> s
(1 . #<promise>)
> (tail s)
(2 . #<promise>)
> (tail (tail s))
(3 . #<promise>)
> (tail (tail (tail s)))
()
[image] [image] x: undefined;
 cannot reference an identifier before its definition
[image] [image] x: undefined;
 cannot reference an identifier before its definition
> (my-force (my-delay (+ 2 3)))
5
> (my-force (my-delay (/ 2 0)))
[image] [image] /: division by zero
> (my-delay (/ 2 0))
[image] [image] /: division by zero
> (delay (/ 2 0))
#<promise>
> (my-delay (/ 2 0))
#<procedure>
> (my-force (my-delay (/ 2 0)))
[image] [image] /: division by zero
> 
> s2
(2 . #<promise>)
> (tail s2)
[image] [image] x: undefined;
 cannot reference an identifier before its definition
> (define x 5)
> (tail s2)
(5 . #<promise>)
> (enum 1 10)
(1 . #<promise>)
> (enum 1 100)
(1 . #<promise>)
> (enum 1 (fact 30000))
(1 . #<promise>)
> (define bigs (enum 1 (fact 30000)))
> (tail (tail (tail bigs)))
(4 . #<promise>)
> (define bigs (enum 1 (fact 30000)))
> (take 10 bigs)
(1 2 3 4 5 6 7 8 9 10)
>