47 lines
1.2 KiB
C
47 lines
1.2 KiB
C
/* vi: set sw=4 ts=4 :
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* llist.c - Linked list functions
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*
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* Linked list structures have a next pointer as their first element.
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*/
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#include "toys.h"
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// Free all the elements of a linked list
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// if freeit!=NULL call freeit() on each element before freeing it.
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void llist_free(void *list, void (*freeit)(void *data))
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{
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while (list) {
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void *pop = llist_pop(&list);
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if (freeit) freeit(pop);
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}
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}
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// Return the first item from the list, advancing the list (which must be called
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// as &list)
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void *llist_pop(void *list)
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{
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// I'd use a void ** for the argument, and even accept the typecast in all
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// callers as documentation you need the &, except the stupid compiler
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// would then scream about type-punned pointers. Screw it.
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void **llist = (void **)list;
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void **next = (void **)*llist;
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*llist = *next;
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return (void *)next;
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}
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// Add an entry to the end off a doubly linked list
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void dlist_add(struct double_list **list, char *data)
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{
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struct double_list *line = xmalloc(sizeof(struct double_list));
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line->data = data;
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if (*list) {
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line->next = *list;
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line->prev = (*list)->prev;
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(*list)->prev->next = line;
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(*list)->prev = line;
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} else *list = line->next = line->prev = line;
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}
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