ucl, config: use monadic error handling more

1 files changed, 11 insertions, 24 deletions

diff --git a/nihil.config/read.cc b/nihil.config/read.cc
index 0a5fcad..e7def91 100644
--- a/nihil.config/read.cc
+++ b/nihil.config/read.cc
@@ -11,15 +11,15 @@ module;
 #include <iterator>
 #include <string>
 
+module nihil.config;
+
 import nihil;
 import nihil.ucl;
 
-module nihil.config;
-
 namespace nihil::config {
 
 auto read_from(std::filesystem::path const &filename)
-	-> std::expected<void, nihil::error>
+	-> std::expected<void, error>
 {
 	// TODO: nihil.ucl should have a way to load UCL from a filename.
 
@@ -29,33 +29,20 @@ auto read_from(std::filesystem::path const &filename)
 		// Ignore ENOENT, it simply means we haven't created the
 		// config file yet, so default values will be used.
 		if (err.error().root_cause() == std::errc::no_such_file_or_directory)
-			return {};
+			co_return {};
 		auto errstr = std::format("cannot read {}", filename.string());
-		return std::unexpected(nihil::error(errstr, err.error()));
+		co_return std::unexpected(error(errstr, err.error()));
 	}
 
 	// Parse the UCL.
-	try {
-		auto uclconfig = ucl::parse(config_text);
-
-		for (auto &&[key, value] : uclconfig) {
-			auto &opt = store::get().fetch(key);
-			opt.from_ucl(value);
-		}
-	} catch (unknown_option const &) {
-		// This is probably an old option which has been removed;
-		// ignore it, and we'll remove the bad option next time
-		// we write the config.
-	} catch (error const &err) {
-		// Include the filename in any other config errors.
-		throw error(std::format("{}: {}", filename.string(),
-					err.what()));
-	} catch (ucl::error const &err) {
-		throw error(std::format("{}: {}", filename.string(),
-					err.what()));
+	auto uclconfig = co_await ucl::parse(config_text);
+
+	for (auto &&[key, value] : uclconfig) {
+		auto opt = co_await store::get().fetch(key);
+		co_await opt->ucl(value);
 	}
 
-	return {};
+	co_return {};
 }
 
 } // namespace nihil::config