However, simple annotations are not enough for source-to-source transformations, like the ones performed by HaRe or HasFix.
The reason is that refactorings need to know the exact lexical environment at each point, to avoid name capture when doing renamings or other kind of refactoring.
The library uses open recursion to allow annotating with the current symbol table at each step.
This is cool but doesn't really seem relevant for Disco.