I've just come across Jay McCarthy's blog series on continuation marks where he uses this exact problem (keeping track of indentation level) to illustrate the use of dynamic-wind, parameters, and continuation marks.
http://jeapostrophe.github.com/blog/2012/07/16/cont-marks/ http://jeapostrophe.github.com/blog/2012/07/25/cont-marks2/ http://jeapostrophe.github.com/blog/2012/07/30/cont-marks3/ Harry Spier ____________________ Racket Users list: http://lists.racket-lang.org/users
