unicorn/list.c
2016-01-22 19:07:50 -08:00

69 lines
1.5 KiB
C

#include <stdlib.h>
#include <stdint.h>
#include "list.h"
// simple linked list implementation
struct list *list_new(void)
{
return calloc(1, sizeof(struct list));
}
// removed linked list nodes but does not free their content
void list_clear(struct list *list)
{
struct list_item *next, *cur = list->head;
while (cur != NULL) {
next = cur->next;
free(cur);
cur = next;
}
list->head = NULL;
list->tail = NULL;
}
// returns generated linked list node, or NULL on failure
void *list_append(struct list *list, void *data)
{
struct list_item *item = malloc(sizeof(struct list_item));
if (item == NULL) {
return NULL;
}
item->next = NULL;
item->data = data;
if (list->head == NULL) {
list->head = item;
} else {
list->tail->next = item;
}
list->tail = item;
return item;
}
// returns true if entry was removed, false otherwise
bool list_remove(struct list *list, void *data)
{
struct list_item *next, *cur, *prev = NULL;
// is list empty?
if (list->head == NULL) {
return false;
}
cur = list->head;
while (cur != NULL) {
next = cur->next;
if (cur->data == data) {
if (cur == list->head) {
list->head = next;
}
if (cur == list->tail) {
list->tail = prev;
}
free(cur);
return true;
}
prev = cur;
cur = next;
}
return false;
}