diff --git a/src/lexer/mod.rs b/src/lexer/mod.rs
index 87d88db..706c91e 100644
--- a/src/lexer/mod.rs
+++ b/src/lexer/mod.rs
@@ -18,6 +18,8 @@ use self::str::RelativeIndexable;
 use self::token::Lex;
 use self::token::Token;
 
+type StateResult = Result<Option<Token>, String>;
+
 #[derive(Debug)]
 enum State {
     Comment,