A printer callback fucntion is a function can performs the actual
printing. It has a number of subcommands, that are called by
the printer package, in a form
printer_callback("subcommand", argument1, argument2, ...)
See the examples below.
printer_callback(fun)The function to use as a printer callback function.
The subcommands:
lengthThe length of the data to print, the number of items, in natural units. E.g. for a list of objects, it is the number of objects.
min_widthTODO
widthWidth of one item, if no items will be
printed. TODO
printArgument: no. Do the actual printing,
print no items.
doneTODO
Other printer callbacks: is_printer_callback