added some sort of error generation when parsing

errors occur

src/ast/errors/error.hpp

@@ -0,0 +1,25 @@
+#pragma once
+
+#include "token/type.hpp"
+
+namespace ast::error {
+    struct error : public std::runtime_error {
+        explicit error(const std::string& message)
+            : std::runtime_error(message) {}
+    };
+
+    struct parser_error : error {
+        explicit parser_error(const std::string& message): error(message) {}
+    };
+
+    struct expected_next : parser_error {
+        token::type expected_type;
+
+        explicit expected_next(
+            token::type expected_type, const std::string& message
+        )
+            : parser_error(message),
+              expected_type(expected_type) {}
+    };
+
+} // namespace ast::error