Re: attribution of ++ to the wrong variable in "a ++b"

[arnold]

Awk doesn't care (much) about spaces because of string concatenation:

        a = "hello "
        b = "world"
        print a b

Arnold

Pascal Maugis <pascal.maugis@lsce.ipsl.fr> wrote:

> Thanks Ed,
>
> I didn't know that awk cared little for spaces as separators. I will 
> switch to parenthesis, then.
>
> May I suggest this aspect be stressed somewhere in the documentation, 
> maybe after §1.6, or §6.2 Operators: Doing Something with Values, or 
> specifically for ++ in §6.2.4. ?
>
> Cheers,
>
> Pascal.
>
> Le 13/09/2022 à 13:40, Ed Morton a écrit :
> > On 9/13/2022 5:42 AM, Pascal Maugis wrote:
> >> Hi, as promised here is the strange, unexpected behavior of ++ that 
> >> looks like an error to me, because in "a ++b", a is incremented 
> >> instead of b. "a b++" and "a++ b" produce the correct results however :
> >>
> >>    touch a.awk
> >>    gawk -D -f ./a.awk
> >>    eval "a=1 ; b=2"
> >>    eval "print a ++b"   ; output = 12 : (variables will be incremented
> >>    after the operation, ok with me as documented)
> >>    eval "print a b"     ; output = 22 : a has been incremented 
> >> instead of b
> >>    eval "print a++b"    ; output = 22 :
> >>    eval "print a b"     ; output = 32 : a has been incremented
> >>
> >> The operation seems to be interpreted as "a++b", the space been 
> >> uninterpreted as a separator
> >>
> > Pascal - with a few exceptions, white space generally doesn't matter 
> > to awk. If you want to ensure that `a ++b` gets interpreted as `a 
> > (++b)` then that latter is the code you need to write since once you 
> > remove/ignore white space `a++ b` and `a ++b` are both `a++b` which 
> > visually could be interpreted either way.
> >
> >     Ed.
> -- 
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> *Pascal MAUGIS*
> Modélisation hydrologique et changement climatique, PhD
>
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