Finish up the cli driver

spec.txt

@@ -96,3 +96,20 @@ I'm getting pretty frustrated with what I perceive to be bugs in the peg/leg par
 I don't really feel like maintaining it. And GNU Bison is like right there. If I can write a cfg for my little language
 here I'll switch. I also can't shake the feeling that this is over-engineered, and I really don't need a parser for all this, but
 oh well. I could probably do it all with just lex actually. Maybe I need to spend some time rethinking this.
+
+1/2/22
+
+Okay I decided to just power through, and I finished the CLI version, which I'll be committing with this update. I did write a CFG
+however I realized that since this isn't a programming language an LR parser isn't exactly right. I made the right choice with the
+PEG, I just need better tooling. Anyway the immediate problem that I was having was that I assumed that semantic actions following
+an optional term in leg would be run with a null pointer or not be run at all, but it turns out you need to wrap the semantic
+action in the optional as well. Oh well lesson learned. Maybe some day I'll write my own.
+
+Next up is definitely the Godot Native module. I've already read a bit about how to do it, but I know there will be a few hitches
+here and there. Also I want to convert the base module to use entirely c++ semantics, with the exception of printf since I'm not
+sure if there is a c++ parallel, which is a bit odd. C++ is weird, no wonder I've avoided using it until now. It seems like c++
+developers spend a lot of time coming up with new ways to do things, then declaring them unidomatic and banning them. I guess
+that's kind of a trend with higher level languages as they get older cough Java cough. Regardless, I need to learn it and this
+is as good of a project as any.
+
+Also I still haven't mentioned to Pam I was doing this. Hope that's not a problem...

src/base/cyoa.leg

@@ -153,22 +153,6 @@ void append_body(Page *page, char *str) {
   }
 }
 
-void print_page(Page *page) {
-  printf("HEADER: %s\nBODY: %s\n", page->id, page->body);
-  switch (page->footer.type) {
-  case FooterType::End:
-    printf("THE END\n");
-    break;
-  case FooterType::Goto:
-    printf("GOTO %s\n", page->footer.link);
-    break;
-  case FooterType::Choices:
-    printf("CHOICES:\n");
-    // TODO
-    break;
-  }
-}
-
 std::vector<Page*> CyoaParse(FILE *file) {
   yyin = file;
   yyparse();

src/base/storybook.cpp

@@ -56,10 +56,9 @@ void Storybook::Advance() {
   }
 }
 
-void Storybook::Advance(int choice_option) {
+void Storybook::Advance(int choice_option) { 
-  // TODO throw an exception if the ending type is not choices.
   if (!IsChoiceAvailable(choice_option)) {
-    // TODO throw exception?
+    throw IllegalChoiceException();
   }
   
   Choice* choice = (*current->footer.choices)[choice_option];
@@ -122,9 +121,13 @@ void Storybook::Play() {
     printf("Make a selection: ");
     int choice_option;
     std::cin >> choice_option;
-    Advance(choice_option);
+    try {
+      Advance(choice_option);
+    } catch (IllegalChoiceException e) {
+      printf("You can't do that!\n\n");
+    }
     break;
   default:
-    IsEnded = true; // TODO
+    IsEnded = true;
   }
 }

src/base/storybook.h

@@ -31,6 +31,12 @@ public:
 
   // This will probably be moved to the cli driver
   void Play();
+
+  class IllegalChoiceException : std::exception {
+    virtual const char *what() const noexcept {
+      return "Illegal Choice.";
+    }
+  };
 };
 
 #endif /* STORYBOOK_H */