Initial data commit

Task/Queue-Definition/ERRE/queue-definition.erre

@@ -0,0 +1,45 @@
+PROGRAM CLASS_DEMO
+
+CLASS QUEUE
+
+   LOCAL SP
+   LOCAL DIM STACK[100]
+
+   FUNCTION ISEMPTY()
+      ISEMPTY=(SP=0)
+   END FUNCTION
+
+   PROCEDURE INIT
+      SP=0
+   END PROCEDURE
+
+   PROCEDURE POP(->XX)
+      XX=STACK[SP]
+      SP=SP-1
+   END PROCEDURE
+
+   PROCEDURE PUSH(XX)
+      SP=SP+1
+      STACK[SP]=XX
+   END PROCEDURE
+
+END CLASS
+
+NEW PILA:QUEUE
+
+BEGIN
+    PILA_INIT  ! constructor
+    FOR N=1 TO 4 DO  ! push 4 numbers
+       PRINT("Push";N)
+       PILA_PUSH(N)
+    END FOR
+    FOR I=1 TO 5 DO  ! pop 5 numbers
+       IF NOT PILA_ISEMPTY() THEN
+           PILA_POP(->N)
+           PRINT("Pop";N)
+         ELSE
+           PRINT("Queue is empty!")
+       END IF
+    END FOR
+    PRINT("* End *")
+END PROGRAM