better eval and test for eval,quote

tests/test_vars.rs

@@ -265,4 +265,36 @@ mod var_lib_tests {
         eval(&env_tree, &mut syms).unwrap();
         eval(&tst_tree, &mut syms).unwrap();
     }
+
+    #[test]
+    fn test_quote() {
+        let document = "(quote (add 1 2))";
+        let result = "(add 1 2)";
+        let mut syms = SymTable::new();
+        static_stdlib(&mut syms).unwrap();
+        dynamic_stdlib(&mut syms).unwrap();
+        assert_eq!(
+            *eval(&lex(&document.to_string()).unwrap(), &mut syms)
+                .unwrap()
+                .to_string(),
+            result.to_string(),
+        );
+    }
+
+    #[test]
+    fn test_eval() {
+        let document = "
+          (let ((stored-tree (quote (add 1 2))))
+            (eval stored-tree)))";
+        let result = "3";
+        let mut syms = SymTable::new();
+        static_stdlib(&mut syms).unwrap();
+        dynamic_stdlib(&mut syms).unwrap();
+        assert_eq!(
+            *eval(&lex(&document.to_string()).unwrap(), &mut syms)
+                .unwrap()
+                .to_string(),
+            result.to_string(),
+        );
+    }
 }