Associative Arrays don't work

Associative Arrays don't work

[Com MN PG P E B Consultant 3]

zsh is supposed to have associative arrays, but they don't work for me.
Here an example:

$ zz=()       # According to zsh doc, should created any array,
including associative 
$ zz[f]=4     # Set element f to 4
$ echo $zz[g] # Request element g (not f). Element g should not be
there, but we get 4
4
$ zz[g]=5     # Set element g to 5
$ echo $zz[f] # Request element f. We should get 4, but we get 5
5

Hence, "f" and "g" are treated equivalent - not what I would expect from
an associative array.

I googled a bit in the zsh mailing list archive and found a posting from
1998 which claimed
that one should use the -H option to create an associative array. Though
this seems to contradict
the documentation for zsh, I tried the example posted there - and the
result was even more 
bizarre:

$ typeset -H assoc
$ assoc[bread]=butter
$ assoc[toast]=jam
$ echo $assoc
jamutter
$ echo $assoc[bread]
j

I tried these examples with the two zsh versions I have access to -
4.0.7 and 4.2.4 - and got
the same result on both.

Ronald
-- 
Ronald Fischer (phone +49-89-63676431)
mailto:mn-pg-p-e-b-consultant-3.com@siemens.com

Re: Associative Arrays don't work

[DervishD]

    Hi Ronald :)

 * Com MN PG P E B Consultant 3 <mn-pg-p-e-b-consultant-3.com@siemens.com> dixit:
> $ zz=()       # According to zsh doc, should created any array, including associative 

    I can't find where is that said. On the contrary, what I've found
is this:

    "Associative arrays _must_ be declared before assignment..."

> $ zz[f]=4     # Set element f to 4
> $ echo $zz[g] # Request element g (not f). Element g should not be there, but we get 4

    Of course, "g" is zero, so you get the zeroth element from the
array you just vivified.

> $ zz[g]=5     # Set element g to 5
> $ echo $zz[f] # Request element f. We should get 4, but we get 5

    Idem. You assigned to element zero, so you modified it.

    Try this:

    $ typeset -A zz
    $ zz[f]=4
    $ zz[g]=5
    $ print "Here goes zz[f] =>$zz[f] and here zz[g] =>$zz[g]"
    Here goes zz[f] =>4 and here zz[g] =>5

    Hope this helps ;) (tested under 4.2.6, BTW)

    Raúl Núñez de Arenas Coronado

-- 
Linux Registered User 88736 | http://www.dervishd.net
http://www.pleyades.net & http://www.gotesdelluna.net
It's my PC and I'll cry if I want to... RAmen!

Re: Associative Arrays don't work

[DervishD]

    Hi Ronald :)

 * Com MN PG P E B Consultant 3 <mn-pg-p-e-b-consultant-3.com@siemens.com> dixit:
[Contradictory documentation]
> >     I can't find where is that said. 
> 
> Having reread http://zsh.sunsite.dk/Doc/Release/zsh_14.html#SEC72
> again, I now see that we have two contradicting statements about
> this. The first one is exactly like you said:
> > 
> >     "Associative arrays _must_ be declared before assignment..."
> 
> The second information, further down this section, says:
> 
> "To create an empty array (including associative arrays), use one of: 
>    set -A name 
>    name=()"
> 
> When I saw the "use one of", I was happy enough to not read the whole
> section verbatim.

    What I would have understood from the above is that name=() will
work for both kind of arrays, you're right... I missed that part
(probably because I already know that the "set -A name" is needed).
The docs may be more clear at that point.

> >     Hope this helps ;) (tested under 4.2.6, BTW)
> 
> It does, indeed. Thank you very much!

    You're very welcome ;)

    Raúl Núñez de Arenas Coronado

-- 
Linux Registered User 88736 | http://www.dervishd.net
http://www.pleyades.net & http://www.gotesdelluna.net
It's my PC and I'll cry if I want to... RAmen!

RE: Associative Arrays don't work

[Com MN PG P E B Consultant 3]

>  * Com MN PG P E B Consultant 3 
> <mn-pg-p-e-b-consultant-3.com@siemens.com> dixit:
> > $ zz=()       # According to zsh doc, should created any 
> array, including associative 
> 
>     I can't find where is that said. 

Having reread http://zsh.sunsite.dk/Doc/Release/zsh_14.html#SEC72 again,
I now see
that we have two contradicting statements about this. The first one is
exactly
like you said:

> 
On the contrary, what I've found
> is this:
> 
>     "Associative arrays _must_ be declared before assignment..."

The second information, further down this section, says:

"To create an empty array (including associative arrays), use one of: 
   set -A name 
   name=()"

When I saw the "use one of", I was happy enough to not read the whole
section verbatim.
Hence, I had chosen the "name=()" form, believing that it would be
sufficient. 

I now see that I has mistakingly believed that creation of an
associative array could
be done without declaring it.

>     Try this:
> 
>     $ typeset -A zz
>     $ zz[f]=4
>     $ zz[g]=5
>     $ print "Here goes zz[f] =>$zz[f] and here zz[g] =>$zz[g]"
>     Here goes zz[f] =>4 and here zz[g] =>5
> 
>     Hope this helps ;) (tested under 4.2.6, BTW)

It does, indeed. Thank you very much!

Ronald
-- 
Ronald Fischer (phone +49-89-63676431)
mailto:mn-pg-p-e-b-consultant-3.com@siemens.com