Use case for dependencies

[khinsen]

The guide for migration from PetitParser says "I am not aware of any use-case for dependencies, so I didn’t migrated the functionality." I think I have just hit such a use case, which I will summarize below. If there is a good way to deal with this in PetitParser2, I'd appreciate suggestions.

I have a grammar for "terms" in my language, and also a parser that generates the internal representation, implemented as a subclass, exactly like in the example from the tutorial. My plan is to have another subclass of the grammar for implementing syntax highlighting by generating "roped text" objects for use in Bloc (inside Glamorous Toolkit). So far, no problem.

But I also have higher-level syntactic structures that contain terms. This is where I would use dependencies in PetitParser. Without dependencies, I had to use subclassing (example) to include my term parser into my rule parser. But that means I cannot have a separate grammar for my rules, which I could then also use for syntax highlighting. I can use subclassing either for specializing a grammar to a parser, or for extending a parser to a higher-level syntactic structure, but not for both.