cli.hpp

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/*
 * Copyright (C) 2023  Christopher J. Howard
 *
 * This file is part of Antkeeper source code.
 *
 * Antkeeper source code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Antkeeper source code is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Antkeeper source code.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#ifndef ANTKEEPER_DEBUG_CLI_HPP
#define ANTKEEPER_DEBUG_CLI_HPP
 
#include <functional>
#include <sstream>
#include <string>
#include <tuple>
#include <type_traits>
#include <unordered_map>
 
namespace debug {
 
class cli
{
public:
    std::string interpret(const std::string& line) const;
    
    template <class T, class... Args>
    void register_command(const std::string& name, const std::function<T(Args...)>& function);
    template <class T, class... Args>
    void register_command(const std::string& name, T (*function)(Args...));
    
    void unregister_command(const std::string& name);
    
private:
    typedef std::function<std::string(const std::string&)> command_type;
    
    template <class T>
    [[nodiscard]] static T parse(std::istringstream& stream);
    
    template <class T, class... Args>
    [[nodiscard]] static command_type wrap(std::function<T(Args...)> function);
    
    std::unordered_map<std::string, command_type> commands;
};
 
template <class T, class... Args>
void cli::register_command(const std::string& name, const std::function<T(Args...)>& function)
{
    commands[name] = wrap(function);
}
 
template <class T, class... Args>
void cli::register_command(const std::string& name, T (*function)(Args...))
{
    commands[name] = wrap(std::function(function));
}
 
template <class T>
T cli::parse(std::istringstream& stream)
{
    T value;
    stream >> value;
    return value;
}
 
template <class T, class... Args>
typename cli::command_type cli::wrap(std::function<T(Args...)> function)
{
    return std::bind
    (
        [function](const std::string& line) -> std::string
        {
            //constexpr std::size_t argument_count = sizeof...(Args);
            
            // Parse string into tuple of arguments
            std::istringstream istream(line);
            std::tuple<Args...> arguments{parse<Args>(istream)...};
            
            if constexpr(std::is_void_v<T>)
            {
                // Invoke function with parsed arguments
                std::apply(function, arguments);
                
                // Return empty string
                return std::string();
            }
            else
            {
                // Invoke function with parsed arguments and save the result
                T result = std::apply(function, arguments);
                
                // Return invocation result as a string
                std::ostringstream ostream;
                ostream << result;
                return ostream.str();
            }
        },
        std::placeholders::_1
    );
}
 
} // namespace debug
 
#endif // ANTKEEPER_DEBUG_CLI_HPP