Scan =

src/lexer.rs

         Matcher::new(r#"^[0-9]+"#, TokenType::Number),
         Matcher::new(r#"^\*"#, TokenType::Star),
         Matcher::new(r#"^,"#, TokenType::Comma),
+        Matcher::new(r#"^="#, TokenType::Equals),
     ];
 }
 
         assert_eq!(scan(",").unwrap(), vec![Token::new(TokenType::Comma, ",")])
     }
 
+    #[test]
+    fn it_scans_an_equals_sign() {
+        assert_eq!(scan("=").unwrap(), vec![Token::new(TokenType::Equals, "=")])
+    }
+
     #[test]
     fn it_allows_dots_in_identifiers() {
         assert_eq!(

src/token.rs

 pub enum TokenType {
     Comma,
     From,
+    Equals,
     Identfiier,
     Number,
     Select,
             "{}",
             match self {
                 TokenType::Comma => "Comma",
+                TokenType::Equals => "Equals",
                 TokenType::Identfiier => "Identifier",
                 TokenType::Number => "Number",
                 TokenType::Star => "Star",