Initial commit

core-library/views/command-line-args-view.h

@@ -0,0 +1,95 @@
+#pragma once
+#include <ranges>
+#include <span>
+#include <string_view>
+
+namespace core {
+
+class command_line_argument
+{
+public:
+	constexpr command_line_argument(char* arg, std::span<char*> modifiers)
+	: m_arg_view{arg}
+	, m_modifiers{modifiers}
+	{
+	}
+
+	template<typename F>
+		requires std::invocable<F>
+	void with(std::string_view arg_to_match_view, F&& function) const
+	{
+		if (arg_to_match_view == m_arg_view)
+			std::invoke(std::forward<F>(function));
+	}
+
+private:
+	std::string_view m_arg_view;
+	std::span<char*> m_modifiers;
+};
+
+class command_line_args_view : public std::ranges::view_interface<command_line_args_view>
+{
+public:
+	constexpr command_line_args_view() = default;
+
+	constexpr command_line_args_view(int argc, char* argv[])
+	: m_argc{--argc}
+	, m_application_path{argv++[0]}
+	, m_argv{argv}
+	{
+	}
+
+	class iterator
+	{
+	public:
+		constexpr iterator(int argc, char** argv, int index)
+		: m_argv{argv}
+		, m_argc{argc}
+		, m_index{index}
+		{
+		}
+
+		constexpr iterator& operator++()
+		{
+			++m_index;
+
+			while (m_index < m_argc)
+			{
+				const std::string_view arg_view{m_argv[m_index]};
+				if (arg_view.starts_with("--"))
+					m_modifier_start_index = m_index++;
+			}
+
+			return *this;
+		}
+
+		constexpr command_line_argument operator*() const
+		{
+			if (m_modifier_start_index != -1)
+				return command_line_argument{m_argv[m_index], std::span<char*>(&m_argv[m_modifier_start_index], &m_argv[m_index])};
+			else
+				return command_line_argument{m_argv[m_index], {}};
+		}
+
+		constexpr bool operator!=(const iterator& other) const { return m_argv != other.m_argv || m_index != other.m_index; }
+
+	private:
+		char** m_argv;
+		int    m_argc;
+		int    m_index;
+		int    m_modifier_start_index{-1};
+	};
+
+	constexpr auto&& appliation_path() const { return m_application_path; }
+
+	constexpr iterator    begin() const { return iterator{m_argc, m_argv, 0}; }
+	constexpr iterator    end() const { return iterator{m_argc, m_argv, m_argc}; }
+	constexpr std::size_t size() const { return static_cast<std::size_t>(m_argc); }
+
+private:
+	int    m_argc{};
+	char*  m_application_path{};
+	char** m_argv{};
+};
+
+}