Hi,

call-with-port is a standard scheme function, just like
call-with-input-file or call-with-output-file. So, in scheme mode, it
should be indented and fontified similarly.

For the indentation, the 'scheme-indent-function property of
'call-with-port should be set to 1. I don't know how to achieve the
fontification, however.

Thanks!
Arun