help-gnu-emacs
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Adding and running a major mode hook


From: Jacob Gerlach
Subject: Re: Adding and running a major mode hook
Date: Sun, 27 Apr 2014 04:56:46 -0700 (PDT)
User-agent: G2/1.0

> If you've got the run-hooks inside the mode declaration, then the hooks
> 
> won't run until the user activates the mode in some particular buffer.
> 
> They will then run *every* time your mode is activated.
> 
> 
> 
> If you've got it at the top level of the file, the hooks will run once,
> 
> *while* the file is being loaded for the first time: ie quite likely
> 
> during emacs startup, possibly before the user's relevant customization
> 
> is loaded, probably before any relevant file are opened.

Ahhh, this is the key piece of information that I was missing. I was confused 
by the fact that the mode declaration wasn't bothered by the fact that it came 
before the function definitions further on in the file.

> >From what I can see from your examples above, it might be enough just to
> 
> have:
> [...]
> Then, *every time* the user activates this
> 
> mode, constructs are created out of whatever's in `content-list'.
 
The creation uses add-to-list, which checks for duplicates, so that won't be a 
problem necessarily, but it does seem like unnecessary overhead that I can get 
rid of. I will play with some conditionals to see what I can do about this.

> Hope that didn't make it worse,
On the contrary, much clearer now!

To add a wrinkle to this, can someone explain how autoload changes this 
sequence? I tried to implement autoload by putting something like this in my 
file:

(autoload 'my-mode "my-name" "My Editing Mode" t)

I copied it from somewhere, but now that I read the documentation more 
carefully, I think I have two problems with this:

First, "my-name" should actually be the filename: "mymode.el". Does this 
argument care about paths?
Second, I put this line after the mode definition, but the help says:

If FUNCTION is already defined other than as an autoload,
this does nothing and returns nil.

So I think it's doing nothing (and perhaps that's why it doesn't matter that I 
didn't include the file name as I should have). It also seems it would be much 
easier to make the mode autoloaded using a magic comment, which is how I'm 
fixing it.

With regards to the order of code execution, how does autoloading the mode 
definition change what Eric already described? Users will still have(require 
'my-mode) in their .emacs, which I think executes everything except the mode 
definition.

Is it then redundant to put autoload on a function definition?


reply via email to

[Prev in Thread] Current Thread [Next in Thread]