local function parse(arg, config)

	local short_params = config and config.short_params or {};

	local value_params = config and config.value_params or {};

	local array_params = config and config.array_params or {};

	local parsed_opts = {};

	if #arg == 0 then

		return parsed_opts;

	end

	while true do

		local raw_param = arg[1];

		if not raw_param then

			break;

		end

		local prefix = raw_param:match("^%-%-?");

		if not prefix then

			break;

		elseif prefix == "--" and raw_param == "--" then

			table.remove(arg, 1);

			break;

		end

		local param = table.remove(arg, 1):sub(#prefix+1);

		if #param == 1 and short_params then

			param = short_params[param];

		end

		if not param then

			return nil, "param-not-found", raw_param;

		end

		local param_k, param_v;

		if value_params[param] or array_params[param] then

			param_k, param_v = param, table.remove(arg, 1);

			if not param_v then

				return nil, "missing-value", raw_param;

			end

		else

			param_k, param_v = param:match("^([^=]+)=(.+)$");

			if not param_k then

				if param:match("^no%-") then

					param_k, param_v = param:sub(4), false;

				else

					param_k, param_v = param, true;

				end

			end

			param_k = param_k:gsub("%-", "_");

		end

		if array_params[param] then

			if parsed_opts[param_k] then

				table.insert(parsed_opts[param_k], param_v);

			else

				parsed_opts[param_k] = { param_v };

			end

		else

			parsed_opts[param_k] = param_v;

		end

	end

	for i = 1, #arg do

		parsed_opts[i] = arg[i];

	end

	return parsed_opts;

end

return {

	parse = parse;

}