[R] "--" < 0

[Martin Maechler]

>>>>> 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 ?