Add a dynamic data structure example

lisp/random/structure.lisp

@@ -0,0 +1,22 @@
+(load "../lang/dlambda.lisp")
+(load "../lang/functions.lisp")
+
+(define-special keys (&rest fields)
+  (eval
+    (list 'let (mapcar 'list fields)
+      '(eval
+        (dlambda
+          (:get (field) (eval field))
+          (:set (field value) (set field value)))))))
+
+(defun process-data (data)
+  (let ((one (call data :get 'one))
+        (two (call data :get 'two))
+        (three (call data :get 'three)))
+    (list one two three)))
+
+(setq data (keys one two three))
+(call data :set 'one "goodbye")
+(call data :set 'two "key")
+(call data :set 'three "!")
+(process-data data)