DigitAt: is a horrible name then, should rather be bitAt:.
the digitAt: implementation you're looking for:
^ self // (10 raisedTo: index - 1) \\ 10
thats quite short :)
On 2011-05-02, at 11:35, Bernat Romagosa wrote:
> Ouch, understood!
>
> Then what would be the proper way to address a decimal digit in a number? I
> can only think of (bigNumber asString at: index) asNumber, which is... awful.
>
> 2011/5/2 Sven Van Caekenberghe <[email protected]>
> Bernat,
>
> On 02 May 2011, at 11:13, Bernat Romagosa wrote:
>
> > Hi, try to run the following:
> >
> > (2 raisedTo: 100000) digitAt: 1
> >
> > The expected result (if I understood what digitAt: should return) is 9, but
> > the message returns 0 instead. In fact, it returns 0 for any index.
> >
> > Is this a bug or am I missunderstanding how digitAt: should work?
> >
> > Cheers,
> >
> > Bernat Romagosa.
> >
> > p.s. My config is Pharo 1.2 with a 'Croquet Closure Cog VM [CoInterpreter
> > VMMaker-oscog.51]' on Debian Lenny.
>
> Consider,
>
> 2 raisedTo: 32
>
> #digitAt: for digits 1 to 4 returns 0, 5 return 1.
> From the comments you can see that the number is looked at in base 256.
> The above number thus has 5 digits in this base, four are zero and the
> highest one is one.
> Furthermore, the first digit is the lowest one.
> If you inspect the number it might become clearer.
>
> Any #digitAt: has to depend on the base you use to represent the number, this
> one doesn't, so it seems to be useful only to return internal parts of a
> number.
>
> HTH,
>
> Sven
>
>
>
