From a5951731e49a6884f42c2a07c9e65355831b4394 Mon Sep 17 00:00:00 2001
From: Bent Bisballe Nyeng <deva@aasimon.org>
Date: Mon, 24 Feb 2025 20:51:43 +0100
Subject: WIP

---
 src/argparser.h | 77 ++++++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 57 insertions(+), 20 deletions(-)

(limited to 'src/argparser.h')

diff --git a/src/argparser.h b/src/argparser.h
index 51d6745..ec7d5ce 100644
--- a/src/argparser.h
+++ b/src/argparser.h
@@ -10,8 +10,31 @@
 #include <type_traits>
 #include <iostream>
 
+namespace arg
+{
+struct noarg {};
+template<typename T>
+struct Opt
+{
+	std::string shortopt;
+	std::string longopt;
+	std::function<int(T)> cb;
+	std::string help;
+	T t{};
+};
+
+template<>
+struct Opt<noarg>
+{
+	std::string shortopt;
+	std::string longopt;
+	std::function<int()> cb;
+	std::string help;
+	noarg t{};
+};
+
 template<typename... Ts>
-class ArgParser
+class Parser
 {
 public:
 	struct missing_arg{};
@@ -22,6 +45,7 @@ public:
 		{
 			return 1;
 		}
+
 		for(int i = 1; i < argc; ++i) // skip argv[0] which is program name
 		{
 			bool was_handled{false};
@@ -38,20 +62,33 @@ public:
 						           }
 						           try
 						           {
-							           auto arg = convert(argc, argv, i, opt.t);
-							           return {opt.cb(arg), state::handled};
+							           using T = std::decay_t<decltype(opt)>;
+							           if constexpr (std::is_same_v<T, Opt<noarg>>)
+							           {
+								           return {opt.cb(), state::handled};
+							           }
+							           else
+							           {
+								           auto arg = convert(argc, argv, i, opt.t);
+								           return {opt.cb(arg), state::handled};
+							           }
 						           }
 						           catch(std::invalid_argument&)
 						           {
-							           std::cout << "Invalid " << opt.shortopt <<
-								           " argument.\n";
-							           std::cout << opt.help << "\n";
+							           std::cout << argv[0] <<
+								           ": invalid argument for option '" <<
+								           opt.shortopt << "'\n";
+							           std::cout << "Type '" << argv[0] <<
+								           " -h' for more information.\n";
 							           return {1, state::handled};
 						           }
 						           catch(missing_arg&)
 						           {
-							           std::cout << "Missing " << opt.shortopt <<
-								           " argument.\n";
+							           std::cout << argv[0] <<
+								           ": option requires and argument '" <<
+								           opt.shortopt << "'\n";
+							           std::cout << "Type '" << argv[0] <<
+								           " -h' for more information.\n";
 							           std::cout << opt.help << "\n";
 							           return {1, state::handled};
 						           }
@@ -69,7 +106,8 @@ public:
 			}
 			if(!was_handled)
 			{
-				std::cout << "Unknown argument " << argv[i] << '\n';
+				std::cout << argv[0] << ": invalid option '" << argv[i] << "'\n";
+				std::cout << "Type '" << argv[0] << " -h' for more information.\n";
 				return 1;
 			}
 		}
@@ -85,18 +123,15 @@ public:
 		options.emplace_back(Opt<T>{shortopt, longopt, cb, help});
 	}
 
-private:
-	template<typename T>
-	struct Opt
+	void add(const std::string& shortopt,
+	         const std::string& longopt,
+	         std::function<int()> cb,
+	         const std::string& help)
 	{
-		//using contained_type = T;
-		std::string shortopt;
-		std::string longopt;
-		std::function<int(T)> cb;
-		std::string help;
-		T t{};
-	};
+		options.emplace_back(Opt<noarg>{shortopt, longopt, cb, help});
+	}
 
+private:
 	template<typename T>
 	T convert(int argc, const char* const argv[], int& i, T)
 	{
@@ -148,6 +183,8 @@ private:
 		return {};
 	}
 
-	using Opts = std::variant<Opt<Ts>...>;
+	using Opts = std::variant<Opt<noarg>, Opt<Ts>...>;
 	std::vector<Opts> options;
 };
+
+} // arg::
-- 
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