Add option to load file on startup.

stateful_dice/main.cxx

@@ -20,15 +20,22 @@ void usage() {
   std::cout << "'1d6+$Dex'  : Roll 1d6 plus whatever value subs for 'Dex'\n";
 }
 
-void print_binding(std::pair<const std::string, std::string> const & pair,
-                   std::ostream & os = std::cout) {
+void print_binding_os(std::pair<const std::string, std::string> const & pair,
+                      std::ostream & os) {
   os << pair.first;
   if (pair.second == "") os << " is not defined\n";
   else os << " := " << pair.second << "\n";
 }
 
+void print_binding(std::pair<const std::string, std::string> const & pair) {
+  print_binding_os(pair, std::cout);
+}
+
 class evaluator {
 public:
+  evaluator(std::string const & path = "") {
+    if (!path.empty()) { load(path); }
+  }
   void operator()(std::string const & str);
  
 private:
@@ -47,7 +54,7 @@ private:
     using namespace std::placeholders;
     std::ofstream out(file);
     std::for_each(bindings.begin(), bindings.end(),
-                  std::bind(&print_binding, _1, std::ref(out)));
+                  std::bind(&print_binding_os, _1, std::ref(out)));
   }
   void load(std::string const & file) {
     std::ifstream in(file);
@@ -98,10 +105,10 @@ void evaluator::operator()(std::string const & str) {
 }
 
 
-int main(int, const char **) {
+int main(int argc, const char * argv[]) {
   std::string line;
   std::cout << "> ";
-  evaluator eval;
+  evaluator eval(argc > 1 ? argv[1] : "");
   while (std::getline(std::cin, line)) {
     eval(line);
     std::cout << "> ";