[23] DOM support for JEP 476: Module Import Declarations (Preview)

[stephan-herrmann]

• parser to record modifier start position of imports
• avoid code duplication in SourceElementParser
• new list ImportDeclaration.modifiers()
  • at 23 even 'static' is represented in that list
• existing accessors may scan that list if present

fixes https://github.com/eclipse-jdt/eclipse.jdt.core/issues/2834

[stephan-herrmann]

@jarthana while this already produces desired results (and passes even JDT/UI tests), I'm a short in additional tests. From the experience of previous AST additions, can you recommend which test would be good to extend here?

[stephan-herrmann]

Documenting one oddity:

To cleanly separate strategies before vs since JLS23 I had to let JLS23-mode represent all modifiers using list modifiers().

• ASTConverter can use valid source positions (thanks to a small addition in Parser) to create the Modifier instance
• existing clients like CreateImportOperation still want to use setStatic(boolean)
  • in JLS23 mode this now synthesizes a Modifier without source positions

For code manipulation those synthesized Modifiers work fine, we just need to be sure, that setStatic(boolean) is never called in a situation where valid source positions are needed (I made a corresponding note in the method's javadoc).

[stephan-herrmann]

@jarthana while this already produces desired results (and passes even JDT/UI tests), I'm a short in additional tests. From the experience of previous AST additions, can you recommend which test would be good to extend here?

I'm still open to suggestions :)