Re: Clear trailing whitespace on save, but not at the cursor

[Doug Lewan <dougl@shubertticketing.com>]

Aaron Meurer writes:

> But it seems to me that the whole emacs lisp system is designed 
> from the ground up to do hooking (by the way, where I come from, "hooking"
> is given the much auspicious name "monkey patching").

First: 

Today I learned "monkey patching" (and, by going to Wikipedia, it's synonym "duck punching"). Thanks for giving me a techno-chuckle.

Second: 

(Assuming I understand the meaning of monkey patching) Hooks are /not/ the same thing. Hooks are favors you ask for when something happens. Hooks are easily removed. Often they are if they are badly behaved. See the documentation for after-change-functions.

Advice seem like they fit the definition of monkey patching. A piece of advice can be enabled and disabled, but it stays once it has been (defadvice)d.

The emacs lisp manual has lots of warnings about advice. It has legitimate uses, but they are rare -- typically there's-no-other-darn-way-to-do-this kind of things. It's usually worthwhile spending time to find another way because it's hard to write interesting advice that doesn't have unexpected consequences.

The emacs lisp manual has no general warnings about hooks.

There's probably something to that.

,Douglas
Douglas Lewan
Shubert Ticketing
(201) 489-8600 ext 224