A method to not leak unneeded functions

A method to not leak unneeded functions

[Sebastian Gniazdowski]

Hello,
it's often the case when one declares sub-functions inside an autoload
function. The function will leak into the shell and also get redefined
on the next run of the main function. Here's a method to prevent this
from happening:

local -a entry_funs
entry_funs=( ${(k)functions} )
trap "unset -f \"\${(k)functions[@]:#(${(j:|:)${(q@)entry_funs}})}\"
&>/dev/null" EXIT
trap "unset -f \"\${(k)functions[@]:#(${(j:|:)${(q@)entry_funs}})}\"
&>/dev/null; return 1" INT

It will unset any newly detected functions at the moment of leaving of
the main function.
-- 
Sebastian Gniazdowski
News: https://twitter.com/ZdharmaI
IRC: https://kiwiirc.com/client/chat.freenode.net:+6697/#zplugin
Blog: http://zdharma.org

Re: A method to not leak unneeded functions

[Sebastian Gniazdowski]

PS. The block of code should be added at the beginning of the autoload
file, after possible emulate -L zsh, or at least after `setopt
localtraps' (which is being done by the emulate builtin). After this
the setup is complete and the functions will get automatically unset.

On Mon, 30 Sep 2019 at 00:22, Sebastian Gniazdowski
<sgniazdowski@gmail.com> wrote:
>
> Hello,
> it's often the case when one declares sub-functions inside an autoload
> function. The function will leak into the shell and also get redefined
> on the next run of the main function. Here's a method to prevent this
> from happening:
>
> local -a entry_funs
> entry_funs=( ${(k)functions} )
> trap "unset -f \"\${(k)functions[@]:#(${(j:|:)${(q@)entry_funs}})}\"
> &>/dev/null" EXIT
> trap "unset -f \"\${(k)functions[@]:#(${(j:|:)${(q@)entry_funs}})}\"
> &>/dev/null; return 1" INT
>
> It will unset any newly detected functions at the moment of leaving of
> the main function.
> --
> Sebastian Gniazdowski
> News: https://twitter.com/ZdharmaI
> IRC: https://kiwiirc.com/client/chat.freenode.net:+6697/#zplugin
> Blog: http://zdharma.org



-- 
Sebastian Gniazdowski
News: https://twitter.com/ZdharmaI
IRC: https://kiwiirc.com/client/chat.freenode.net:+6697/#zplugin
Blog: http://zdharma.org

Re: A method to not leak unneeded functions

[Sebastian Gniazdowski]

i've noticed one thing: the need of "--" passed to unset, to be able
to unset dash-starting functions. The snippet is thus:

local -a ef
ef=( ${(k)functions} )
trap "unset -f -- \"\${(k)functions[@]:#(${(j:|:)${(q@)ef}})}\"
&>/dev/null" EXIT
trap "unset -f -- \"\${(k)functions[@]:#(${(j:|:)${(q@)ef}})}\"
&>/dev/null; return 1" INT
unset ef

That said, I've also noticed that the method is somewhat slow. For
2700 functions, the trap takes 0.39 seconds. If it could use the $ef
parameter, then it could do $${(k)functions:|ef} which I measured to
take only 1 ms. However, at the time of the EXIT trap, the local
parameters are being unset.

Is there any way to speed this up?

-- 
Sebastian Gniazdowski
News: https://twitter.com/ZdharmaI
IRC: https://kiwiirc.com/client/chat.freenode.net:+6697/#zplugin
Blog: http://zdharma.org

Re: A method to not leak unneeded functions

[Sebastian Gniazdowski]

On Thu, 3 Oct 2019 at 23:18, Sebastian Gniazdowski
<sgniazdowski@gmail.com> wrote:
> Is there any way to speed this up?

Uhm, the solution is pretty obvious - to use a global ef-parameter. It
doesn't even need to be leaked outside the function - example snippet
for a `zpview' project:

typeset -g zpview_ef
zpview_ef=( ${(k)functions} )
trap "unset -f -- \"\${(k)functions[@]:|zpview_ef}\" &>/dev/null;
unset zpview_ef" EXIT
trap "unset -f -- \"\${(k)functions[@]:|zpview_ef}\" &>/dev/null;
unset zpview_ef; return 1" INT

As said, the method is fully instant, it takes only 1 ms to do the unset.
-- 
Sebastian Gniazdowski
News: https://twitter.com/ZdharmaI
IRC: https://kiwiirc.com/client/chat.freenode.net:+6697/#zplugin
Blog: http://zdharma.org