Improving adaparse (#320)

Author: lemire

tools/CMakeLists.txt

@@ -1,3 +1,7 @@
 add_executable(adaparse adaparse.cpp)
 target_link_libraries(adaparse PRIVATE ada)
 target_include_directories(adaparse PUBLIC "$<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>")
+
+import_dependency(cxxopts jarro2783/cxxopts eb78730)
+add_dependency(cxxopts)
+target_link_libraries(adaparse PRIVATE cxxopts::cxxopts)

tools/adaparse.cpp

@@ -1,7 +1,7 @@
 #include <cstdlib>
 #include <iostream>
 #include <string_view>
-
+#include <cxxopts.hpp>
 #include "ada.h"
 /**
  * @private
@@ -39,18 +39,23 @@
  *      `-------------------------------- protocol_end 5
  **/
 int main(int argc, char** argv) {
-  if (argc < 2) {
-    std::cout << "use a URL as a parameter." << std::endl;
+  cxxopts::Options options("adaparse",
+                           "Command-line version of the Ada URL parser");
+
+  options.add_options()("d,diagram", "Print a diagram of the result",
+                        cxxopts::value<bool>()->default_value("false"))(
+      "u,url", "URL Parameter (required)", cxxopts::value<std::string>())(
+      "h,help", "Print usage");
+  options.parse_positional({"url"});
+
+  auto result = options.parse(argc, argv);
+  // the first argument without an option name will be parsed into file
+  if (result.count("help") || !result.count("url")) {
+    std::cout << options.help() << std::endl;
     return EXIT_SUCCESS;
   }
-  std::string url_string = argv[1];
-  bool to_diagram = false;
-  if (argc > 2) {
-    if (std::string_view(argv[1]) == "-d") {
-      url_string = argv[2];
-      to_diagram = true;
-    }
-  }
+  std::string url_string = result["url"].as<std::string>();
+  bool to_diagram = result["diagram"].as<bool>();
   ada::result<ada::url_aggregator> url = ada::parse(url_string);
   if (!url) {
     std::cerr << "Invalid." << std::endl;