alamb commented on issue #8624: URL: https://github.com/apache/arrow-datafusion/issues/8624#issuecomment-1908178559
Thanks @yyy1000 -- FYI aware this is likely to be an exercise in careful API design Perhaps you could look into extending `ScalarFunctionImpl` https://github.com/apache/arrow-datafusion/blob/bc0ba6a724aaaf312b770451718cbce696de6640/datafusion/expr/src/udf.rs#L237 in backwards compatible way For example: ```rust trait ScalarUDFImpl { ... /// What [`DataType`] will be returned by this function, given the types of /// the expr arguments fn return_type_from_exprs(&self, arg_exprs: &[Expr], schema: &SchemaRef) -> Result<DataType> { // provide default implementation that calls `self.return_type()` // so that people don't have to implement `return_type_from_exprs` if they dont want to } ... } ``` An exellent test of the new API would be to see if you can implement `arrow_cast` as a `ScalarUDF` we can put it into `datafusion-functions` after https://github.com/apache/arrow-datafusion/pull/8705 is merged -- 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]
