While we could continue to introduce language primatives, I generally
want the language to remain minimal. If we end up with ternaries and
case statements, we're almost programming in YAML, and I explicitly
did not
want this to be a programming language.
For instance, the best way to not run some tasks on a particular group
is to not talk to that group of systems
Well, I personally find the 'in' syntax so expressive that it 'does not
look much like coding' to me. On the other hand, I would agree that
proper grouping of hosts is most of the time the best way to reduce
repetitive statements.
In all cases, it should be included in the documentation what kind of
python expressions and operators are supported by the 'only_if' option.