tqchen opened a new pull request #5314: [IR] Allow non-nullable ObjectRef, introduce Optional<T>. URL: https://github.com/apache/incubator-tvm/pull/5314 We use ObjectRef and their sub-classes extensively throughout our codebase. Each of ObjectRef's sub-classes are nullable, which means they can hold nullptr as their values. While in some places we need nullptr as an alternative value. The implicit support for nullptr in all ObjectRef creates additional burdens for the developer to explicitly check defined in many places of the codebase. Moreover, it is unclear from the API's intentional point of view whether we want a nullable object or not-null version(many cases we want the later). Borrowing existing wisdoms from languages like Rust. We propose to introduce non-nullable ObjectRef, and Optional<T> container that represents a nullable variant. To keep backward compatiblity, we will start by allowing most ObjectRef to be nullable. However, we should start to use Optional<T> as the type in places where we know nullable is a requirement. Gradually, we will move most of the ObjectRef to be non-nullable and use Optional<T> in the nullable cases. Such explicitness in typing can help reduce the potential problems in our codebase overall. Changes in this PR: - Introduce _type_is_nullable attribute to ObjectRef - Introduce Optional<T> - Change String to be non-nullable. - Change the API of function->GetAttr to return Optional<T> Thanks for contributing to TVM! Please refer to guideline https://tvm.apache.org/docs/contribute/ for useful information and tips. After the pull request is submitted, please request code reviews from [Reviewers](https://github.com/apache/incubator-tvm/blob/master/CONTRIBUTORS.md#reviewers) by @ them in the pull request thread.
---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
