From: Scott Alexander
Subject: Possibly inefficient macro bind a list of symbols to function defs
Date: Sun, 13 Mar 1994 01:02:15 +0000
Message-ID: <CMKw7r.JFx@world.std.com>

RE:  My previous post
     Trying to write a macro which takes a list of symbols
     and binds each symbol to a function definition using 'defun'


The following code seems to do what I want:

   (defmacro defsums (symbol-list)
       (dolist (s symbol-list)
         (eval `(defun ,s (x y) (+ x y)))))

After evaluating the above, evaluation of a form like

   (defsums (add-up total sigma))

defines three new functions, so

   (add-up 2 3)

returns '5'.


Is the use of 'eval' in the above macro definition terribly
inelegant or inefficient, or is it the only way to go?  

I was under the impression that a macro call, once fully expanded,
still gets evaluated once as well, and I have heard that calls
to 'eval' are inefficient and usually avoidable, so I suspect
there may be a better way of coding the above macro 'defsums'.

Thanks for any help!

Scott Alexander

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