Your point seems to be more about using chains of set operators rather than the fact that it is on one line.<p>I am a C# guy and I find Linq which is the equivalent to this insanely useful and I often write code as above. The tax on this is the rest of the team need to be up to speed in reading such code. If they are then what you gain is use of a bunch of predictable operators rather than loops with counters, state, etc... that could have subtle bugs.<p>Using code like this is no different to writing SQL that does joins and aggregates in a stored procedure and calling it from your code, something I also thing isn&#x27;t a bad thing.<p>Debugging can be done by splitting it into lines, or using a decent enough debugger. Or making it pure and writing unit tests or property-based tests to cover it.