How to not fall into R's 'lazy evaluation trap'

Question

\"R passes promises, not values. The promise is forced when it is first evaluated, not when it is passed.\", see this answer by G. Grothendieck. Also see this question referring

Answer 1

There is some work in progress to improve R's higher order functions like the apply functions, Reduce, and such in handling situations like these. Whether this makes into R 3.2.0 to be released in a few weeks depend on how disruptive the changes turn out to be. Should become clear in a week or so.