fix(parser): made it compile

src/parser/parsing_utils.h

@@ -18,6 +18,11 @@
         puts("Internal error: cannot get the following token");                \
         return NULL;                                                           \
     }
+
+/* @brief: parses a list of [and_or] rules, separated by semicolons.
+ */
+struct ast *parse_list(void);
+
 /* @brief Parses a simple list of words (command and arguments)
  * and returns the resulting ast
  */
@@ -44,4 +49,4 @@ struct ast* parse_and_or(void);
  */
 struct ast* parse_else_clause(void);
 
-#define /* ! PARSING_UTILS_H */
+#endif /* ! PARSING_UTILS_H */