Add tasks for all the new languages

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))

Task/Queue-Definition/XLISP/queue-definition-2.xlisp

@@ -0,0 +1,24 @@
+[1] (define my-queue (queue 'new))
+
+MY-QUEUE
+[2] (my-queue 'push 1)
+
+(1)
+[3] (my-queue 'push 2)
+
+(1 2)
+[4] (my-queue 'emptyp)
+
+()
+[5] (my-queue 'pop)
+
+1
+[6] (my-queue 'pop)
+
+2
+[7] (my-queue 'emptyp)
+
+#T
+[8] (my-queue 'pop)
+
+()