Describe the enhancement

I'd like some kind of conditional operation added to expression syntax. This can be an actual ternary operator (? :) or a built-in function (e.g., if(<condition>, <true-value>, <false-value>)).

Additional information

There is a workaround: using shell scripts to evaluate the condition, setting step outputs, and having other steps reference those outputs. But it would be much cleaner to have some kind of ternary / if/then/else / conditional branching built in to the expression syntax.