Eval_float = ->
  evaluatingAsFloats++
  push(cadr(p1))
  Eval()
  yyfloat()
  Eval(); # normalize
  evaluatingAsFloats--

checkFloatHasWorkedOutCompletely = (nodeToCheck) ->
  numberOfPowers = countOccurrencesOfSymbol(symbol(POWER),nodeToCheck)
  numberOfPIs = countOccurrencesOfSymbol(symbol(PI),nodeToCheck)
  numberOfEs = countOccurrencesOfSymbol(symbol(E),nodeToCheck)
  numberOfMults = countOccurrencesOfSymbol(symbol(MULTIPLY),nodeToCheck)
  numberOfSums = countOccurrencesOfSymbol(symbol(ADD),nodeToCheck)
  if DEBUG
    console.log "     ... numberOfPowers: " + numberOfPowers
    console.log "     ... numberOfPIs: " + numberOfPIs
    console.log "     ... numberOfEs: " + numberOfEs
    console.log "     ... numberOfMults: " + numberOfMults
    console.log "     ... numberOfSums: " + numberOfSums
  if numberOfPowers > 1 or numberOfPIs > 0 or numberOfEs > 0 or numberOfMults > 1 or numberOfSums > 1
    stop("float: some unevalued parts in " + nodeToCheck)

zzfloat = ->
  save()
  evaluatingAsFloats++
  #p1 = pop()
  #push(cadr(p1))
  #push(p1)
  Eval()
  yyfloat()
  Eval(); # normalize
  evaluatingAsFloats--
  restore()
  # zzfloat doesn't necessarily result in a double
  # , for example if there are variables. But
  # in many of the tests there should be indeed
  # a float, this line comes handy to highlight
  # when that doesn't happen for those tests.
  #checkFloatHasWorkedOutCompletely(stack[tos-1])

yyfloat = ->
  i = 0
  h = 0
  evaluatingAsFloats++
  save()
  p1 = pop()
  if (iscons(p1))
    h = tos
    while (iscons(p1))
      push(car(p1))
      yyfloat()
      p1 = cdr(p1)
    list(tos - h)
  else if (p1.k == TENSOR)
    push(p1)
    copy_tensor()
    p1 = pop()
    for i in [0...p1.tensor.nelem]
      push(p1.tensor.elem[i])
      yyfloat()
      p1.tensor.elem[i] = pop()
    push(p1)
  else if (p1.k == NUM)
    push(p1)
    bignum_float()
  else if (p1 == symbol(PI))
    push_double(Math.PI)
  else if (p1 == symbol(E))
    push_double(Math.E)
  else
    push(p1)
  restore()
  evaluatingAsFloats--