Method instantiate_value

crates/vm/src/exceptions.rs:447–473

(
        self,
        value: PyObjectRef,
        vm: &VirtualMachine,
    )

    }

    pub fn instantiate_value(
        self,
        value: PyObjectRef,
        vm: &VirtualMachine,
    ) -> PyResult<PyBaseExceptionRef> {
        let exc_inst = value.clone().downcast::<PyBaseException>().ok();
        match (self, exc_inst) {
            // both are instances; which would we choose?
            (Self::Instance(_exc_a), Some(_exc_b)) => {
                Err(vm.new_type_error("instance exception may not have a separate value"))
            }
            // if the "type" is an instance and the value isn't, use the "type"
            (Self::Instance(exc), None) => Ok(exc),
            // if the value is an instance of the type, use the instance value
            (Self::Class(cls), Some(exc)) if exc.fast_isinstance(&cls) => Ok(exc),
            // otherwise; construct an exception of the type using the value as args
            (Self::Class(cls), _) => {
                let args = match_class!(match value {
                    PyNone => vec![],
                    tup @ PyTuple => tup.to_vec(),
                    exc @ PyBaseException => exc.args().to_vec(),
                    obj => vec![obj],
                });
                vm.invoke_exception(cls, args)
            }
        }
    }
}

#[derive(Debug)]