? timer
  # value: <a Timer>
  
  ? def t := timer.now(); t =~ tt :int ? (t == tt)
  # value: true
  
  ? t > 1117718697755
  # value: true
  
  ? timer.now() >= t
  # value: true
  
  ? def r1 := timer.whenPast(def expected := timer.now() + 1000, thunk {
  >   def delta := timer.now() - expected
  >   println(`thunk 1 (${if (delta > 500) {delta}})`)
  >   11
  > })
  # value: <Promise>
  
  ? interp.waitAtTop(r1); r1
  # value: <Promise>
  
  # stdout: thunk 1 (null)
  #

  ? timer.now() > (t + 1000)
  # value: true
    
  ? r1
  # value: 11

  ? def r2 := timer.whenPast((def base := timer.now()) + 2000, thunk {println("timing test 1")})
  # value: <Promise>
    
  ? def r3 := timer.whenPast(base + 1000, thunk {println("timing test 2")})
  # value: <Promise>
  
  ? interp.waitAtTop(r2)
  
  # stdout: timing test 2
  #         timing test 1
  #