pws-19: comparing (k) and (I) for hashes

pws-19: comparing (k) and (I) for hashes

[Andrej Borsenkow]

>From manual I got the impression, that ${(k)...} and ${...[(I)...]} do the
same - both return the keys of matching elements. Cf. (I) description:

`I'
     like ``i', but gives the index of the last match, or all possible
     matching keys in an associative array.

In case of parameters hash, the keys are parameter names, so

bor@itsrm2:~%> print -l ${(k)parameters[(R)scalar*]} | grep foo
foo
bor@itsrm2:~%>

(as expected), but

bor@itsrm2:~%> print -l ${parameters[(I)scalar*]} | grep foo
bor@itsrm2:~%>

What do I do wrong?

/andrej

Re: pws-19: comparing (k) and (I) for hashes

[Peter Stephenson]

"Andrej Borsenkow" wrote:
> >From manual I got the impression, that ${(k)...} and ${...[(I)...]} do the
> same - both return the keys of matching elements. Cf. (I) description:
> 
> `I'
>      like ``i', but gives the index of the last match, or all possible
>      matching keys in an associative array.

Actually, I just specifies that it should search the keys (which correspond
to the index of an ordinary array).  k and v still determine what is
returned, except that for I and i the default is to show the key instead of
the value.

-- 
Peter Stephenson <pws@ibmth.df.unipi.it>       Tel: +39 050 844536
WWW:  http://www.ifh.de/~pws/
Dipartimento di Fisica, Via Buonarroti 2, 56127 Pisa, Italy