- read-with-source-info #!optional portprocedure
Exactly like {read} from the {scheme} module, except it registers the expression it read into the line number database, so that if {(read-with-source-info)} returns {OBJ}, {(get-line-number OBJ)} will return the line number in {port}.
The port argument may be omitted, in which case it defaults to the value returned by current-input-port. It is an error to read from a closed port.