Scan WHERE

src/lexer.rs

         Matcher::new(r#"^"(.*)""#, TokenType::String),
         Matcher::new(r#"^SELECT"#, TokenType::Select),
         Matcher::new(r#"^FROM"#, TokenType::From),
+        Matcher::new(r#"^WHERE"#, TokenType::Where),
         Matcher::new(r#"^[a-z][a-zA-Z_\-.*]*"#, TokenType::Identfiier),
         Matcher::new(r#"^[0-9]+"#, TokenType::Number),
         Matcher::new(r#"^\*"#, TokenType::Star),
     }
 
     #[test]
-    fn it_scans_a_keyword() {
+    fn it_scans_keywords() {
         assert_eq!(
-            scan("SELECT").unwrap(),
-            vec![Token::new(TokenType::Select, "SELECT")]
-        )
-    }
-
-    #[test]
-    fn it_scans_two_keywords() {
-        assert_eq!(
-            scan("SELECT FROM").unwrap(),
+            scan("SELECT FROM WHERE").unwrap(),
             vec![
                 Token::new(TokenType::Select, "SELECT"),
-                Token::new(TokenType::From, "FROM")
+                Token::new(TokenType::From, "FROM"),
+                Token::new(TokenType::Where, "WHERE"),
             ]
         )
     }

src/token.rs

     Select,
     Star,
     String,
+    Where,
 }
 
 impl std::fmt::Display for TokenType {
 
                 TokenType::Select => "SELECT",
                 TokenType::From => "FROM",
+                TokenType::Where => "WHERE",
             }
         )
     }