clean up code

Author: alamb

datafusion/expr-common/src/type_coercion/binary.rs

@@ -29,9 +29,7 @@ use arrow::datatypes::{
     DECIMAL128_MAX_SCALE, DECIMAL256_MAX_PRECISION, DECIMAL256_MAX_SCALE,
 };
 use datafusion_common::types::NativeType;
-use datafusion_common::{
-    exec_datafusion_err, exec_err, internal_err, plan_datafusion_err, plan_err, Result,
-};
+use datafusion_common::{exec_err, internal_err, plan_datafusion_err, plan_err, Result};
 use itertools::Itertools;
 
 /// The type signature of an instantiation of binary operator expression such as
@@ -869,54 +867,6 @@ fn get_wider_decimal_type(
     }
 }
 
-/// Returns the wider type among arguments `lhs` and `rhs`.
-/// The wider type is the type that can safely represent values from both types
-/// without information loss. Returns an Error if types are incompatible.
-pub fn get_wider_type(lhs: &DataType, rhs: &DataType) -> Result<DataType> {
-    use arrow::datatypes::DataType::*;
-    Ok(match (lhs, rhs) {
-        (lhs, rhs) if lhs == rhs => lhs.clone(),
-        // Right UInt is larger than left UInt.
-        (UInt8, UInt16 | UInt32 | UInt64) | (UInt16, UInt32 | UInt64) | (UInt32, UInt64) |
-        // Right Int is larger than left Int.
-        (Int8, Int16 | Int32 | Int64) | (Int16, Int32 | Int64) | (Int32, Int64) |
-        // Right Float is larger than left Float.
-        (Float16, Float32 | Float64) | (Float32, Float64) |
-        // Right String is larger than left String.
-        (Utf8, LargeUtf8) |
-        // Any right type is wider than a left hand side Null.
-        (Null, _) => rhs.clone(),
-        // Left UInt is larger than right UInt.
-        (UInt16 | UInt32 | UInt64, UInt8) | (UInt32 | UInt64, UInt16) | (UInt64, UInt32) |
-        // Left Int is larger than right Int.
-        (Int16 | Int32 | Int64, Int8) | (Int32 | Int64, Int16) | (Int64, Int32) |
-        // Left Float is larger than right Float.
-        (Float32 | Float64, Float16) | (Float64, Float32) |
-        // Left String is larger than right String.
-        (LargeUtf8, Utf8) |
-        // Any left type is wider than a right hand side Null.
-        (_, Null) => lhs.clone(),
-        (List(lhs_field), List(rhs_field)) => {
-            let field_type =
-                get_wider_type(lhs_field.data_type(), rhs_field.data_type())?;
-            if lhs_field.name() != rhs_field.name() {
-                return Err(exec_datafusion_err!(
-                    "There is no wider type that can represent both {lhs} and {rhs}."
-                ));
-            }
-            assert_eq!(lhs_field.name(), rhs_field.name());
-            let field_name = lhs_field.name();
-            let nullable = lhs_field.is_nullable() | rhs_field.is_nullable();
-            List(Arc::new(Field::new(field_name, field_type, nullable)))
-        }
-        (_, _) => {
-            return Err(exec_datafusion_err!(
-                "There is no wider type that can represent both {lhs} and {rhs}."
-            ));
-        }
-    })
-}
-
 /// Convert the numeric data type to the decimal data type.
 /// We support signed and unsigned integer types and floating-point type.
 fn coerce_numeric_type_to_decimal(numeric_type: &DataType) -> Option<DataType> {

datafusion/functions-nested/src/concat.rs

@@ -29,7 +29,7 @@ use datafusion_common::{
     cast::as_generic_list_array, exec_err, not_impl_err, plan_err, utils::list_ndims,
 };
 use datafusion_expr::{
-    type_coercion::binary::get_wider_type, ColumnarValue, Documentation, ScalarUDFImpl,
+    ColumnarValue, Documentation, ScalarUDFImpl,
     Signature, Volatility,
 };
 use datafusion_macros::user_doc;
@@ -276,25 +276,32 @@ impl ScalarUDFImpl for ArrayConcat {
         let mut expr_type = DataType::Null;
         let mut max_dims = 0;
         for arg_type in arg_types {
-            match arg_type {
-                DataType::List(field) => {
-                    if !field.data_type().equals_datatype(&DataType::Null) {
-                        let dims = list_ndims(arg_type);
-                        expr_type = match max_dims.cmp(&dims) {
-                            Ordering::Greater => expr_type,
-                            Ordering::Equal => get_wider_type(&expr_type, arg_type)?,
-                            Ordering::Less => {
-                                max_dims = dims;
-                                arg_type.clone()
-                            }
-                        };
+            let DataType::List(field) = arg_type else {
+                return plan_err!(
+                    "The array_concat function can only accept list as the args."
+                );
+            };
+            if !field.data_type().equals_datatype(&DataType::Null) {
+                let dims = list_ndims(arg_type);
+                expr_type = match max_dims.cmp(&dims) {
+                    Ordering::Greater => expr_type,
+                    Ordering::Equal => {
+                        if expr_type == DataType::Null {
+                            arg_type.clone()
+                        } else if !expr_type.equals_datatype(arg_type) {
+                            return plan_err!(
+                            "It is not possible to concatenate arrays of different types. Expected: {}, got: {}", expr_type, arg_type
+                                );
+                        } else {
+                            expr_type
+                        }
                     }
-                }
-                _ => {
-                    return plan_err!(
-                        "The array_concat function can only accept list as the args."
-                    )
-                }
+
+                    Ordering::Less => {
+                        max_dims = dims;
+                        arg_type.clone()
+                    }
+                };
             }
         }
 

datafusion/sqllogictest/test_files/array.slt

@@ -2876,14 +2876,14 @@ select array_concat(
 [1, 2, 3]
 
 # Concatenating Mixed types (doesn't work)
-query error DataFusion error: Arrow error: Invalid argument error: It is not possible to concatenate arrays of different data types\.
+query error DataFusion error: Error during planning: It is not possible to concatenate arrays of different types\. Expected: List\(Field \{ name: "item", data_type: Utf8, nullable: true, dict_id: 0, dict_is_ordered: false, metadata: \{\} \}\), got: List\(Field \{ name: "item", data_type: LargeUtf8, nullable: true, dict_id: 0, dict_is_ordered: false, metadata: \{\} \}\)
 select array_concat(
   [arrow_cast('1', 'Utf8'), arrow_cast('2', 'Utf8')],
   [arrow_cast('3', 'LargeUtf8')]
 );
 
 # Concatenating Mixed types (doesn't work)
-query error DataFusion error: Execution error: There is no wider type that can represent both Utf8 and Utf8View\.
+query error DataFusion error: Error during planning: It is not possible to concatenate arrays of different types\. Expected: List\(Field \{ name: "item", data_type: Utf8, nullable: true, dict_id: 0, dict_is_ordered: false, metadata: \{\} \}\), got: List\(Field \{ name: "item", data_type: Utf8View, nullable: true, dict_id: 0, dict_is_ordered: false, metadata: \{\} \}\)
 select array_concat(
   [arrow_cast('1', 'Utf8'), arrow_cast('2', 'Utf8')],
   [arrow_cast('3', 'Utf8View')]