Is it possible to continue parsing with other rules after an exception is raised in semantics?

Question

Is it possible to fallback to other rules after an exception is raised in a semantic action? Like the following (contrived) scenario:

var = /[a-zA-Z]+/;
keyword = 'for' | 'in';
a = var:var | keyword:keyword;

def a(ast):
    if (ast.var not in symbolTable):
        raise Exception()

and when the exception is raised, parsing continues with the 'keyword' rule. I am aware of the @@keyword feature, but I want to declare keywords at runtime (my parser is for a programming language with user-defined operators).

Answer 1

如果语义代码引发tatsu.exceptions.FailedSemantics ，则异常将被视为ParseException ，因此将恢复正常的解析控制流。