Re: integer or float?

You missed the point. No pun intended.

The numeric value of "1." is distinct from the value "1", not just in zsh
but many proglangs. "1." is a float where "1" is an int. Which means if you
divide "1."  by 2, you get 0.5. But if you divide "1" by 2, you get 0.

So that period is conveying type information. A trailing 0 would also,work
though it suggests a level of precision that may not be appropriate. But
printing the float value 1. as "1" would destroy the ability to capture
that value intact and recreate it from the output string - which is of
course the only way you can "return" such a value in a shell script.

Mark J. Reed <[email protected]>


On Thu, Oct 2, 2025 at 09:10 Ray Andrews <[email protected]> wrote:

>
>
> On 2025-10-01 21:31, Lawrence Velázquez wrote:
> >       % x=$((1.0))
> >       % typeset -p x
> >       typeset x=1.
> >       % print $((x / 2))
> >       0.5
> >
> > you would get this:
> >
> >       % x=$((1.0))
> >       % typeset -p x
> >       typeset x=1
> >       % print $((x / 2))
> >       0
> >
> >
> Ah, but that is an actual decimal value which of course must be
> preserved.  BTW I note the mathematically conventional *leading* zero.
> By exactly the same convention a trailing zero is correct: '5.0',
> '0.5'.  '5.'  is as mathematically dirty as '.5'  (with no leading zero)
> would be.  Anyway I take it that this is now so deeply established that
> it would be unwise to tinker with it given that there's no real problem
> once you understand what's going on. However the above:
>
> % unsetopt FORCE_FLOAT
>         % echo $((1.0))
>         1.
>
> ... really does seem like a mistake:
>
> % setopt forcefloat; echo $((1.0))
> 1.
>
> % unsetopt forcefloat; echo $((1.0))
> 1.
>
> % unsetopt forcefloat; echo $((1))
> 1
>
> % setopt forcefloat; echo $((1))
> 1.
>
> contrast the uniform an correct output here:
>
> % setopt forcefloat; echo $((.5))
> 0.5
>
> % unsetopt forcefloat; echo $((.5))
> 0.5
>
> % setopt forcefloat; echo $((0.5))
> 0.5
>
> % unsetopt forcefloat; echo $((0.5))
> 0.5
>
> ... note that above zsh actually 'fixes it for you': '.5' becomes
> '0.5'.  So we have rigor with leading zeros but not trailing zeros.
>
> BTW another question:
>
> Playing with Benford's Law, I had zsh creating my data for me, say 1000
> random floats, then each of them multiplied by another random float and
> the whole thing repeated some number of iterations.  Then graph it in
> GeoGebra.  Anyway I finally got the math done within GeoGebra (vastly
> more obtuse than zsh!) and it will recompute the whole show in less than
> a second whereas the same data from zsh took about a minute -- and
> that's just the data, not including graphing. Now, zsh is not
> graphing/mathematical software so I'm not whining, still I'm curious,
> I'd expect that under the hood a math call is a math call at the system
> level.  I'm guessing that it's because zsh is interpreted whereas GG can
> probably ... I'll say 'compile' for lack of a better word.  Yes?
>
> https://www.geogebra.org/m/aeafk6bs
>
>
>