[BUG?] Accessing $userdirs (re)hashes all user dirs as named dirs

[BUG?] Accessing $userdirs (re)hashes all user dirs as named dirs

[Marlon Richert]

% zsh -f
% hash -dL
% : $userdirs
% hash -dL
[~120 dir names on macOS]

Almost none of these are dir names that I want or need. I don't think
this is desirable behavior. Is there a good reason for it to work this
way?

Re: [BUG?] Accessing $userdirs (re)hashes all user dirs as named dirs

[Bart Schaefer]

On Sun, Dec 5, 2021 at 1:35 AM Marlon Richert <marlon.richert@gmail.com> wrote:
>
> Almost none of these are dir names that I want or need. I don't think
> this is desirable behavior. Is there a good reason for it to work this
> way?

$userdirs is literally nothing more than an API on the named
directories hash table.

Re: [BUG?] Accessing $userdirs (re)hashes all user dirs as named dirs

[Marlon Richert]

 On Sun, Dec 5, 2021 at 7:45 PM Bart Schaefer <schaefer@brasslantern.com> wrote:
>
> On Sun, Dec 5, 2021 at 1:35 AM Marlon Richert <marlon.richert@gmail.com> wrote:
> >
> > Almost none of these are dir names that I want or need. I don't think
> > this is desirable behavior. Is there a good reason for it to work this
> > way?
>
> $userdirs is literally nothing more than an API on the named
> directories hash table.

OK, but before $userdirs has been accessed, `hash -dL` outputs nothing
but the dirs I hashed myself. Normally, after doing `cd ~username`
exactly one entry is added to hash -dL's output. However, after
$userdirs has been accessed (as, for example, happens, when the
completion function _users has been called), the output is now
populated with ~120 usernames I don't want or need.

The same happens if I `hash -df`. Why would "rebuilding" this hash
table result in entries that weren't there in the first place? What is
the reasoning behind this?

Re: [BUG?] Accessing $userdirs (re)hashes all user dirs as named dirs

[Bart Schaefer]

On Sun, Dec 5, 2021 at 11:40 AM Marlon Richert <marlon.richert@gmail.com> wrote:
>
> Why would "rebuilding" this hash
> table result in entries that weren't there in the first place? What is
> the reasoning behind this?

The C-code interface for associative array variables (of which
$userdirs is a special case) requires that you are able to iterate
over all the keys of the array.  The keys in this case consist of all
possible user (home directory) names, so the hash table has to be
fully populated.