I agree with you that helper functions within configuration are a code smell, but I find (immutable) temporary variables helpful. It's pretty common to want na

I agree with you that helper functions within configuration are a code smell, but I find (immutable) temporary variables helpful. It's pretty common to want named constants to avoid copy-pasting configuration and to make consistent modification easier. You could have an inclusion mechanism and put those constant parts in their own configuration file, but then you've effectively renamed "my_constant" to "include('my_constant.cfg')". Immutable temporary variables are just non-globally scoped constants.