[R] "--" < 0

[Adrian Dusa]

Oh I see...
It's not that "-7" gets coerced to numeric, but 0 gets coerced to "0".
Of course...

On Tue, Jun 25, 2024 at 11:02 AM Martin Maechler <maechler using stat.math.ethz.ch>
wrote:

> >>>>> Adrian Dusa
> >>>>>     on Tue, 25 Jun 2024 10:56:07 +0300 writes:
>
>     > Dear R fellows,
>
>     >> From time to time, just when I thought I knew my R, I get
>     >> bitten by some
>     > small things that reminds one to constantly return to the
>     > basics.
>
>     > I knew for instance that "-1" < 0 is TRUE, presumably
>     > because R first coerces to numeric before comparing with
>     > 0.
>
>     > But I did not expect that "--" < 0 is a TRUE statement.
>     > (and the same holds for any string prepended by a minus
>     > sign, e.g. "-a" < 0)
>
>     > I would be grateful for an explanation, I'm sure that
>     > something very obvious escapes me but it sure does seem
>     > counter intuitive to me.
>
>     > Best wishes, Adrian
>
>     >   [[alternative HTML version deleted]]
>
> Nice, quiz, yes.
>
> You must have forgotten that all Op's (+,-, <= , &, | ..)
> must coerce to common type.
>
> ... and so does  c()  where coercion is defined a bit more.
>
> -->  does  c("--", 0)   give you a clue, now ?
>

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