Method str

crates/vm/src/protocol/object.rs:387–411

(&self, vm: &VirtualMachine)

        self.str(vm)?.try_into_utf8(vm)
    }
    pub fn str(&self, vm: &VirtualMachine) -> PyResult<PyRef<PyStr>> {
        let obj = match self.to_owned().downcast_exact::<PyStr>(vm) {
            Ok(s) => return Ok(s.into_pyref()),
            Err(obj) => obj,
        };
        // Fast path for exact int: skip __str__ method resolution
        let obj = match obj.downcast_exact::<PyInt>(vm) {
            Ok(int) => {
                return Ok(vm.ctx.new_str(int.to_str_radix_10()));
            }
            Err(obj) => obj,
        };
        // TODO: replace to obj.class().slots.str
        let str_method = match vm.get_special_method(&obj, identifier!(vm, __str__))? {
            Some(str_method) => str_method,
            None => return obj.repr(vm),
        };
        let s = str_method.invoke((), vm)?;
        s.downcast::<PyStr>().map_err(|obj| {
            vm.new_type_error(format!(
                "__str__ returned non-string (type {})",
                obj.class().name()
            ))
        })
    }

    // Equivalent to CPython's check_class. Returns Ok(()) if cls is a valid class,
    // Err with TypeError if not. Uses abstract_get_bases internally.