I'm nowhere near confident that I've handled all the error cases, and I imagine there are still ugly Python exceptions that can bubble up to the top. We could make the grammar more explicit, like a data structure, rather than using recursive descent. And then use that grammar data structure to generate random inputs. The inputs should either evaluate okay or they should return an error of the expected type. No unexpected Python errors.
I'm nowhere near confident that I've handled all the error cases, and I imagine there are still ugly Python exceptions that can bubble up to the top. We could make the grammar more explicit, like a data structure, rather than using recursive descent. And then use that grammar data structure to generate random inputs. The inputs should either evaluate okay or they should return an error of the expected type. No unexpected Python errors.