Path: utzoo!mnetor!uunet!husc6!bloom-beacon!mit-eddie!uw-beaver!ssc-vax!bcsaic!lbaum
From: lbaum@bcsaic.UUCP (Larry Baum)
Newsgroups: comp.lang.lisp
Subject: Re: query 'bout defstruct (Common LISP)
Message-ID: <5190@bcsaic.UUCP>
Date: 3 May 88 20:59:20 GMT
References: <10834@cgl.ucsf.EDU>
Reply-To: lbaum@bcsaic.UUCP (Larry Baum)
Organization: Boeing Computer Services AI Center, Seattle
Lines: 28
Keywords: defstruct, symbols, confusion

In article <10834@cgl.ucsf.EDU> yee@cgl.ucsf.edu (dave yee) writes:
>i would like to define a data structure using defstruct.  
>
>...  Now for the tricky part.  I will have a variable
>number of "pieces" at any given time in the program.
>So i would like the computer to
>generate new symbols for me.  The new symbols would then
>be used as names for the new pieces. 
>
>Now, i figured i could use "gentemp" to make the symbols,
>but i can't "setq" these new symbols (i.e.
>(setq (gentemp) (make-piece)) just doesn't cut it...
>

You could do: (set (gentemp) (make-piece))

However, while this will successfully do the binding, it will defeat
your goal of having a name for your object, since the symbol returned
by (gentemp) has been lost.  Better would be:

(let ((symb (gentemp)))
   (set symb (make-piece))
   ... code to get a handle on symb ...)

If you are going to have many, many pieces, then storing them in a hash
table will probably give to better performance.

LSB