Create a printer callback function
A printer callback fucntion is a function can performs the actual
printing. It has a number of subcommands, that are called by
printer package, in a form
printer_callback("subcommand", argument1, argument2, ...)
See the examples below.
The function to use as a printer callback function.
The 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.
Width of one item, if
noitems will be printed. TODO
no. Do the actual printing, print
Other printer callbacks: