Is there a way to run an expression on.exit() but only if completes normally, not on error?

Question

I\'m aware of the function on.exit in R, which is great. It runs the expression when the calling function exits, either normally or as the result of an error.

Answer 1

Bit more readable version of my comment on @Joris' answer:

f = function() {
  ret = local({
    myvar = 42
    if (runif(1) < 0.5)
      return(2)
    stop('oh noes')
  }, environment())
  # code to run on success...
  print(sprintf('myvar is %d', myvar))
  ret
}