fixup! Split main by files

src/tokenizer.rs

@@ -19,7 +19,7 @@ pub fn tokenizer(task: &str) -> Vec<Token> {
   while pointer < task.len() {
     let c = chars[pointer];
     match c {
-      '0' .. '9' => {
+      '0' ..='9' => {
         let mut end = pointer;
         while end < task.len() {
           let cur_c = chars[end];