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Task/Pointers-and-references/EchoLisp/pointers-and-references.echolisp

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+(define B (box 42))
+    → B ;; box reference
+(unbox B)
+    → 42 ;; box contents
+
+;; sets new value for box contents
+(define ( change-by-ref abox avalue)
+    (set-box! abox avalue) )
+
+(change-by-ref B 666)
+    → #[box 666]
+(unbox B)
+    → 666