address comment

arrow/src/array/array_decimal.rs

@@ -332,28 +332,20 @@ impl Decimal256Array {
     // Validates decimal values in this array can be properly interpreted
     // with the specified precision.
     fn validate_decimal_precision(&self, precision: usize) -> Result<()> {
-        let current_end = self.data.len();
-        let mut current: usize = 0;
-        let data = &self.data;
-
-        while current != current_end {
-            if self.is_null(current) {
-                current += 1;
-                continue;
-            } else {
-                let offset = current + data.offset();
-                current += 1;
+        (0..self.len()).try_for_each(|idx| {
+            if self.is_valid(idx) {
                 let raw_val = unsafe {
-                    let pos = self.value_offset_at(offset);
+                    let pos = self.value_offset(idx);
                     std::slice::from_raw_parts(
                         self.raw_value_data_ptr().offset(pos as isize),
                         Self::VALUE_LENGTH as usize,
                     )
                 };
-                validate_decimal256_precision_with_lt_bytes(raw_val, precision)?;
+                validate_decimal256_precision_with_lt_bytes(raw_val, precision)
+            } else {
+                Ok(())
             }
-        }
-        Ok(())
+        })
     }
 
     /// Returns a Decimal array with the same data as self, with the