diff --git a/src/scanner.rs b/src/scanner.rs
index af4441b..c8e62e2 100644
--- a/src/scanner.rs
+++ b/src/scanner.rs
@@ -81,6 +81,11 @@ impl Scanner {
         }
     }
 
+    /// Check whether the end of the input has been reached.
+    fn is_at_end(&self) -> bool {
+        self.current >= self.len
+    }
+
     /// Advance to the next character and return it.
     fn advance(&mut self) -> char {
         let ch = self.cur_char();
@@ -105,11 +110,6 @@ impl Scanner {
         self.source.chars().nth(self.current).unwrap()
     }
 
-    /// Check whether the end of the input has been reached.
-    fn is_at_end(&self) -> bool {
-        self.current >= self.len
-    }
-
     /// Add a token to the output.
     fn add_token(&mut self, token_type: TokenType) {
         let lexeme = self