Re: How do I determine if a function is defined?

[Bruce Korb]

Bill Gribble wrote:
> 
> On Sun, 2002-04-28 at 14:15, Clinton Ebadi wrote:
> > Try (if (procedure? 'mumble) (mumble)). Remember to quote the variable you
> > want to test!
> 
> No, (procedure? 'mumble) is always #f, because 'mumble is a symbol, not
> a procedure, even if there is a procedure bound to the variable mumble.
> 
> What are you trying to do in the larger scheme of things?  It's pretty
> darn unusual to really need to write code that doesn't know which
> symbols are bound.  And sketchy.

I have a program that defines the procedure ``set-writable''

 http://www.gnu.org/manual/autogen-5.3.6/html_chapter/autogen_3.html#SEC62

but I added that procedure only recently.  I want to use it if it is
available, but skip it if it is not.  That way, I do not require
that people have an AutoGen version more recent than a year old.