Jimexist commented on a change in pull request #303:
URL: https://github.com/apache/arrow-datafusion/pull/303#discussion_r630623061



##########
File path: datafusion/src/physical_plan/functions.rs
##########
@@ -1373,20 +1370,26 @@ impl PhysicalExpr for ScalarFunctionExpr {
     }
 
     fn evaluate(&self, batch: &RecordBatch) -> Result<ColumnarValue> {
-        // evaluate the arguments
-        let inputs = self
-            .args
-            .iter()
-            .map(|e| e.evaluate(batch))
-            .collect::<Result<Vec<_>>>()?;
+        // evaluate the arguments, if there are no arguments we'll instead 
pass in a null array of
+        // batch size (as a convention)
+        let inputs = match self.args.len() {
+            0 => vec![ColumnarValue::Array(Arc::new(NullArray::new(

Review comment:
       @alamb @Dandandan and @jorgecarleitao thanks for the discussion.
   
   I agree that both ways are similar and equally “hacky” but for lack of a 
better solution they are okay. I'd slightly prefer null array because there's 
no ScalarValue::USize and having to convert from/to UInt32 is a bit cumbersome.




-- 
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]


Reply via email to