###
Convert complex z to polar form

  Input:    push  z

  Output:    Result on stack

  polar(z) = abs(z) * exp(i * arg(z))
###



Eval_polar = ->
  push(cadr(p1))
  Eval()
  polar()

polar = ->
  # there are points where we turn polar
  # representations into rect, we set a "stack flag"
  # here to avoid that, so we don't undo the
  # work that we are trying to do.
  evaluatingPolar++
  save()
  p1 = pop()
  push(p1)
  abs()
  push(imaginaryunit)
  push(p1)
  arg()
  multiply()
  exponential()
  multiply()
  evaluatingPolar--
  restore()