shithub: libds

ref: cfd7660a044c8bd3ad0c33a237155b05248c0b0b
dir: libds/list.c

#include <u.h>
#include <libc.h>
#include "ds.h"
#include "list.h"

// Return an allocated, empty, list. 
List*
mklist(void)
{
	List *l = ecalloc(1, sizeof (List));
	l->size = 0;
	return l;
}

// Prepend to the front of the list. 
List*
listprepend(List *l, void *datum)
{
	if(l == nil)
		// Nil pointer
		return l;

	ListNode *n = ecalloc(1, sizeof (ListNode));

	if(l->head == nil){
		// Empty list, be the head
		l->head = n;
	}else{
		// Replace head
		n->next = l->head;
		l->head = n;
	}

	l->head->datum = datum;
	l->size++;

	return l;
}

// Append to the end of the list. 
List*
listappend(List *l, void *datum)
{
	if(l == nil)
		// Nil pointer
		return l;

	ListNode *n = ecalloc(1, sizeof (ListNode));

	if(l->head == nil){
		// Empty list, be the head
		l->head = n;
	}else{
		// Replace tail
		ListNode *ln;
		for(ln = l->head; ln->next != nil; ln = ln->next)
			;
		ln->next = n;
		n->next = nil;
	}

	n->datum = datum;
	l->size++;

	return l;
}