custom_aggregator comparator, sort by categories

Author: schaumb

src/dataframe/impl/data_source.cpp

@@ -552,7 +552,8 @@ data_source::final_info::final_info(const data_source &source) :
 		for (std::size_t d{}; d < dimensions; ++d) {
 			auto val = source.dimensions[d].values[r];
 			record +=
-			    source.dimension_names[d] + ':'
+			    source.dimension_names[d] + '['
+			    + std::to_string(static_cast<int32_t>(val)) + "]:"
 			    + (val == nav ? "null"
 			                  : source.dimensions[d].categories[val])
 			    + ";";

src/dataframe/impl/dataframe.cpp

@@ -159,8 +159,9 @@ void dataframe::set_sort(series_identifier series,
 	case dimension: {
 		std::optional<std::vector<std::uint32_t>> indices;
 		if (const auto &dim = unsafe_get<dimension>(ser).second;
-		    std::ranges::is_sorted(
-		        indices.emplace(dim.get_indices(sort)))
+		    ((sort_ptr && *sort_ptr == sort_type::by_categories)
+		        || std::ranges::is_sorted(
+		            indices.emplace(dim.get_indices(sort))))
 		    && (na_pos == dim.na_pos || !dim.contains_nav))
 			break;
 
@@ -180,12 +181,16 @@ void dataframe::set_sort(series_identifier series,
 			throw std::runtime_error(
 			    "Measure series cannot be sorted by categories.");
 		switch (*sort_ptr) {
+		default:
 		case sort_type::less:
 		case sort_type::greater: break;
 		case sort_type::natural_less:
 		case sort_type::natural_greater:
 			throw std::runtime_error(
 			    "Measure series cannot be sorted by natural order.");
+		case sort_type::by_categories:
+			throw std::runtime_error(
+			    "Measure series cannot be sorted by categories.");
 		}
 		break;
 	}

src/dataframe/interface.h

@@ -24,7 +24,13 @@ enum class aggregator_type {
 	exists
 };
 
-enum class sort_type { less, greater, natural_less, natural_greater };
+enum class sort_type {
+	less,
+	greater,
+	natural_less,
+	natural_greater,
+	by_categories
+};
 
 enum class na_position { last, first };
 
@@ -47,6 +53,21 @@ struct custom_aggregator
 	{
 		return std::visit<std::string_view>(std::identity{}, name);
 	}
+
+	auto operator<=>(const custom_aggregator &oth) const
+	{
+		return get_name() <=> oth.get_name();
+	}
+
+	auto operator!=(const custom_aggregator &oth) const
+	{
+		return get_name() != oth.get_name();
+	}
+
+	auto operator==(const custom_aggregator &oth) const
+	{
+		return get_name() == oth.get_name();
+	}
 };
 
 class dataframe_interface :