typedef enum {
    Error_Type_Ill_Formed_List,
    Error_Type_Ill_Formed_Arguments,
    Error_Type_Ill_Formed_Lambda_List,
    Error_Type_Wrong_Number_Of_Arguments,
    Error_Type_Unknown_Keyword_Argument,
    Error_Type_Type_Missmatch,
    Error_Type_Symbol_Not_Defined,
    Error_Type_Not_A_Function,
    Error_Type_Not_Yet_Implemented,
    Error_Type_Syntax_Error,
    Error_Type_Unexpected_Eof,
    Error_Type_Unbalanced_Parenthesis,
    Error_Type_Trailing_Garbage,
    Error_Type_Unknown_Error,
} Error_Type;

typedef struct {
    Error_Type type;
    Ast_Node*  location;
} Error;

Error* error;

void delete_error() {
    if (error) {
        free(error);
        error = nullptr;
    }
}

void create_error(Error_Type type, Ast_Node* location) {
    delete_error();

    error = new(Error);
    error->type = type;
    error->location = location;
}

char* Error_Type_to_string(Error_Type type) {
    switch (type) {
    case Error_Type_Ill_Formed_List:           return "Evaluation-error: Ill formed list";
    case Error_Type_Ill_Formed_Arguments:      return "Evaluation-error: Ill formed arguments";
    case Error_Type_Ill_Formed_Lambda_List:    return "Evaluation-error: Ill formed lambda list";
    case Error_Type_Unknown_Keyword_Argument:  return "Evaluation-error: Unknown keyword argument";
    case Error_Type_Not_A_Function:            return "Evaluation-error: Not a function";
    case Error_Type_Symbol_Not_Defined:        return "Evaluation-error: Symbol not defined";
    case Error_Type_Wrong_Number_Of_Arguments: return "Evaluation-error: Wrong number of arguments";
    case Error_Type_Type_Missmatch:            return "Evaluation-error: Type Missmatch";
    case Error_Type_Not_Yet_Implemented:       return "Evaluation-error: Not yet implemented";
    case Error_Type_Trailing_Garbage:          return "Evaluation-error: Trailing garbage following expression";
    case Error_Type_Syntax_Error:              return "Syntax Error";
    case Error_Type_Unexpected_Eof:            return "Parsing-error: Unexpected EOF";
    case Error_Type_Unbalanced_Parenthesis:    return "Parsing-error: Unbalanced parenthesis";
    default:                                   return "Unknown Error";
    }
}