Re: No expansions performed while declaring an associative array using a list of keys and values

[Chet Ramey]

On 12/11/20 7:08 AM, Oğuz wrote:
> I was trying the new features of bash 5.1 and came across this inconsistent
> behavior:
>
>      $ foo='1 2'
>      $ declare -A bar=($foo 3)
>      $ declare -p bar
>      declare -A bar=(["\$foo"]="3" )
>      $
>      $ bar+=($foo 3)
>      $ declare -p bar
>      declare -A bar=(["\$foo"]="3" ["1 2"]="3" )
>
> Is there a particular reason to avoid performing expansions in `declare -A
> bar=($foo 3)'?

The idea is that each word in the list undergoes the same expansion as the
keys and values in a [$key]=value word in the compound assignments. Right
now, the implementation is pretty simple. For instance, if you use
something like

set -- a b c d e f g
declare -A v
v=( "$@" )

you'll get an associative array with a single key 'a b c d e f g' and a
null value.

I agree that it would be useful to have

foo='1 2'
declare -A v1=$( $foo 3 )
declare -A v2=$( [$foo]=3 )

set the two arrays to the same contents, so I'll see what needs to change
to do that.

Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/