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Re: How do I determine if a function is defined?
From: |
Bruce Korb |
Subject: |
Re: How do I determine if a function is defined? |
Date: |
Sun, 28 Apr 2002 12:09:59 -0700 |
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.