[GitHub] [arrow] andygrove commented on a change in pull request #7812: ARROW-9507: [Rust] [DataFusion] Implement Display for PhysicalExpr

[GitBox <gi...@apache.org>]

andygrove commented on a change in pull request #7812:
URL: https://github.com/apache/arrow/pull/7812#discussion_r457676182



##########
File path: rust/datafusion/src/execution/physical_plan/udf.rs
##########
@@ -84,6 +86,19 @@ impl ScalarFunctionExpr {
     }
 }
 
+impl fmt::Display for ScalarFunctionExpr {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}(", self.name)?;
+        for i in 0..self.args.len() {

Review comment:
       That wouldn't work but I pushed this change instead:
   
   ```rust
           write!(
               f,
               "{}({})",
               self.name,
               self.args
                   .iter()
                   .map(|e| format!("{}", e))
                   .collect::<Vec<String>>()
                   .join(", ")
           )
   ```




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