macro
boot.janet on line 347, column 1
(prompt tag & body)
Set up a checkpoint that can be returned to. `tag` should be a
value that is used in a `return` statement, like a keyword.
(print
(prompt :a
(for i 0 1000000000000
(print (string "i=" i))
(if (= i 2)
(return :a 10)))))
# output:
# i=0
# i=1
# i=2
# 10