[plt-scheme] parser-tools

>  NOTE: Since the lexer gets its source information from the port, use
>  port-count-lines! to enable the tracking of line and column information.
>  Otherwise the line and column information will return #f.
> 
> 
>  The lexer gets the line and column information directly from the port.  By 
>  default the port doesn't keep track of this information (presumably for 
>  efficiency reasons).  If you call port-count-lines! on the port before 
>  lexing it, then you should get the information you want.  See 11.2.1.1 of 
>  the MzScheme manual.

Excellent, thanks so much for the help