Racket pairs are different from Scheme pairs since Racket pairs are immutable while Scheme pairs are not. As far as I know, there is no way to check for Racket's immutable lists in pure RnRS Scheme. However, it is possible to use Scheme's mutable lists in Racket (though of course...
file,scheme,append,r6rs,ironscheme
IronScheme supports R6RS :) file-options are not available on with-output-to-file, so you need to use open-file-output-port. Example (not correct): (let ((p (open-file-output-port "robot-log.txt" (file-options no-create)))) (fprintf p "~a\r\n" whatToWrite) (close-port p)) Update: The above will not work. It seems you might have found a bug in IronScheme. It is not...