Re: [O] Use default value if a variable is not defined

2012-10-12 Thread Ivan Andrus 
On Oct 11, 2012, at 6:04 PM, Nathan Neff wrote:

 Hello,
 
 I'm trying to create a function that will tell org-capture
 dynamically where to put the captured item.
 
 I have it almost working -- where I'm getting hung up on is
 with basic Emacs lisp.  I want to basically implement this
 pseudo code:
 
 IF I have defined a variable called njn/current-q-file then
(find-file njn/current-q-file)
 ELSE
   (find-file (questions.org)))
 
 However, if I do not define my njn/current-q-file then
 I get a Symbol's value as variable is void error when Emacs starts up.
 
 How do I test for the existence (and non-nil ness of a variable in Emacs)


You can use boundp.  So 

(if (boundp 'njn/current-q-file)
njn/current-q-file
  questions.org)

can be used wherever you need it.

-Ivan

[O] Use default value if a variable is not defined

2012-10-11 Thread Nathan Neff 
Hello,

I'm trying to create a function that will tell org-capture
dynamically where to put the captured item.

I have it almost working -- where I'm getting hung up on is
with basic Emacs lisp.  I want to basically implement this
pseudo code:

IF I have defined a variable called njn/current-q-file then
(find-file njn/current-q-file)
ELSE
   (find-file (questions.org)))



However, if I do not define my njn/current-q-file then
I get a Symbol's value as variable is void error when Emacs starts up.

How do I test for the existence (and non-nil ness of a variable in Emacs)

Thanks,
--Nate