Re: About features

[Xue Fuqiao]

> > > > Why should we use `provide' and `require'? Is
> > > > `load'/`load-library'/`load-file'
> > > > enough? Thanks.

> > > `provide' allows you to `require' unconditionally, but the library/file
> > > will
> > > only be loaded if necessary.

> > Can you explain it more detailed?

> Simplifying, it's something like:

> (defun require (feature)
>   (if (not (member feature features))
>       (load feature)))

> (defun provide (feature)
>   (if (not (member feature features))
>       (push feature features)))

> As I said in my earlier response: require won't reload a library if it's
> already been loaded, and it uses the features variable to keep track of
> which libraries have been loaded this way.

I see.  Thanks, I misunderstood your meaning before. (My English sucks.)

--
Best regards, Xue Fuqiao.
http://www.emacswiki.org/emacs/XueFuqiao