feat: code generation and execution for simple choice statements

src/main.zig

@@ -73,6 +73,9 @@ fn mainArgs(
         };
     };
 
+    const stdin = std.fs.File.stdin();
+    var stdin_reader = stdin.reader(&stdin_buffer);
+
     const stdout = std.fs.File.stdout();
     var stdout_writer = stdout.writer(&stdout_buffer);
 
@@ -89,11 +92,26 @@ fn mainArgs(
     try story.dump(&stderr_writer.interface);
     if (compile_only) return;
 
-    while (story.can_advance) {
-        const content = try story.advance();
-        defer gpa.free(content);
+    while (!story.is_exited and story.can_advance) {
+        while (story.can_advance) {
+            const content_text = try story.advance(gpa);
+            defer gpa.free(content_text);
+            std.debug.print("{s}\n", .{content_text});
+        }
+        if (story.current_choices.items.len > 0) {
+            for (story.current_choices.items, 0..) |*choice, index| {
+                const choice_text = try choice.text.toOwnedSlice(gpa);
+                defer gpa.free(choice_text);
+                std.debug.print("[{d}]: {s}\n", .{ index + 1, choice_text });
+            }
+            std.debug.print("> ", .{});
 
-        std.debug.print("{s}\n", .{content});
+            const input_line = try stdin_reader.interface.takeDelimiter('\n');
+            if (input_line) |bytes| {
+                const choice_index = try std.fmt.parseUnsigned(usize, bytes, 10);
+                try story.selectChoiceIndex(if (choice_index == 0) 0 else choice_index - 1);
+            }
+        }
     }
 }