Error in Simple_Numbers library object

Phil Pilgrim (PhiPi)

Here's the program:

CON

  _clkmode      = xtal1 + pll16x
  _xinfreq      = 5_000_000

OBJ

  pst   : "Parallax Serial Terminal"
  num   : "Simple_Numbers"

PUB  start | seed, value, best, worst, sum, n

  pst.start(9600)
  pst.str(num.decx(1_580_219_585, 10))

Here's what gets output:

0170154177

-Phil

Duane Degn

You probably already know this but it looks like this line is the culprit.

  value //= (div * 10)                                  ' truncate unused digits
  

"div * 10" in this case is over 32 bits.

Phil Pilgrim (PhiPi)

Duane,

Thanks. I hadn't bothered yet to find the cause, but I'm sure you're right.

-Phil

Duane Degn

I modified method I use a lot to return a string address instead of having the string as an argument in the call.

I think most of it originated in Tim Moore's four port serial object.

The number displays correctly with this modified method (there are actually two different methods used).

PUB Decx(value, digits)  
'' Prints zero-padded, signed-decimal string
'' -- if value is negative, field width is digits+1
  result := decl(value, digits, 2)
PUB Decl(value, digits, flag) | localI, localX, localPtr
'' DWD Fixed with FDX 1.2 code
  digits := 1 #> digits <# 10
  localPtr := @nstr  
  localX := value == NEGX       'Check for max negative
  if value < 0
    value := ||(value + localX) 'If negative, make positive; adjust for max negative
    byte[localPtr++] := "-"
  localI := 1_000_000_000
  if flag & 3
    if digits < 10                                      ' less than 10 digits?
      repeat (10 - digits)                              '   yes, adjust divisor
        localI /= 10
  repeat digits
    if value => localI
      byte[localPtr++] := value / localI + "0" + localX * (localI == 1)
      value //= localI
      result~~
    elseif (localI == 1) OR result OR (flag & 2)
      byte[localPtr++] := "0"
    elseif flag & 1
      byte[localPtr++] := " "
    localI /= 10
  result := @nstr
    

It should be cleaned up before being added to Simple_Numbers officially.

Again, most of it is not my code.

Phil Pilgrim (PhiPi)

Frankly, I've never liked the way Simple_Numbers handles fixed-length fields when it comes to negative numbers. To make the columns line up correctly, the minus sign should be included in the digit count. IMO, anything short of that is just plain lazy programming.

-Phil