improve error handling

1 files changed, 51 insertions, 0 deletions

diff --git a/nihil.ucl/errc.cc b/nihil.ucl/errc.cc
new file mode 100644
index 0000000..fc1d9f8
--- /dev/null
+++ b/nihil.ucl/errc.cc
@@ -0,0 +1,51 @@
+/*
+ * This source code is released into the public domain.
+ */
+
+module;
+
+#include <string>
+#include <system_error>
+
+module nihil.ucl;
+
+import nihil;
+
+namespace nihil::ucl {
+
+struct ucl_error_category final : std::error_category {
+	auto name() const noexcept -> char const * override;
+	auto message(int err) const -> std::string override;
+};
+
+auto ucl_category() noexcept -> std::error_category &
+{
+	static auto category = ucl_error_category();
+	return category;
+}
+
+auto make_error_condition(errc ec) -> std::error_condition
+{
+	return {static_cast<int>(ec), ucl_category()};
+}
+
+auto ucl_error_category::name() const noexcept -> char const *
+{
+	return "nihil.ucl";
+}
+
+auto ucl_error_category::message(int err) const -> std::string
+{
+	switch (static_cast<errc>(err)) {
+	case errc::no_error:
+		return "No error";
+	case errc::failed_to_create_object:
+		return "Failed to create UCL object";
+	case errc::type_mismatch:
+		return "UCL type does not match expected type";
+	default:
+		return "Undefined error";
+	}
+}
+
+} // namespace nihil::ucl