ruby/prism/util/pm_list.h

98 строки
2.4 KiB
C

/**
* @file pm_list.h
*
* An abstract linked list.
*/
#ifndef PRISM_LIST_H
#define PRISM_LIST_H
#include "prism/defines.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
/**
* This struct represents an abstract linked list that provides common
* functionality. It is meant to be used any time a linked list is necessary to
* store data.
*
* The linked list itself operates off a set of pointers. Because the pointers
* are not necessarily sequential, they can be of any size. We use this fact to
* allow the consumer of this linked list to extend the node struct to include
* any data they want. This is done by using the pm_list_node_t as the first
* member of the struct.
*
* For example, if we want to store a list of integers, we can do the following:
*
* ```c
* typedef struct {
* pm_list_node_t node;
* int value;
* } pm_int_node_t;
*
* pm_list_t list = { 0 };
* pm_int_node_t *node = malloc(sizeof(pm_int_node_t));
* node->value = 5;
*
* pm_list_append(&list, &node->node);
* ```
*
* The pm_list_t struct is used to represent the overall linked list. It
* contains a pointer to the head and tail of the list. This allows for easy
* iteration and appending of new nodes.
*/
typedef struct pm_list_node {
/** A pointer to the next node in the list. */
struct pm_list_node *next;
} pm_list_node_t;
/**
* This represents the overall linked list. It keeps a pointer to the head and
* tail so that iteration is easy and pushing new nodes is easy.
*/
typedef struct {
/** The size of the list. */
size_t size;
/** A pointer to the head of the list. */
pm_list_node_t *head;
/** A pointer to the tail of the list. */
pm_list_node_t *tail;
} pm_list_t;
/**
* Returns true if the given list is empty.
*
* @param list The list to check.
* @return True if the given list is empty, otherwise false.
*/
PRISM_EXPORTED_FUNCTION bool pm_list_empty_p(pm_list_t *list);
/**
* Returns the size of the list.
*
* @param list The list to check.
* @return The size of the list.
*/
PRISM_EXPORTED_FUNCTION size_t pm_list_size(pm_list_t *list);
/**
* Append a node to the given list.
*
* @param list The list to append to.
* @param node The node to append.
*/
void pm_list_append(pm_list_t *list, pm_list_node_t *node);
/**
* Deallocate the internal state of the given list.
*
* @param list The list to free.
*/
PRISM_EXPORTED_FUNCTION void pm_list_free(pm_list_t *list);
#endif