**Use case**
`SELECT POSITION('/' IN s) FROM (SELECT 'Hello/World' AS s);`

The same as `position(s, '/')`

{
    ParserIdentifier non_parametric;
    ParserIdentifierWithParameters parametric;
    if (parametric.parse(pos, node, expected))
    {
        auto * func = node->as<ASTFunction>();
        func->no_empty_args = true;
        return true;
    }
    ASTPtr ident;
    if (non_parametric.parse(pos, ident, expected))
    {
        auto func = std::make_shared<ASTFunction>();
        tryGetIdentifierNameInto(ident, func->name);
        func->no_empty_args = true;
        node = func;
        return true;
    }
    return false;
}
}