https://github.com/akkartik/mu/blob/master/continuation3.mu

     1 # Example program showing that a function call can be 'paused' multiple times,
     2 # creating different continuation values.
     3 #
     4 # To run:
     5 #   $ git clone https://github.com/akkartik/mu
     6 #   $ cd mu
     7 #   $ ./mu continuation3.mu
     8 #
     9 # Expected output:
    10 #   caller 0
    11 #   callee 0
    12 #   caller 1
    13 #   callee 1
    14 #   caller 2
    15 #   callee 2
    16
    17 def main [
    18   local-scope
    19   $print [caller 0] 10/newline
    20   k:continuation <- call-with-continuation-mark 100/mark, f
    21   $print [caller 1] 10/newline
    22   k <- call k
    23   $print [caller 2] 10/newline
    24   call k
    25 ]
    26
    27 def f [
    28   local-scope
    29   $print [callee 0] 10/newline
    30   return-continuation-until-mark 100/mark
    31   $print [callee 1] 10/newline
    32   return-continuation-until-mark 100/mark
    33   $print [callee 2] 10/newline
    34 ]