Minor fix

Signed-off-by: Chojan Shang <[email protected]>

Author: PsiACE

datafusion/functions/src/string/levenshtein.rs

@@ -22,7 +22,7 @@ use arrow::array::{ArrayRef, Int32Array, Int64Array, OffsetSizeTrait};
 use arrow::datatypes::DataType;
 
 use crate::utils::{make_scalar_function, utf8_to_int_type};
-use datafusion_common::cast::as_generic_string_array;
+use datafusion_common::cast::{as_generic_string_array, as_string_view_array};
 use datafusion_common::utils::datafusion_strsim;
 use datafusion_common::{exec_err, Result};
 use datafusion_expr::ColumnarValue;
@@ -74,7 +74,9 @@ impl ScalarUDFImpl for LevenshteinFunc {
 
     fn invoke(&self, args: &[ColumnarValue]) -> Result<ColumnarValue> {
         match args[0].data_type() {
-            DataType::Utf8View | DataType::Utf8 => make_scalar_function(levenshtein::<i32>, vec![])(args),
+            DataType::Utf8View | DataType::Utf8 => {
+                make_scalar_function(levenshtein::<i32>, vec![])(args)
+            }
             DataType::LargeUtf8 => make_scalar_function(levenshtein::<i64>, vec![])(args),
             other => {
                 exec_err!("Unsupported data type {other:?} for function levenshtein")
@@ -92,10 +94,26 @@ pub fn levenshtein<T: OffsetSizeTrait>(args: &[ArrayRef]) -> Result<ArrayRef> {
             args.len()
         );
     }
-    let str1_array = as_generic_string_array::<T>(&args[0])?;
-    let str2_array = as_generic_string_array::<T>(&args[1])?;
+
     match args[0].data_type() {
-        DataType::Utf8View | DataType::Utf8 => {
+        DataType::Utf8View => {
+            let str1_array = as_string_view_array(&args[0])?;
+            let str2_array = as_string_view_array(&args[1])?;
+            let result = str1_array
+                .iter()
+                .zip(str2_array.iter())
+                .map(|(string1, string2)| match (string1, string2) {
+                    (Some(string1), Some(string2)) => {
+                        Some(datafusion_strsim::levenshtein(string1, string2) as i32)
+                    }
+                    _ => None,
+                })
+                .collect::<Int32Array>();
+            Ok(Arc::new(result) as ArrayRef)
+        }
+        DataType::Utf8 => {
+            let str1_array = as_generic_string_array::<T>(&args[0])?;
+            let str2_array = as_generic_string_array::<T>(&args[1])?;
             let result = str1_array
                 .iter()
                 .zip(str2_array.iter())
@@ -109,6 +127,8 @@ pub fn levenshtein<T: OffsetSizeTrait>(args: &[ArrayRef]) -> Result<ArrayRef> {
             Ok(Arc::new(result) as ArrayRef)
         }
         DataType::LargeUtf8 => {
+            let str1_array = as_generic_string_array::<T>(&args[0])?;
+            let str2_array = as_generic_string_array::<T>(&args[1])?;
             let result = str1_array
                 .iter()
                 .zip(str2_array.iter())