[antlr-interest] Passing user defined exceptions through the parser.

[Peter C. Chapin]

Sam Harwell wrote:

> Here's what I do. This is with the C# target so there are probably a few
> differences, but you'll get the idea.
>
> try
> {
>     MyLexer lexer = new MyLexer( new ANTLRStringStream( text ) );
>     CommonTokenStream tokens = new CommonTokenStream( lexer );
>     MyParser parser = new MyParser( tokens );
>     parser.program();
> }
> catch ( OperationCanceledException )
> {
>     // ...
> }
>   

I'm thinking that this works in C# because C# does not have statically
enforced exception specifications (I could be wrong... I know very
little about C#). In Java an attempt to throw OperationCanceledException
from a method invoked inside a rule will cause the parser to fail to
compile because the parser methods don't declare that exception in their
exception specifications.

Peter