Argument parsing simplification

[kloetzl]

Hi,

I noticed that your argument parsing is unnecessarily complex. Here are two ideas to make it simpler. First, you have a lot of repetitive code, just checking for simple flags. Using a vector a lot of that can be folded away.

int main(int argc, char **argv){
	auto simple_flags = std::vector<std::pair<std::string,bool&>>({
		{"-a_cob", APPROX_CUT_ONE_B},
		{"-a_c2b", APPROX_CUT_TWO_B},
		{"-a_c2br", APPROX_CUT_TWO_B_ROOT} // ToDo: list all other flags
	});

	int max_args = argc-1;
	while (argc > 1) {
		char *arg = argv[--argc];
		auto it = std::find_if(simple_flags.begin(), simple_flags.end(), [=](const std::pair<std::string,bool&>& flag){
			return flag.first == arg;
		});
		if (it != simple_flags.end()) {
			it->second = true;
			continue;
		}

		// deal with more complicated flags …
	}

	// rest of main …
}

Second, for -pairwise you use a lot of nested ifs. Inverting the logic here can help.

else if (strcmp(arg, "-pairwise") == 0)
{
	PAIRWISE = true;
	QUIET = true;

	do {
		if (max_args <= argc)break;
		if (argv[argc + 1][0] == '-') break;

		PAIRWISE_START = atoi(argv[argc + 1]);

		if (max_args <= argc + 1)break;
		if (argv[argc + 2][0] == '-') break;

		PAIRWISE_END = atoi(argv[argc + 2]);

		if (max_args <= argc + 2)break;
		if (argv[argc + 3][0] == '-') break;

		PAIRWISE_COL_START = atoi(argv[argc + 3]);

		if (max_args <= argc + 3)break;
		if (argv[argc + 4][0] == '-') break;

		PAIRWISE_COL_END = atoi(argv[argc + 4]);
	} while (0);
}

Best,
Fabian