Fix refinement variable mapping: '_' and 'return' →

[rajshivu]

Updated CreateASTVisitor to map refinement variables '_' and 'return' to '$result' to prevent conflicts.
Verified by manual test in ReturnRefinementTest.java.

[rcosta358]

Hi @rajshivu,
This is not really what we were looking for. Your approach replaces the variables return and _ with $result, which is incorrect and causes the tests to fail.

To allow $result to represent return values of methods, you need to modify the grammar to allow identifiers to start with $, substitute the variable $result with _ (similarly to return), and finally add some tests to check if your implementation is correct.

[rcosta358]

Also, if you have any suggestions other than $result, which is not very idiomatic for Java, feel free to let us know!

[rajshivu]

Hi @rcosta358 ,
Thank you for the clarification - that makes sense. You’re right, my initial approach was too naive and incorrectly replaced return and _ directly with $result, which explains the failing tests.

Based on your feedback, I understand the correct direction is to:

1. Extend the grammar to allow identifiers starting with $.
2. Treat $result as a syntactic alias and internally substitute it with _ (similarly to how return is handled today).
3. Add proper tests to validate that $result, _, and return behave consistently.

I’ll update the implementation accordingly and push a revised PR.
Also, I agree that $result may not be the most idiomatic Java-style identifier — I’ll think about alternative suggestions and share them if I find a better fit.

Thanks again for the guidance, this was very helpful.