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

[Pascal Maugis]

Thank both of you. It's an issue I was totally anaware of :) But now 
that you tell it, seems logical.

Take care,

Pascal.

Le 13/09/2022 à 15:07, arnold@skeeve.com a écrit :
> 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.
> > --
> > ------------------------------------------------------------------------
> >
> > *Pascal MAUGIS*
> > Modélisation hydrologique et changement climatique, PhD
> >
> > LSCE
> >
> > Laboratoire des Sciences du Climat et de l'Environnement
> > <http://www.lsce.ipsl.fr/>
> >
> > Unité Mixte de Recherche CEA-CNRS-UVSQ (UMR 8212), IPSL, Paris-Saclay
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> > Bât. 714, pièce 2115
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> >
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> > Page perso : FR<http://www.lsce.ipsl.fr/Pisp/pascal.maugis/>  - EN
> > <http://www.lsce.ipsl.fr/en/Phocea/Pisp/index.php?nom=pascal.maugis>
> > Tel./Fax : +33 1 69 08 75 24 / +33 1 69 08 77 16
> >
> > ------------------------------------------------------------------------
--
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*Pascal MAUGIS*
Modélisation hydrologique et changement climatique, PhD

LSCE

Laboratoire des Sciences du Climat et de l'Environnement 
<http://www.lsce.ipsl.fr/>

Unité Mixte de Recherche CEA-CNRS-UVSQ (UMR 8212), IPSL, Paris-Saclay
Equipe MOSAIC : MOdelisation des SurfAces et Interfaces Continentales
Bât. 714, pièce 2115
C.E. Saclay, Orme des Merisiers, 91191 Gif-sur-Yvette Cedex, FRANCE

e-mail : pascal.maugis@lsce.ipsl.fr
Page perso : FR <http://www.lsce.ipsl.fr/Pisp/pascal.maugis/> - EN 
<http://www.lsce.ipsl.fr/en/Phocea/Pisp/index.php?nom=pascal.maugis>
Tel./Fax : +33 1 69 08 75 24 / +33 1 69 08 77 16

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