Which style is more readable depends on whether in practice you end up with more sequence-like structures, or more tree-like structures. Chaining makes sense fo

Which style is more readable depends on whether in practice you end up with more sequence-like structures, or more tree-like structures. Chaining makes sense for sequences. For tree-like structures, they get confusing because the nesting levels aren't apparent. For example: In your code sample, it's a bit unclear what nesting level the .and() call is occurring at. It could be a method call from the chain that starts at secondVar, or the chain that starts at firstFar. Distinguishing which one requires counting all the intervening parentheses. This okay for the given example, but gets out of hand as the conditions get complicated. Ergonomics aside, I don't think the prefix notation is unintuitive. It's a bit verbose, since JavaScript doesn't have operator overloading, but to me it seems the most sensible and straightforward way of structuring the relationships.