Fix positions.

src/tokenizer.rs

@@ -257,16 +257,19 @@ impl fmt::Display for Position {
 
 impl fmt::Debug for Position {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        #[cfg(not(feature = "no_position"))]
-        if self.is_beginning_of_line() {
-            write!(f, "{}", self.line)?;
+        if self.is_none() {
+            f.write_str("none")
         } else {
-            write!(f, "{}:{}", self.line, self.pos)?;
-        }
-        #[cfg(feature = "no_position")]
-        f.write_str("none")?;
+            #[cfg(not(feature = "no_position"))]
+            if self.is_beginning_of_line() {
+                write!(f, "{}", self.line)
+            } else {
+                write!(f, "{}:{}", self.line, self.pos)
+            }
 
-        Ok(())
+            #[cfg(feature = "no_position")]
+            unreachable!();
+        }
     }
 }