5.3.1-dev-0 difference in array=( "${(PA@)var_name}" )

5.3.1-dev-0 difference in array=( "${(PA@)var_name}" )

[Sebastian Gniazdowski]

Hello,
% zsh-5.3.1
% var_name="abcdef"; array=( "${(PA@)var_name}" ); echo ${#array}
1

% zsh-5.3.1-dev-0
% var_name="abcdef"; array=( "${(PA@)var_name}" ); echo ${#array}
0

I am busy with valgrind test tool so I barely can bisect, can do this tomorrow if no resolution

--
Sebastian Gniazdowski
psprint /at/ zdharma.org

Re: 5.3.1-dev-0 difference in array=( "${(PA@)var_name}" )

[Bart Schaefer]

On Wed, Jun 14, 2017 at 10:09 AM, Sebastian Gniazdowski
<psprint@zdharma.org> wrote:
> Hello,
> % zsh-5.3.1
> % var_name="abcdef"; array=( "${(PA@)var_name}" ); echo ${#array}
> 1

The (A) flag doesn't mean anything in this context in 5.3.1, that was
added about 2 months after the 5.3.1 release.

So in the above example ${(P)var_name} returns a scalar and the (@)
flag is also meaningless.  In this next example --

> % zsh-5.3.1-dev-0
> % var_name="abcdef"; array=( "${(PA@)var_name}" ); echo ${#array}
> 0

-- the (A) flag does apply , so ${(PA)var_name} is an empty array
rather than an unset scalar, and (@) causes the double-quotes to
resolve to nothing rather than to a quoted empty string, just as
"${emptyarray[@]}" would do.

Re: 5.3.1-dev-0 difference in array=( "${(PA@)var_name}" )

[Sebastian Gniazdowski]

On 14-06-2017 at 22:35:51, Bart Schaefer (schaefer@brasslantern.com) wrote:
> On Wed, Jun 14, 2017 at 10:09 AM, Sebastian Gniazdowski
> wrote:
> > Hello,
> > % zsh-5.3.1
> > % var_name="abcdef"; array=( "${(PA@)var_name}" ); echo ${#array}
> > 1
> 
> The (A) flag doesn't mean anything in this context in 5.3.1, that was
> added about 2 months after the 5.3.1 release.

I suspect it was this patch about using A outside ::= context.

> So in the above example ${(P)var_name} returns a scalar and the (@)
> flag is also meaningless. In this next example --

I think @ has an actual effect:

> zsh-5.1.1
> abcdef=( a b ); var_name="abcdef"; array=( "${(PA@)var_name}" ); echo ${#array}
2
> ... array=( "${(P@)var_name}" ); echo ${#array}
2
> ... array=( "${(PA)var_name}" ); echo ${#array}
1
> ... array=( "${(P)var_name}" ); echo ${#array}
1

> resolve to nothing rather than to a quoted empty string, just as
> "${emptyarray[@]}" would do.

Yes it's a change for the better.

--
Sebastian Gniazdowski
psprint /at/ zdharma.org

Re: 5.3.1-dev-0 difference in array=( "${(PA@)var_name}" )

[Bart Schaefer]

On Wed, Jun 14, 2017 at 11:03 PM, Sebastian Gniazdowski
<psprint@zdharma.org> wrote:
> On 14-06-2017 at 22:35:51, Bart Schaefer (schaefer@brasslantern.com) wrote:
>>
>> So in the above example ${(P)var_name} returns a scalar and the (@)
>> flag is also meaningless. In this next example --
>
> I think @ has an actual effect:

Well, yes, it has an effect if $abcdef is already an array (as in your
new example).  It has no effect if $abcdef is unset (as in your
original example) or is a scalar.