```
2021.10.22 07:14:33.963099 [ 3451059 ] {} <Error> Application: DB::Exception: Syntax error (in file ./user_defined/function_a_function.sql): failed at position 39 ('->'): -> ch(2)

$ cat ./user_defined/function_a_function.sql
CREATE FUNCTION a_function AS tuple() -> ch(2)
```
{
    if (const auto * literal = node->as<ASTLiteral>())
    {
        if (literal->value.getType() == Field::Types::String)
        {
            auto string = applyVisitor(FieldVisitorToString(), literal->value);
            unsigned escaping = 0;
            for (auto c : string)
            {
                if (c == '\\')
                {
                    settings.ostr << c;
                    if (escaping == 2)
                        escaping = 0;
                    ++escaping;
                }
                else if (nullptr != strchr(metacharacters, c))
                {
                    if (escaping == 2)      
                        settings.ostr << c;
                    else                    
                        settings.ostr << "\033[1;35m" << c << "\033[0m";