refactor(ast): one file per ast_type -- UNSTABLE (3)

src/utils/ast/ast.h

@@ -27,4 +27,15 @@ struct ast
     void *data;
 };
 
+/* @brief: returns an ast* with corresponding data and type.
+ *
+ * @note: this function should only be called by ast_create_[TYPE] functions.
+ */
+struct ast *ast_create(enum ast_type type, void *data);
+
+/* @brief: frees the given ast. If ast is NULL, does nothing.
+ *
+ */
+void ast_free(struct ast *node)
+
 #endif /* ! AST_H */