Apply suggestion of using a regular method

Author: pitrou

cpp/src/arrow/compute/kernels/vector_sort.cc

@@ -114,8 +114,7 @@ class ChunkedArraySorter : public TypeVisitor {
 
       std::vector<ChunkedNullPartitionResult> chunk_sorted(num_chunks);
       for (int i = 0; i < num_chunks; ++i) {
-        chunk_sorted[i] = ChunkedNullPartitionResult::TranslateFrom(
-            sorted[i], indices_begin_, chunked_indices_begin);
+        chunk_sorted[i] = sorted[i].TranslateTo(indices_begin_, chunked_indices_begin);
       }
 
       auto merge_nulls = [&](CompressedChunkLocation* nulls_begin,
@@ -158,8 +157,7 @@ class ChunkedArraySorter : public TypeVisitor {
 
       // Reverse everything
       sorted.resize(1);
-      sorted[0] = NullPartitionResult::TranslateFrom(
-          chunk_sorted[0], chunked_indices_begin, indices_begin_);
+      sorted[0] = chunk_sorted[0].TranslateTo(chunked_indices_begin, indices_begin_);
 
       RETURN_NOT_OK(chunked_mapper.PhysicalToLogical());
     }
@@ -706,8 +704,7 @@ class TableSorter {
 
       std::vector<ChunkedNullPartitionResult> chunk_sorted(num_batches);
       for (int64_t i = 0; i < num_batches; ++i) {
-        chunk_sorted[i] = ChunkedNullPartitionResult::TranslateFrom(
-            sorted[i], indices_begin_, chunked_indices_begin);
+        chunk_sorted[i] = sorted[i].TranslateTo(indices_begin_, chunked_indices_begin);
       }
 
       struct Visitor {

cpp/src/arrow/compute/kernels/vector_sort_internal.h

@@ -195,15 +195,14 @@ struct GenericNullPartitionResult {
     return {midpoint, indices_end, indices_begin, midpoint};
   }
 
-  template <typename SourceIndexType>
-  static GenericNullPartitionResult TranslateFrom(
-      GenericNullPartitionResult<SourceIndexType> source,
-      SourceIndexType* source_indices_begin, IndexType* target_indices_begin) {
+  template <typename TargetIndexType>
+  GenericNullPartitionResult<TargetIndexType> TranslateTo(
+      IndexType* indices_begin, TargetIndexType* target_indices_begin) const {
     return {
-        (source.non_nulls_begin - source_indices_begin) + target_indices_begin,
-        (source.non_nulls_end - source_indices_begin) + target_indices_begin,
-        (source.nulls_begin - source_indices_begin) + target_indices_begin,
-        (source.nulls_end - source_indices_begin) + target_indices_begin,
+        (non_nulls_begin - indices_begin) + target_indices_begin,
+        (non_nulls_end - indices_begin) + target_indices_begin,
+        (nulls_begin - indices_begin) + target_indices_begin,
+        (nulls_end - indices_begin) + target_indices_begin,
     };
   }
 };