Method lookup_special

crates/vm/src/protocol/object.rs:793–808

Equivalent to CPython's _PyObject_LookupSpecial Looks up a special method in the type's MRO without checking instance dict. Returns None if not found (masking AttributeError like CPython).

(&self, attr: &Py<PyStr>, vm: &VirtualMachine)

    /// Looks up a special method in the type's MRO without checking instance dict.
    /// Returns None if not found (masking AttributeError like CPython).
    pub fn lookup_special(&self, attr: &Py<PyStr>, vm: &VirtualMachine) -> Option<PyObjectRef> {
        let obj_cls = self.class();

        // Use PyType::lookup_ref (equivalent to CPython's _PyType_LookupRef)
        let res = obj_cls.lookup_ref(attr, vm)?;

        // If it's a descriptor, call its __get__ method
        let descr_get = res.class().slots.descr_get.load();
        if let Some(descr_get) = descr_get {
            let obj_cls = obj_cls.to_owned().into();
            // CPython ignores exceptions in _PyObject_LookupSpecial and returns NULL
            descr_get(res, Some(self.to_owned()), Some(obj_cls), vm).ok()
        } else {
            Some(res)
        }
    }
}