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Task/Queue-Definition/XLISP/queue-definition-1.xlisp

@@ -0,0 +1,17 @@
+(define-class queue
+    (instance-variables vals))
+
+(define-method (queue 'initialize)
+    (setq vals '())
+    self)
+
+(define-method (queue 'push x)
+    (setq vals (nconc vals (cons x nil))))
+
+(define-method (queue 'pop)
+    (define val (car vals))
+    (setq vals (cdr vals))
+    val)
+
+(define-method (queue 'emptyp)
+    (null vals))