part of type checker, type heck result type

include/error_log.hpp

@@ -0,0 +1,74 @@
+#pragma once
+
+#include "basic_nodes.hpp"
+#include "basic_printers.hpp"
+
+#include <vector>
+
+namespace error_handling {
+
+enum class ErrorType {
+  GENERAL,
+  TYPE_CHECK,
+};
+
+inline std::string to_string(ErrorType error_type) {
+  switch (error_type) {
+  case ErrorType::GENERAL:
+    return "general error";
+  case ErrorType::TYPE_CHECK:
+    return "type check error";
+  }
+}
+
+class ErrorLog {
+public:
+  struct ErrorMessage {
+  public:
+    ErrorMessage(nodes::Node node, const std::string &message,
+                 ErrorType error_type = ErrorType::GENERAL)
+        : node_(node), message_(message), error_type_(error_type) {}
+
+    void print(printers::Printer &printer) {
+      printer.print("Error at ");
+      print_position(printer, node_.get_start_position(),
+                     node_.get_start_position());
+      printer.print(" : ");
+      printer.print(message_);
+      printer.print(" (" + to_string(error_type_) + ").");
+    }
+
+  private:
+    inline void print_position(printers::Printer &printer,
+                               std::pair<size_t, size_t> start_position,
+                               std::pair<size_t, size_t> end_position) {
+      printer.print("[" + std::to_string(start_position.first + 1) + ", " +
+                    std::to_string(start_position.second + 1) + "] - [" +
+                    std::to_string(end_position.first + 1) + ", " +
+                    std::to_string(end_position.second + 1) + "]");
+    }
+
+  public:
+    nodes::Node node_;
+    std::string message_;
+    ErrorType error_type_ = ErrorType::GENERAL;
+  };
+
+  void add_error(ErrorMessage &&error) {
+    messages_.push_back(std::move(error));
+  }
+
+  void add_error(const ErrorMessage &error) { messages_.push_back(error); }
+
+  void print_all_errors(printers::Printer &printer) {
+    for (auto &message : messages_) {
+      message.print(printer);
+      printer.new_indent_line();
+    }
+  }
+
+private:
+  std::vector<ErrorMessage> messages_;
+};
+
+} // namespace error_handling