ArgumentParse.h

/*
Copyright (c) <2018> <doug gray>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

// process command line options
// example of two argument option:
//   procFlag("-x", arglist, option1, option2);  // arglist=vector<strings), option1= first variable, option2=second variable
// variables may be either strings, ints, doubles, or bools. Bools do not remove an argument but set option variable to true
// other variables are set with converted argument strings which are then removed

#include <vector>
#include <string>
#include <type_traits>


std::vector<std::string> vectorize_commands(int argc, const char **pargs) {
    std::vector<std::string> cmdArgs;
    for (int i = 0; i < argc; i++) // place command line arguments in string vector
        cmdArgs.push_back(pargs[i]);
    return cmdArgs;
}


namespace ArgHelp {
	void fixup(const std::string &argcmd, bool& arg) {}	// dummy, bool variable set by procFlag(), no arg consumed
	void fixup(const std::string &argcmd, std::string &arg) { arg = argcmd; }
	template<class T>
	std::enable_if_t<std::is_floating_point<T>::value>
		fixup(const std::string &argcmd, T& arg) { arg = static_cast<T>(stod(argcmd)); }
	template<class T>
	std::enable_if_t<std::is_integral<T>::value>
		fixup(const std::string &argcmd, T& arg) { arg = stoi(argcmd); }

	template<class T>
	void procVal(std::vector<std::string>& arglist, int idx, T& arg)
	{
		fixup(arglist[idx], arg);
		arglist.erase(arglist.begin() + idx);
	}
	void procVal(std::vector<std::string>&, int) {}  // nothing more to do, end option search

	template<class T, class ...TA>
	void procVal(std::vector<std::string>& arglist, int idx, T& arg, TA&...argv)
	{
		procVal(arglist, idx, arg);     // process an argument
		procVal(arglist, idx, argv...); // then process another argument
	}
}

template<class T, class ...TA>
bool procFlag(const char *pc, std::vector<std::string>& arglist, T& arg1, TA&...argv)
{
	using namespace ArgHelp;
	std::string flag(pc);
	if (flag[0] != '-' || flag.length() != 2)
		throw std::invalid_argument(flag);
    
    // bools may be concatinated, remove if a match is found
	if (std::is_same<bool, T>::value)
	{
        for (int i = 0; i < arglist.size(); i++)
        {
            if (arglist[i][0] == '-')   // may be flag or negative numerical argument
            {
                for (int ii = 1; ii < arglist[i].length(); ii++)
                {
                    if (arglist[i][ii] == flag[1])
                    {
                        arg1 = true;
                        if (arglist[i].length() == 2)
                            arglist.erase(arglist.begin() + i);
                        else
                            arglist[i].erase(ii,1);
                        return true;
                    }
                }
            }
        }
	}
	for (int i = 0; i < arglist.size(); i++)
	{
		if (arglist[i] == flag)
		{
			arglist.erase(arglist.begin() + i);
			procVal(arglist, i, arg1);		// process one argument after flag
			procVal(arglist, i, argv...);	// process more arguments, if any, after flag
			return true;
		}
	}
	return false;
}

#if 0
// ArgumentParse Test
bool procFlagTest()
{
    int pass = 0;
    {
        vector<string> args{
            "-abc",
            "-x", "3.0",
            "-de",
            "-s", "Hello There",
            "-y", "4.5", "4.6",
            "-z", "100",
            "-f"
        };
        bool a, b, c, d, e, f;
        int z1;
        float x1;
        double y1, y2;
        string s;
        procFlag("-a", args, a);
        procFlag("-b", args, b);
        procFlag("-c", args, c);
        procFlag("-d", args, d);
        procFlag("-s", args, s);
        procFlag("-e", args, e);
        procFlag("-x", args, x1);
        procFlag("-f", args, f);
        procFlag("-y", args, y1, y2);
        procFlag("-z", args, z1);
        pass++;
    }
    {
        vector<string> args{
            "-s", "Hello There",
            "-abc",
            "-x", "3.0",
            "-de",
            "-y", "4.5", "4.6",
            "-z", "100",
            "-f"
        };
        bool a, b, c, d, e, f;
        int z1;
        float x1;
        double y1, y2;
        string s;
        procFlag("-y", args, y1, y2);
        procFlag("-z", args, z1);
        procFlag("-b", args, b);
        procFlag("-s", args, s);
        procFlag("-c", args, c);
        procFlag("-a", args, a);
        procFlag("-d", args, d);
        procFlag("-e", args, e);
        procFlag("-x", args, x1);
        procFlag("-f", args, f);
        pass++;
    }
    return true;
}
#endif