4.1. Overriding Interchange Routines

Many of the internal Interchange routines can be accessed by programmers who can read the source and find entry points. Also, many internal Interchange routines can be overridden:

   GlobalSub <<EOS
   sub just_for_overriding {
       package Vend::Module;
       use MyModule;
       sub to_override {

The effect of the above code is to override the to_override routine in the module Vend::Module. This is preferable to hacking the code for functionality changes that are not expected to change frequently. In most cases, updating the Interchange code will not affect the overridden code.

Note: Internal entry points are not guaranteed to exist in future versions of Interchange.