Error reporting

[cpfr]

In many cases the exception classes do not receive an ASTNode object, therefore the error reporting can not provide a line number of the error (which is not very helpful in many cases):

ResolveVisitor caught error in null: ...

instead of

ResolveVisitor caught error in line 7, char 13: ...

The problem is that those exceptions are thrown inside the Scope class, which does not have any node objects associated, thus there is no node to pass to the exception object.

Any suggestions are appreciated.

[lukasoyen]

That is indeed a problem. Please refer to the rejected #1.

[cpfr]

I'm not sure if I understand the discussion correctly. You suggested that
"proper error messages via populated exceptions is a good reason to pass them in."

You mean passing an ASTNode to the resolve methods? How is this different from what lpradel did?

[lukasoyen]

That is what happend with this commit https://github.com/lpradel/moco/commit/e3b4bb03846bbafb0dd97b2e374f2bb660254e8b. I can't remember why it wasn't merged.