refactor: simplify cast_string_to_interval (#5195)

arrow-cast/src/cast.rs

@@ -2444,103 +2444,76 @@ fn cast_string_to_timestamp_impl<O: OffsetSizeTrait, T: ArrowTimestampType, Tz:
     }
 }
 
-fn cast_string_to_year_month_interval<Offset: OffsetSizeTrait>(
+fn cast_string_to_interval<Offset, F, ArrowType>(
     array: &dyn Array,
     cast_options: &CastOptions,
-) -> Result<ArrayRef, ArrowError> {
+    parse_function: F,
+) -> Result<ArrayRef, ArrowError>
+where
+    Offset: OffsetSizeTrait,
+    ArrowType: ArrowPrimitiveType,
+    F: Fn(&str) -> Result<ArrowType::Native, ArrowError> + Copy,
+{
     let string_array = array
         .as_any()
         .downcast_ref::<GenericStringArray<Offset>>()
         .unwrap();
     let interval_array = if cast_options.safe {
         let iter = string_array
             .iter()
-            .map(|v| v.and_then(|v| parse_interval_year_month(v).ok()));
+            .map(|v| v.and_then(|v| parse_function(v).ok()));
 
         // Benefit:
         //     20% performance improvement
         // Soundness:
         //     The iterator is trustedLen because it comes from an `StringArray`.
-        unsafe { IntervalYearMonthArray::from_trusted_len_iter(iter) }
+        unsafe { PrimitiveArray::<ArrowType>::from_trusted_len_iter(iter) }
     } else {
         let vec = string_array
             .iter()
-            .map(|v| v.map(parse_interval_year_month).transpose())
+            .map(|v| v.map(parse_function).transpose())
             .collect::<Result<Vec<_>, ArrowError>>()?;
 
         // Benefit:
         //     20% performance improvement
         // Soundness:
         //     The iterator is trustedLen because it comes from an `StringArray`.
-        unsafe { IntervalYearMonthArray::from_trusted_len_iter(vec) }
+        unsafe { PrimitiveArray::<ArrowType>::from_trusted_len_iter(vec) }
     };
     Ok(Arc::new(interval_array) as ArrayRef)
 }
 
-fn cast_string_to_day_time_interval<Offset: OffsetSizeTrait>(
+fn cast_string_to_year_month_interval<Offset: OffsetSizeTrait>(
     array: &dyn Array,
     cast_options: &CastOptions,
 ) -> Result<ArrayRef, ArrowError> {
-    let string_array = array
-        .as_any()
-        .downcast_ref::<GenericStringArray<Offset>>()
-        .unwrap();
-    let interval_array = if cast_options.safe {
-        let iter = string_array
-            .iter()
-            .map(|v| v.and_then(|v| parse_interval_day_time(v).ok()));
-
-        // Benefit:
-        //     20% performance improvement
-        // Soundness:
-        //     The iterator is trustedLen because it comes from an `StringArray`.
-        unsafe { IntervalDayTimeArray::from_trusted_len_iter(iter) }
-    } else {
-        let vec = string_array
-            .iter()
-            .map(|v| v.map(parse_interval_day_time).transpose())
-            .collect::<Result<Vec<_>, ArrowError>>()?;
+    cast_string_to_interval::<Offset, _, IntervalYearMonthType>(
+        array,
+        cast_options,
+        parse_interval_year_month,
+    )
+}
 
-        // Benefit:
-        //     20% performance improvement
-        // Soundness:
-        //     The iterator is trustedLen because it comes from an `StringArray`.
-        unsafe { IntervalDayTimeArray::from_trusted_len_iter(vec) }
-    };
-    Ok(Arc::new(interval_array) as ArrayRef)
+fn cast_string_to_day_time_interval<Offset: OffsetSizeTrait>(
+    array: &dyn Array,
+    cast_options: &CastOptions,
+) -> Result<ArrayRef, ArrowError> {
+    cast_string_to_interval::<Offset, _, IntervalDayTimeType>(
+        array,
+        cast_options,
+        parse_interval_day_time,
+    )
 }
 
 fn cast_string_to_month_day_nano_interval<Offset: OffsetSizeTrait>(
     array: &dyn Array,
     cast_options: &CastOptions,
 ) -> Result<ArrayRef, ArrowError> {
-    let string_array = array
-        .as_any()
-        .downcast_ref::<GenericStringArray<Offset>>()
-        .unwrap();
-    let interval_array = if cast_options.safe {
-        let iter = string_array
-            .iter()
-            .map(|v| v.and_then(|v| parse_interval_month_day_nano(v).ok()));
-
-        // Benefit:
-        //     20% performance improvement
-        // Soundness:
-        //     The iterator is trustedLen because it comes from an `StringArray`.
-        unsafe { IntervalMonthDayNanoArray::from_trusted_len_iter(iter) }
-    } else {
-        let vec = string_array
-            .iter()
-            .map(|v| v.map(parse_interval_month_day_nano).transpose())
-            .collect::<Result<Vec<_>, ArrowError>>()?;
-
-        // Benefit:
-        //     20% performance improvement
-        // Soundness:
-        //     The iterator is trustedLen because it comes from an `StringArray`.
-        unsafe { IntervalMonthDayNanoArray::from_trusted_len_iter(vec) }
-    };
-    Ok(Arc::new(interval_array) as ArrayRef)
+    cast_string_to_interval::<Offset, _, IntervalMonthDayNanoType>(
+        array,
+        cast_options,
+        parse_interval_month_day_nano,
+    )
 }
 
 fn adjust_timestamp_to_timezone<T: ArrowTimestampType>(