tasks a-s

Task/Queue-Usage/PL-I/queue-usage-1.pli

@@ -0,0 +1,40 @@
+test: proc options (main);
+
+
+   /* To implement a queue. */
+   define structure
+      1 node,
+         2 value fixed,
+         2 link handle(node);
+   declare (head, tail, t) handle (node);
+   declare null builtin;
+   declare i fixed binary;
+
+   head, tail = bind(:node, null:);
+
+   do i = 1 to 10; /* Add ten items to the tail of the queue. */
+      if head = bind(:node, null:) then
+         do;
+            head,tail = new(:node:);
+            get list (head => value);
+            put skip list (head => value);
+            head => link = bind(:node, null:); /* A NULL link */
+         end;
+      else
+         do;
+            t = new(:node:);
+            tail => link = t; /* Point the tail to the new node. */
+            tail = t;
+            tail => link = bind(:node, null:); /* Set the tail link to NULL */
+            get list (tail => value) copy;
+            put skip list (tail => value);
+         end;
+   end;
+
+   /* Pop all the items in the queue. */
+   put skip list ('The queue has:');
+   do while (head ^= bind(:node, null:));
+      put skip list (head => value);
+      head = head => link;
+   end;
+end test;

Task/Queue-Usage/PL-I/queue-usage-2.pli

@@ -0,0 +1,21 @@
+       1
+       3
+       5
+       7
+       9
+      11
+      13
+      15
+      17
+      19
+The queue has:
+       1
+       3
+       5
+       7
+       9
+      11
+      13
+      15
+      17
+      19