toggle to show input as bytes or text

src/marble_engine.rs

@@ -58,6 +58,10 @@ impl Machine {
 		&self.input
 	}
 
+	pub fn input_index(&self) -> usize {
+		self.input_index
+	}
+
 	pub fn step_count(&self) -> usize {
 		self.steps
 	}