2010YOUY01 opened a new pull request, #8258: URL: https://github.com/apache/arrow-datafusion/pull/8258
## Which issue does this PR close? <!-- We generally require a GitHub issue to be filed for all bug fixes and enhancements and this helps us generate change logs for our releases. You can link an issue to this PR using the GitHub syntax. For example `Closes #123` indicates that this PR will close issue #123. --> Part of https://github.com/apache/arrow-datafusion/issues/8157 ## Rationale for this change <!-- Why are you proposing this change? If this is already explained clearly in the issue then this section is not needed. Explaining clearly why changes are proposed helps reviewers understand your changes and offer better suggestions for fixes. --> See #8157 for the rationale: Creation of `Expr`s for `BuiltinScalarFunctions` can be done statelessly ```rust let expr1 = abs(lit(-1)); let expr2 = call_fn("abs", vec![lit(-1)]); ``` However, we can't do that for ScalarUDFs because they are registered within `SessionState`, it's only possible to do ```rust let ctx = create_context()?; ctx.register_udf(abs_impl); let expr2 = ctx.call_fn("abs", vec![lit(-1)]); ``` For the ongoing plan to migrate functions from `BuiltinScalarFunction` to `ScalarUDF` based implementation (ref #8045 ), we would like the `ScalarUDF` based functions to continue to support the original `Expr` construction API, so the `Expr` struct should have a variant for unresolved name, and then we can add a `AnalyzerRule` to resolve the function. This PR only include refactor preparation for UDF `Expr` support. ## What changes are included in this PR? <!-- There is no need to duplicate the description in the issue here but it is sometimes worth providing a summary of the individual changes in this PR. --> 1. Change `Expr::ScalarFunction` ```rust // before pub struct ScalarFunction { /// The function pub fun: built_in_function::BuiltinScalarFunction, /// List of expressions to feed to the functions as arguments pub args: Vec<Expr>, } // This PR #[derive(Debug, Clone, PartialEq, Eq, Hash)] pub enum ScalarFunctionDefinition { /// Resolved to a `BuiltinScalarFunction` /// There is plan to migrate `BuiltinScalarFunction` to UDF-based implementation (issue#8045) /// This variant is planned to be removed in long term BuiltIn(built_in_function::BuiltinScalarFunction), /// Resolved to a user defined function UDF(Arc<crate::ScalarUDF>), /// A scalar function constructed with name, could be resolved with registered functions during /// analyzing. Name(Arc<str>), } /// ScalarFunction expression invokes a built-in scalar function #[derive(Clone, PartialEq, Eq, Hash, Debug)] pub struct ScalarFunction { /// The function pub func_def: ScalarFunctionDefinition, /// List of expressions to feed to the functions as arguments pub args: Vec<Expr>, } ``` 2. Remove `Expr::ScalarUDF` This way we can support unresolved function name variant. Also, merge the execution path for `BuiltinScalarFunction`/`ScalarUDF`, to make future work towards #8045 a bit easier ## Are these changes tested? Covered by existing tests. <!-- We typically require tests for all PRs in order to: 1. Prevent the code from being accidentally broken by subsequent changes 4. Serve as another way to document the expected behavior of the code If tests are not included in your PR, please explain why (for example, are they covered by existing tests)? --> ## Are there any user-facing changes? Yes, see comments for API changes <!-- If there are user-facing changes then we may require documentation to be updated before approving the PR. --> <!-- If there are any breaking changes to public APIs, please add the `api change` label. --> -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
