The following procedures can be used to define a custom printed
representation for an instance. It is highly recommended that instances
be printed by
write-instance-helper, as this ensures a uniform
appearance for all objects.
This is called by the runtime system to generate the printed representation of instance. The methods of this procedure should write the representation to port.
This writes a standardized “frame” for a printed representation method. It generates the following output on port:
where hash-number is the result of calling
instance, and … is the output generated by thunk.