameters

dq	The list.
x	The pointer to be searched for.

void** pdeq_copyl	(	const pdeq *	qp,
		const void **	dst
	)

Convert the double ended pointer list into a linear array beginning from left, the first element in the linear array will be the left one.

Parameters

qp	The list.
dst	A pointer to a pointer array with must be at least pdeq_len(dq) * sizeof(void *)

Returns

dst

void** pdeq_copyr	(	const pdeq *	qp,
		const void **	dst
	)

Convert the double ended pointer list into a linear array beginning from right, the first element in the linear array will be the right one.

Parameters

qp	The list.
dst	A pointer to a pointer array with must be at least pdeq_len(dq) * sizeof(void *)

Returns

dst

int pdeq_empty

(

pdeq const *

dq

)

Checks if a list is empty.

Parameters

dq

The list.

Returns

non-zero if the list is empty.

void* pdeq_getl

(

pdeq *

dq

)

Retrieve (and remove) a pointer from the left site of a double ended pointer list.

Parameters

dq

The list

Returns

The pointer element.

Remarks

This function will fail if the list is empty.

void* pdeq_getr

(

pdeq *

dq

)

Retrieve (and remove) a pointer from the right site of a double ended pointer list.

Parameters

dq

The list

Returns

The pointer element.

Remarks

This function will fail if the list is empty.

size_t pdeq_len

(

pdeq const *

dq

)

Returns the length of a double ended pointer list.

Parameters

dq

The list.

pdeq* pdeq_putl	(	pdeq *	dq,
		const void *	x
	)

Add a pointer to the left side of a double ended pointer list.

Parameters

dq	The list to add a pointer to.
x	The pointer element to be added

Returns

The list.

pdeq* pdeq_putr	(	pdeq *	dq,
		const void *	x
	)

Add a pointer to the right side of a double ended pointer list.

Parameters

dq	The list to add a pointer to.
x	The pointer element to be added

Returns

The list.

void* pdeq_search	(	pdeq const *	qp,
		cmp_fun	cmp,
		const void *	key
	)

Search a key in a double ended pointer list, the search is controlled by a compare function.

An element is found, if the compare function returns 0. The search is started from the left site of the list.

Parameters

qp	The list.
cmp	The compare function.
key	The search key.

Returns

The address of the element entry if the key was found, NULL else.