libsaria: Create iterators for lists

Not really C++ iterators, but close enough.  I can get the first and
last values values to use in for loops, I also made a next() function
for list items.

Signed-off-by: Bryan Schumaker <bjschuma@gmail.com>

include/libsaria/list.h

@@ -21,6 +21,7 @@ namespace libsaria
 			ListItem(T, List<T> *);
 			~ListItem();
 			T &get_value();
+			ListItem<T> *get_next();
 	};
 
 	template <class T>
@@ -38,6 +39,9 @@ namespace libsaria
 			void erase(ListItem<T> *);
 			unsigned int size();
 
+			ListItem<T> *first();
+			ListItem<T> *last();
+
 			void for_each_item(void (*)(T &, void *), void *);
 			ListItem<T> *find_item(bool (*)(T &, void *), void *);
 	};

libsaria/list/list.cpp

@@ -69,24 +69,32 @@ namespace libsaria
 		return count;
 	}
 
+	template <class T>
+	ListItem<T> *List<T>::first()
+	{
+		return head.next;
+	}
+
+	template <class T>
+	ListItem<T> *List<T>::last()
+	{
+		return &head;
+	}
+
 	template <class T>
 	void List<T>::for_each_item(void (*func)(T &, void *), void *data)
 	{
-		ListItem<T> *item = head.next;
-		while (item != &head) {
-			func(item->value, data);
-			item = item->next;
-		}
+		for (ListItem<T> *it = first(); it != last(); it = it->get_next())
+			func(it->value, data);
 	}
 
 	template <class T>
 	ListItem<T> *List<T>::find_item(bool (*func)(T &, void *), void *data)
 	{
-		ListItem<T> *item = head.next;
-		while (item != &head) {
-			if (func(item->value, data))
+		ListItem<T> *it;
+		for (it = first(); it != last; it = it->get_next()) {
+			if (func(it->value, data))
 				return item;
-			item = item->next;
 		}
 		return NULL;
 	}

libsaria/list/node.cpp

@@ -33,6 +33,12 @@ namespace libsaria
 		return value;
 	}
 
+	template <class T>
+	ListItem<T> *ListItem<T>::get_next()
+	{
+		return next;
+	}
+
 }
 
 #endif /* LIBSARIA_NODE_CPP */