Scala Macro Annotations: c.TypeCheck of annotated type causes StackOverflowError

Question

I have a macro annotation which is intended to be applied to class definitions. Its purpose is an almost-but-not-quite serialization tool. It inspects the class\'s constru

Answer 1

This seems to be quite related to the discussion started in Can't access Parent's Members while dealing with Macro Annotations (also see a link to a more lengthy elaboration in my answer over there).

If possible I would like to avoid situations when macros see half-expanded or half-populated types in order to reduce the potential for confusion. Last months I've been thinking about ways to avoid that, but there's been a number of higher-priority distractions, so I haven't gotten far yet.

Two potential ideas that I'm pondering are: 1) come up with a notation to specify effects of macro annotations, so that we don't have to expand macros in order to know what classes and members comprise our program (if that works out, then the macro engine can first precompute the list of members and only then launch macro expansions), 2) figure out a mechanism of specifying how macros depend on program elements, so that expansions are ordered correctly. Just yesterday I've also learned about Backstage Java and David Herman's work on typed hygienic macros - this should also be relevant. What do you think about these directions of thought?

In the meanwhile, while I'm trying to figure out a principled solution to the problem of dependencies, I'm also interested in unblocking your use case by providing a workaround or a patch to paradise that would be immediately useful. Could you elaborate on your project, so that we could come up with a fix?