address comment

Signed-off-by: jayzhan211 <[email protected]>

datafusion/core/tests/sqllogictests/test_files/array.slt

@@ -365,26 +365,25 @@ select array_concat(make_array(), make_array(2, 3));
 ----
 [2, 3]
 
-# array_concat with different dimensions
-# 2D + 1D
+# array_concat with different dimensions #1 (2D + 1D)
 query ?
 select array_concat(make_array([1,2], [3,4]), make_array(5, 6))
 ----
 [[1, 2], [3, 4], [5, 6]]
 
-# 1D + 2D
+# array_concat with different dimensions #2 (1D + 2D)
 query ?
 select array_concat(make_array(5, 6), make_array([1,2], [3,4]))
 ----
 [[5, 6], [1, 2], [3, 4]]
 
-# 2D + 1D + 1D
+# array_concat with different dimensions #3 (2D + 1D + 1D)
 query ?
 select array_concat(make_array([1,2], [3,4]), make_array(5, 6), make_array(7,8))
 ----
 [[1, 2], [3, 4], [5, 6], [7, 8]]
 
-# 1D + 2D + 3D
+# array_concat with different dimensions #4 (1D + 2D + 3D)
 query ?
 select array_concat(make_array(10, 20), make_array([30, 40]), make_array([[50, 60]]))
 ----

datafusion/physical-expr/src/array_expressions.rs

@@ -400,15 +400,14 @@ fn compute_array_ndims(arg: u8, arr: ArrayRef) -> Result<u8> {
 }
 
 fn align_array_dimensions(args: Vec<ArrayRef>) -> Result<Vec<ArrayRef>> {
-    // Compute the number of dimensions for each array
-    let args_ndim: Result<Vec<u8>> = args
+    // Find the maximum number of dimensions
+    let max_ndim: u8 = *args
         .iter()
         .map(|arr| compute_array_ndims(0, arr.clone()))
-        .collect();
-    let args_ndim = args_ndim?;
-
-    // Find the maximum number of dimensions
-    let max_ndim = *args_ndim.iter().max().unwrap();
+        .collect::<Result<Vec<u8>>>()?
+        .iter()
+        .max()
+        .unwrap();
 
     // Align the dimensions of the arrays
     let aligned_args: Result<Vec<ArrayRef>> = args