Maybe example

gistfile1.scm

(do <maybe> 
    (if #t 
        'Nothing 
        '(Just First))
    '(Just Second))
; Returns: Nothing

((do <state> 
     (x <- (/m! gets (lambda (s) (+ s 1))))
     (return x))
 1)
; Returns: (2 . 1)

((do <reader> 
     (/m! local 
          (lambda (v) (+ v 1))
            (do <reader> 
                (x <- (/m ask))
                (return x))))
     1)
; Returns: 2