Metaprogramming in ObjectScript

You can use indirection :

There were a good article on the topic a few years ago by @Olga Phomina 

Not sure if this is what you're getting at, but one of the most exciting and unique things about ObjectScript is how natural it is to do metaprogramming (in the sense of writing ObjectScript that treats other ObjectScript code as data). Because all of your code is in the database, you can work with it from an object or relational perspective - see the %Dictionary package.

There are to main ways of doing this: generators and projections. A generator produces the actual code that will run for a method or trigger in a class at compile time, typically based on the class definition. A projection adds side effects of compiling/recompiling/deleting the class (e.g., updating a global with metadata about the class, creating + queueing compilation of other classes).

isc.rest has a lots of examples of both of these; here's a representative sample:

%pkg.isc.rest.handlerProjection does a bunch of SQL/object updates to data after compilation

%pkg.isc.rest.handler (which uses that projection) has a CodeMode = objectgenerator method that fails compilation of subclasses if certain methods are not overridden.

%pkg.isc.rest.model.action.projection creates a separate class with dependencies on other classes properly declared and queues it to be compiled. The class created extends %pkg.isc.rest.model.action.handler which defines some methods with CodeMode = objectgenerator, though a separate class does the actual work of code generation.