+ (let ((entities '())
+ (components '())
+ (key #f))
+ (receive (e c k) ((new-entity (make-a 1 2) (make-b)) entities components)
+ (set! entities e)
+ (set! components c)
+ (set! key k)
+ (display k) (newline))
+ (format #t "New entity with a and b:~%~a~%~a~%~%" entities components)
+
+ (receive (e c k) ((new-entity (make-a 10 20)) entities components)
+ (set! entities e)
+ (set! components c)
+ (display k) (newline))
+ (format #t "New entity with a:~%~a~%~a~%~%" entities components)
+
+ (receive (e c) (modify-entities (list (set-entity-components key (make-a 50 50)) (remove-entity-components key 'b)) entities components)
+ (set! entities e)
+ (set! components c))
+ (format #t "First entity removes b and changes a:~%~a~%~a~%~%" entities components)
+
+ (receive (e c) ((remove-entity key) entities components)
+ (set! entities e)
+ (set! components c))
+ (format #t "Removes first entity:~%~a~%~a~%~%" entities components)
+
+ (receive (e c k) ((new-entity (make-a 1 2) (make-b)) entities components)
+ (set! entities e)
+ (set! components c)
+ (set! key k)
+ (display k) (newline))
+ (format #t "New entity with a and b:~%~a~%~a~%~%" entities components)
+
+ (receive (e c) (modify-entities (list (set-entity-components key (make-a 50 50)) (remove-entity-components key 'b) (new-entity (make-a 1000 1000))) entities components)
+ (set! entities e)
+ (set! components c))
+ (format #t "Last entity removes b and changes a, and new entity with a:~%~a~%~a~%~%" entities components)
+
+ (receive (e c) (modify-entities (list (remove-entity key)) entities components)
+ (set! entities e)
+ (set! components c))
+ (format #t "Remove last entity:~%~a~%~a~%~%" entities components)
+))
+
+(export test1)
+
+
+(define (test2)