Don't attempt to parse empty token streams

Program.cs

@@ -39,6 +39,10 @@ public class Program
 				Console.WriteLine($"{token.region}: {token.type} {{{token.data}}}");
 			}
 		}
+		if(tokens.Length == 0)
+		{
+			return;
+		}
 		if(Path.GetFileName(file).StartsWith("tokenizer"))
 		{
 			Console.WriteLine($"Skipping parsing of `{file}`");