[R] delayedAssign list members

I am fascinated by lazy evaluation mechanism provided by delayedAssign. Like delayedAssign(foo, { Sys.sleep(1) # or any other time consuming operations 1 } Time consuming operations will be evaluated only if object foo is used. But when I try: foo - list() foo$bar - 1

Re: [R] delayedAssign list members

delayedAssign(foo$bar, 2) foo$bar # 1 `foo$bar` # 2 Yes, you assign to the new variable `foo$bar`, not to bar component of the foo variable! You can use an environment for doing what you want: e - new.env() e$bar - 1 delayedAssign(bar, 2, assign.env = e) e$bar But notice also the