Introduction to shadowop and operator redefinition

This page applies to Harlequin v13.1r0 and later; both Harlequin Core and Harlequin MultiRIP.

It is often useful to be able to change the behavior of an operator or a group of operators. The dynamic binding of names in the PostScript language makes this possible by simple redefinition. However, there are problems with this approach, described in more detail below, which can lead to infinite loops or a job bypassing the redefinition. For this reason the operator, shadowop, has been added to the RIP which allows redefinition of operators (and also replacement of previous redefinitions) without the side-effects of simple redefinition.