Re: PATCH: Invoke prompt cleanup hooks when changing prompt

[Arseny Maslennikov <ar@cs.msu.ru>]

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On Tue, Jul 07, 2020 at 01:50:04PM +0200, Roman Perepelitsa wrote:
> The documentation for promptinit states that themes can install
> cleanup hooks via prompt_cleanup.
> 
> > If your function makes any other changes that should
> > be undone when the theme is disabled, your setup function
> > may call
> >
> >     prompt_cleanup command
> >
> > where command should be suitably quoted. If your theme
> > is ever disabled or replaced by another, command is
> > executed with eval.
> 
> The documentation also states that:
> 
> > The precmd and preexec hooks are automatically
> > adjusted if the prompt theme changes or is disabled.

I understood that in terms of workers/30087: the theme "foo" may define
prompt_foo_precmd and prompt_foo_preexec, which are removed from the
respective arrays if the prompt theme is deactivated.

It would probably make sense to do something like

(( $+functions[prompt_$name_precmd] )) &&
    [[ -n ${precmd_functions[(r)prompt_$name_precmd]} ]] &&
    precmd_functions+=(prompt_$name_precmd)

automatically on theme activation, though — to match the above.

> 
> If I understand it correctly, this implies that the following script
> should print "cleanup" and shouldn't print "hook".
> 
>   autoload -Uz promptinit
>   promptinit
>   prompt_foo_setup() {
>     prompt_cleanup 'print cleanup'
>     precmd_functions+=(hook)
>   }
>   prompt_themes+=(foo)
>   prompt foo

Consider the following right here:

    precmd_functions+=(func1 func2)
>   prompt off
>   print -r -- $precmd_functions
> 
> It doesn't print "cleanup" and does print "hook".

As per what you suggest, user-supplied precmd functions, which
were set after prompt theme activation — in that example func1 and
func2 — will be unhooked as well. I doubt this is what users want.

> 
> I'm attaching a patch that does what I believe the documentation
> describes. I'm not very confident that I understood the documentation
> or that my patch is correct.
> 
> Roman.

> diff --git a/Functions/Prompts/promptinit b/Functions/Prompts/promptinit
> index e27b8779a..a9850d35c 100644
> --- a/Functions/Prompts/promptinit
> +++ b/Functions/Prompts/promptinit
> @@ -200,33 +200,37 @@ prompt_cleanup () {
>  prompt () {
>    local -a prompt_opts theme_active
>  
> -  zstyle -g theme_active :prompt-theme cleanup || {
> -    # This is done here rather than in set_prompt so that it
> -    # is safe and sane for set_prompt to setopt localoptions,
> -    # which will be cleared before we arrive back here again.
> -    # This is also why we pass around the prompt_opts array.
> -    [[ -o promptbang ]] && prompt_opts+=(bang)
> -    [[ -o promptcr ]] && prompt_opts+=(cr)
> -    [[ -o promptpercent ]] && prompt_opts+=(percent)
> -    [[ -o promptsp ]] && prompt_opts+=(sp)
> -    [[ -o promptsubst ]] && prompt_opts+=(subst)
> -    zstyle -e :prompt-theme cleanup \
> -        'zstyle -d :prompt-theme cleanup;' \
> -	'prompt_default_setup;' \
> -        ${PS1+PS1="${(q)PS1}"} \
> -        ${PS2+PS2="${(q)PS2}"} \
> -        ${PS3+PS3="${(q)PS3}"} \
> -        ${PS4+PS4="${(q)PS4}"} \
> -        ${RPS1+RPS1="${(q)RPS1}"} \
> -        ${RPS2+RPS2="${(q)RPS2}"} \
> -        ${RPROMPT+RPROMPT="${(q)RPROMPT}"} \
> -        ${RPROMPT2+RPROMPT2="${(q)RPROMPT2}"} \
> -        ${PSVAR+PSVAR="${(q)PSVAR}"} \
> -        "precmd_functions=(${(q)precmd_functions[@]})" \
> -        "preexec_functions=(${(q)preexec_functions[@]})" \
> -        "prompt_opts=( ${prompt_opts[*]} )" \
> -        'reply=(yes)'
> +  zstyle -g theme_active :prompt-theme cleanup && {
> +    local -a reply
> +    eval "$theme_active"

Nit: `prompt restore' opts to call `zstyle -t :prompt-theme cleanup' to
do this.

>    }
> +
> +  # This is done here rather than in set_prompt so that it
> +  # is safe and sane for set_prompt to setopt localoptions,
> +  # which will be cleared before we arrive back here again.
> +  # This is also why we pass around the prompt_opts array.
> +  [[ -o promptbang ]] && prompt_opts+=(bang)
> +  [[ -o promptcr ]] && prompt_opts+=(cr)
> +  [[ -o promptpercent ]] && prompt_opts+=(percent)
> +  [[ -o promptsp ]] && prompt_opts+=(sp)
> +  [[ -o promptsubst ]] && prompt_opts+=(subst)
> +  zstyle -e :prompt-theme cleanup \
> +      'zstyle -d :prompt-theme cleanup;' \
> +      'prompt_default_setup;' \
> +      ${PS1+PS1="${(q)PS1}"} \
> +      ${PS2+PS2="${(q)PS2}"} \
> +      ${PS3+PS3="${(q)PS3}"} \
> +      ${PS4+PS4="${(q)PS4}"} \
> +      ${RPS1+RPS1="${(q)RPS1}"} \
> +      ${RPS2+RPS2="${(q)RPS2}"} \
> +      ${RPROMPT+RPROMPT="${(q)RPROMPT}"} \
> +      ${RPROMPT2+RPROMPT2="${(q)RPROMPT2}"} \
> +      ${PSVAR+PSVAR="${(q)PSVAR}"} \
> +      "precmd_functions=(${(q)precmd_functions[@]})" \
> +      "preexec_functions=(${(q)preexec_functions[@]})" \
> +      "prompt_opts=( ${prompt_opts[*]} )" \
> +      'reply=(yes)'
> +
>    set_prompt "$@"
>  
>    (( ${#prompt_opts} )) &&


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