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Task/Object-serialization/EchoLisp/object-serialization-1.echolisp

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+(define (person->string self) (format "%a : person." (person-name self)))
+(define (writer->string self) (format "%a:  writer of %a."
+			(person-name self)
+			(writer-books self)))
+(define  (father->string self) (format "%a: father of %a."
+			(person-name self)
+			(map person-name (father-children self))))
+			
+; 'classes' definition, with inheritance.
+; a writer is a person, too.
+(struct person (name)  #:tostring person->string)
+(struct writer person (books) #:tostring writer->string)
+(struct father person (children)  #:tostring father->string)
+
+(define simon (writer "Simon" '(my-life my-wife my-bike)))
+(define elvis (person "Elvis"))
+(define papa (father "papa" (list simon elvis)))
+
+(local-put-value 'simon simon "objects.dat")
+📕 local-db: local-put:unknown store : "objects.dat"
+;; forgot to create the store. Create it :
+(local-make-store "objects.dat") → "objects.dat"
+
+(local-put-value 'simon simon "objects.dat")
+(local-put-value 'elvis elvis "objects.dat")
+(local-put-value 'papa papa   "objects.dat")
+
+;; inspect
+simon → Simon: writer of (my-life my-wife my-bike).
+papa → papa: father of (Simon Elvis).
+elvis → Elvis : person.

Task/Object-serialization/EchoLisp/object-serialization-2.echolisp

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+;; reboot (close the browser window)
+; inspect objects.dat :
+(local-keys 'objects.dat) → ("elvis" "papa" "simon")
+
+(define simon (local-get-value 'simon "objects.dat"))
+(define elvis (local-get-value 'elvis "objects.dat"))
+(define papa (local-get-value 'papa "objects.dat"))
+
+; data are restored
+simon → Simon: writer of (my-life my-wife my-bike).
+papa → papa: father of (Simon Elvis).
+
+;; check if references (pointers) are restored
+(set-writer-name! simon "Antoinette") → "Antoinette"
+simon→ Antoinette: writer of (my-life my-wife my-bike).
+
+;; inspect
+papa → papa: father of (Antoinette Elvis). ; YES 😳 !
+
+;; - Self-referencing  (EchoLisp version 2.11)
+;; add 'papa' to the chidren of 'papa' - whatever this means - and print it :
+(set-father-children! papa (list simon papa elvis))
+papa → papa: father of (Antoinette papa Elvis).
+
+; save/restore
+(local-put-value 'papa papa "objects.dat")
+(define papa (local-get-value 'papa "objects.dat"))
+papa → papa: father of (Antoinette papa Elvis).