ListViewArray: Implement Compare + (TODO: tests)

cpp/src/arrow/compare.cc

@@ -403,7 +403,40 @@ class RangeDataEqualsImpl {
   }
 
   Status Visit(const ListViewType& type) {
-    return Status::NotImplemented("comparing ListViewType");
+    // Sizes are required to be identical for full equality, so we test them first
+    const auto* left_sizes = left_.GetValues<int32_t>(2);
+    const auto* right_sizes = right_.GetValues<int32_t>(2);
+    auto compare_sizes = [&](int64_t i, int64_t length) -> bool {
+      return memcmp(left_sizes + left_start_idx_ + i, right_sizes + right_start_idx_ + i,
+                    length * sizeof(int32_t)) == 0;
+    };
+    VisitValidRuns(std::move(compare_sizes));
+    if (!result_) {
+      return Status::OK();
+    }
+
+    // All sizes match, now compare the valid list views
+    const auto* left_offsets = left_.GetValues<int32_t>(1);
+    const auto* right_offsets = right_.GetValues<int32_t>(1);
+    const ArrayData& left_values = *left_.child_data[0];
+    const ArrayData& right_values = *right_.child_data[0];
+    auto compare_view = [&](int64_t i, int64_t length) -> bool {
+      for (int64_t j = i; j < i + length; ++j) {
+        const int32_t left_offset = left_offsets[left_start_idx_ + j];
+        const int32_t right_offset = right_offsets[right_start_idx_ + j];
+        const int32_t size = left_sizes[left_start_idx_ + j];
+        RangeDataEqualsImpl impl(options_, floating_approximate_, left_values,
+                                 right_values,
+                                 left_start_idx_ + left_.offset + left_offset,
+                                 right_start_idx_ + right_.offset + right_offset, size);
+        if (!impl.Compare()) {
+          return false;
+        }
+      }
+      return true;
+    };
+    VisitValidRuns(compare_view);
+    return Status::OK();
   }
 
   Status Visit(const ExtensionType& type) {