Basic Queue package

1 files changed, 16 insertions, 12 deletions

diff --git a/queue.ads b/queue.ads
index e0da54c..d573490 100644
--- a/queue.ads
+++ b/queue.ads
@@ -1,21 +1,25 @@
 generic
-	type T_Data is limited private;
+	type T_Data is private;
 package Queue is
 
-	type T_Queue is record
-		front: T_List;
-		back:  T_List;
-	end record;
-
-	type T_List_Cell;
-	type T_List is access T_List_Cell;
-	type T_List_Cell is record
+	type T_List_Node;
+	type T_List is access all T_List_Node;
+	type T_List_Node is record
 		data: T_Data;
 		next: T_List;
 	end record;
 
-	procedure Enqueue(queue: T_Queue;
-		              data: T_Data);
-	procedure Dequeue(queue: T_Queue);
+	type T_Queue is record
+		front: T_List := null;
+		back:  T_List := null;
+	end record;
+
+	procedure Enqueue(queue: in out T_Queue; data: T_Data);
+	procedure Dequeue(queue: in out T_Queue);
+	function Length(queue: T_Queue) return Natural;
+
+private
+
+	function Empty(queue: T_Queue) return Boolean;
 
 end Queue;