FYI, since I'm reporting behavior of 4.2 and this appears fixed in 4.4.
In 4.2, it seems that providing the =() as part of the declaration throws away
the -g-ness of the declaration-within-a-function. I need to touch it after the
declare:
(10:29)condor:~[518,18]$ bash -c 'function foo() { declare -g -A bar;
bar[baz]=quux; }; foo; echo ${#bar[@]}'
1
(10:29)condor:~[519,19]$ bash -c 'function foo() { declare -g -A bar=();
bar[baz]=quux; }; foo; echo ${#bar[@]}'
0
(10:29)condor:~[520,20]$ bash -c 'function foo() { declare -g -A bar; bar=();
bar[baz]=quux; }; foo; echo ${#bar[@]}'
1
-----Original Message-----
From: David Linden
Sent: Thursday, November 7, 2024 12:42 AM
To: Greg Wooledge <g...@wooledge.org>
Cc: bug-bash@gnu.org
Subject: RE: [EXTERNAL] - Re: This errors in 4.4, did not in 4.2: set -u;
declare -A foo; echo ${#foo[@]}
Thanks, and for the quick reply.
Language lawyers...
I'm curious what motivated the change. Naively it seems creating a placeholder
for a potential future array keeping track of attributes is more work than just
creating an empty array. The change is "surprising" to a user, at least this
user.
-----Original Message-----
From: Greg Wooledge <g...@wooledge.org>
Sent: Wednesday, November 6, 2024 10:26 PM
To: David Linden <dlin...@opentext.com>
Cc: bug-bash@gnu.org
Subject: [EXTERNAL] - Re: This errors in 4.4, did not in 4.2: set -u; declare
-A foo; echo ${#foo[@]}
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On Thu, Nov 07, 2024 at 02:38:05 +0000, David Linden wrote:
> Description:
> This errors in 4.4, did not in 4.2: set -u; declare -A foo; echo
> ${#foo[@]}
> How am I supposed to determine that a declared associative array is
> empty?
The easiest way would be to ensure that the array variable is actually
created:
set -u; declare -A foo=(); echo "${#foo[@]}"
Without the =() part, declare -A only creates a placeholder, which will assign
the -A flag to a future variable named foo, if one is ever created.
You need an assignment to create the variable.
