Hi Rodolfo, In this case though, printf will never return #f so "and" is equivalent to "begin", right?
-Joe On Wed, Mar 21, 2012 at 2:30 PM, Rodolfo Carvalho <rhcarva...@gmail.com>wrote: > On Wed, Mar 21, 2012 at 17:21, Joe Gilray <jgil...@gmail.com> wrote: > >> Hi Tim, >> >> Thanks for sharing your code. >> >> Quick, newby question: why do you use "and" instead of "begin" in your >> progress function? >> > > > If you are used to run commands from bash you may do things like > > command1 && command2 && command3 > > e.g.: mkdir somedir && cd somedir && git clone ... > > > Why people do that? Simply put, all of the commands after a `&&' are only > run if the commands before executes fine (return code 0). > So "git clone" will be executed only if I could create a dir and cd to it. > It will not be executed if I don't have permissions to create a dir. > > Using "and" is like using "&&" in bash, while "begin" is equivalent of > separating the commands with ";". > > More on short-circuit evaluation: > http://en.wikipedia.org/wiki/Short-circuit_evaluation > > HTH, > > Rodolfo >
____________________ Racket Users list: http://lists.racket-lang.org/users
