(49G) Z->B & B->Z full Accuracy

[Gerald H]

The 49G converts zints to hexadecimal strings by R->B, first transforming the zint to a real & thereby loosing significant digits.

This programme does Z->B & B->Z to full accuracy.

eg For input

9898989898989898979

the programme returns

# 9898989898989898979d

& applying the programme again returns the original zint.

Code:

::
  CK1&Dispatch
  # FF
  ::
    BINT64
    dostws
    FPTR2 ^DupZIsNeg?
    casedrop
    HXS 00001 0
    ZINT 18446744073709551615
    FPTR2 ^ZNMin
    DUP
    FPTR2 ^Z>R
    %>#
    DUP
    HXS>%
    FPTR2 ^R>Z
    ROT
    FPTR2 ^RSUBext
    FPTR2 ^Z>R
    % 100000000.
    DUPUNROT
    %+SWAP
    %>#
    bit%#-
    bit-
  ;
  BINT11
  ::
    BINT64
    dostws
    DUP
    HXS>%
    DUP
    FPTR2 ^R>Z
    SWAPROT
    bit%#-
    % 100000000.
    DUPUNROT
    %>#
    bit+
    HXS>%
    SWAP
    %-
    FPTR2 ^R>Z
    FPTR2 ^RSUBext
  ;
;