Re: with-eval-after-load with sh-mode

[Arthur Miller <arthur.miller@live.com>]

lisa-asket@perso.be writes:

>>From: Arthur Miller <arthur.miller@live.com>
>>To: lisa-asket@perso.be
>>Subject: Re: with-eval-after-load with sh-mode
>>Date: 02/07/2021 10:56:14 Europe/Paris
>>Cc: help-gnu-emacs@gnu.org
>
>>lisa-asket@perso.be writes:
>
>>>From: Arthur Miller <arthur.miller@live.com>
>>>To: lisa-asket@perso.be
>>>Subject: Re: with-eval-after-load with sh-mode
>>>Date: 02/07/2021 10:42:38 Europe/Paris
>>>Cc: help-gnu-emacs@gnu.org
>>
>>>lisa-asket@perso.be writes:
>>
>>>> How can I use `with-eval-after-load` with sh-mode?
>>>>
>>>> Basically I want to defer call to sh-mode-map until sh-mode is loaded
>>>>
>>>> (with-eval-after-load 'sh
>>
>>>Try this:
>>
>>>(with-eval-after-load 'sh-script
>>>(message "My cool one-time config follows here ..."))
>>
>>>sh-mode is defined in lisp/progmodes/sh-script.el.
>>
>> What is the difference between 
>>
>> (with-eval-after-load 'sh-script
>> (myfun))
>>
>> and
>>
>> (add-hook 'sh-mode-hook #'myfun)
>
>>Obviously sh-mode-hook gets executed every time you load sh-mode, i.e,
>>when you open a shell file.
>
>>eval after load will kick in when feature is loaded, i.e. when you read
>>in (load or require) sh-script.el, so it least in theory it should get
>>executed only once, unless you unload feature 'sh-script for some reason.
>
> This leads to another consideraion.  There are certainly advantages about using
> `with-eval-after-load`.  But, then, what are the circumstances for using `add-hook`?

As said above: the circustance is when you wish a piece of code to run
every time a mode is loaded.

You should probably read the fine manual:

https://www.gnu.org/software/emacs/manual/html_node/emacs/Hooks.html
https://www.gnu.org/software/emacs/manual/html_node/elisp/Hooks-for-Loading.html