Bug? Won't eval an 'if' sexp?

Bug? Won't eval an 'if' sexp?

[Hacksaw]

I added this to my .emacs under version 20.7:

(if (eq (user-uid) 0)
	(message "You're uid 0, no desktop")
	(lambda ()
	  (message "setting up desktop")
	  (custom-set-variables
	   '(desktop-enable t nil (desktop)))
	  (desktop-load-default)
	  (desktop-read)
	 )				
)


It worked just fine. Under 21.2 it's not evaluated correctly. Doing a eval lst 
sexp, it returns the lamda, I guess implying that it's not evaluating it?

[What I see in the *Message* buffer]

(lambda nil (message "setting up desktop") (custom-set-variables (quote 
(desktop-enable t nil ...))) (desktop-load-default) (desktop-read))

Anyone know what's up?
-- 
Life is too short to take on the unnecessary.
http://www.hacksaw.org -- http://www.privatecircus.com -- KB1FVD

Re: Bug? Won't eval an 'if' sexp?

[David Kastrup]

Hacksaw <hacksaw@hacksaw.org> writes:

> I added this to my .emacs under version 20.7:
> 
> (if (eq (user-uid) 0)
> 	(message "You're uid 0, no desktop")
> 	(lambda ()
> 	  (message "setting up desktop")
> 	  (custom-set-variables
> 	   '(desktop-enable t nil (desktop)))
> 	  (desktop-load-default)
> 	  (desktop-read)
> 	 )				
> )
> 
> 
> It worked just fine. Under 21.2 it's not evaluated correctly. Doing
> a eval lst sexp, it returns the lamda, I guess implying that it's
> not evaluating it?

Whoever gave you the idea it should?  You want to use progn here, not
lambda.

Actually, you don't need to use even progn here: everything beyond
the first clause of an if-form belong to the else-part.

Please start using C-h f on functions/forms you have no clue about.
Better yet, read an introduction to Lisp.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum

Re: Bug? Won't eval an 'if' sexp?

[Hacksaw]

>Whoever gave you the idea it should?  You want to use progn here, not

Why should lambda not work here? This form, untouched, worked in emacs 20.7.


-- 
When we have nothing to say, it is very hard to say nothing.
When we have nothing to do, it is very hard to do nothing.
http://www.hacksaw.org -- http://www.privatecircus.com -- KB1FVD

Re: Bug? Won't eval an 'if' sexp?

[David Kastrup]

Hacksaw <hacksaw@hacksaw.org> writes:

> >Whoever gave you the idea it should?  You want to use progn here, not
> 
> Why should lambda not work here? This form, untouched, worked in
> emacs 20.7.

It should never have worked in the first place, but did so due to an
Emacs quirk.  lambda is a form supposed to return a function, not
execute it.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum

Re: Bug? Won't eval an 'if' sexp?

[Hacksaw]

>lambda is a form supposed to return a function, not execute it.

Ah, it's coming back... it's been a few years since I have used lisp.

Thanks for the advice, removing the lambda form all together worked, no 
surprise.

-- 
Suffering is our experience of the distance between what we are and who we 
wish to become.
http://www.hacksaw.org -- http://www.privatecircus.com -- KB1FVD