Re: triviality regarding $# counts

["Mark J. Reed" <markjreed@gmail.com>]

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>
> # It's not a zebra, it's a horse with painted stripes!
> # If you want a COPY ... yes, a Xerox copy:
> % fff=( "${(@f)ddd}" )


What? No.  Why do you keep bringing (f) into this? That flag has nothing to
do with copying; in fact it intentionally changes things: anywhere there
used to be a single string containing a newline,you get two strings
instead.

But if you drop the f, you do get your Xerox copy:

% fff=( "${(@)ddd}" )

Would it be nicer if you could just do *fff=$ddd* and not have to include
the parens and quotes and @? Sure. You could even make a case that it *should
*work that way, since we're in Zshland where *$ddd* expands to the whole
array instead of a single element. But that's not the way assignment works.
Though, as I said, if the array has no empty elements, you can get away
with just *fff=($ddd)*.






On Sun, Apr 14, 2024 at 9:24 AM Ray Andrews <rayandrews@eastlink.ca> wrote:

>
>
> On 2024-04-13 21:57, Bart Schaefer wrote:
>
> Because zsh does not split parameter expansions by default, $ary and
> $ary[*] and $ary[@] are equivalent when not quoted, as Lawrence
> demonstrated.
>
> However, in all three of those cases, empty elements are typically
> discarded, as they would be in a shell that defaults to splitting.
> That's why "$ary[@]" is still useful:  It quotes each element
> individually, so empty elements are preserved.
>
> (Aside, in bash and ksh, $ary is equivalent to ${ary[0]}, not to
> ${ary[*]}.  A little oddly, this is also true for their associative
> arrays, that is, the value for key 0 is used.)
>
> I know it's far too late to fret this stuff, still it's interesting to
> contemplate these design level issues.  P.F. did the right thing not
> splitting by default but he should have left the empties in by default too,
> IMHO.  Options should be positive not negative as a fundamental principle.
> Don't do helpful things automatically, and force me to stop you from doing
> them.  Much better to leave things alone, and if I want, say, empty
> elements removed, I'll ask for them to be removed.  A=B should mean that A
> is identical to B, not B with blanks removed, nor sorted, nor capitalized,
> nor duplicates removed, nor checked for spelling, nor ... nothing.
>
> "$ary[@]" should be the default with some ${(?)...} flag to indicate that
> I'd like blanks removed or  duplicates or ... whatever massaging I'd want.
> Cool that all those manipulations are available of course, but as Raymond
> Sensei  (E. S. Raymond) explains so well, the 'doctrine of least surprise'
> should prevail.  Equals equals equals, not 'equals minus blanks'.  So we
> have:
>
> aaa=( "${(@f)bbb}" )
>
> ... which is code fighting itself.  The quotes normally mean 'join
> together' but they also mean 'preserve spaces' and so then '(@f)'
> contradicts the joining so we retain multiple elements.  IMHO it should
> look like this:
>
> aaa=( $bbb )
>
> Equals equals equals.
>
> But as we have  it:
>
>
> ----------------------------------------------------------------------------------
>
> % print $ddd
> abc     def ghi     jkl mno     pqr
>
> % fff=( $ddd )
>
> % print $fff
> abc     def ghi     jkl mno     pqr
>
> # Looks ok, donit? But don't be a chump:
>
> % typeset -p ddd; typeset -p fff
> typeset -a ddd=( '' abc '' $'\tdef ghi' $'\tjkl mno' '' $'\tpqr' '' )
> typeset -a fff=( abc $'\tdef ghi' $'\tjkl mno' $'\tpqr' )
>
> # It's not a zebra, it's a horse with painted stripes!
> # If you want a COPY ... yes, a Xerox copy:
>
> % fff=( "${(@f)ddd}" )
>
> % typeset -p ddd; typeset -p fff
> typeset -a ddd=( '' abc '' $'\tdef ghi' $'\tjkl mno' '' $'\tpqr' '' )
> typeset -a fff=( '' abc '' $'\tdef ghi' $'\tjkl mno' '' $'\tpqr' '' )
>
> # That's a COPY ... and don't even think about a simpler way, we are on
> this earth to suffer.
>
>
> ------------------------------------------------------------------------------------
>
> Just sayin', I know there's nothing to be done about it now.
>
>
>
>

-- 
Mark J. Reed <markjreed@gmail.com>

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