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PROG1 as a function



   Date: Wed, 4 Jan 89 13:34:57 pst
   From: Eric Benson <eb@lucid.com>

      Date: Wed, 4 Jan 89 16:23:48 EST
      From: Guy Steele <gls@Think.COM>

      Sigh.  Unfortunately, I must beg to differ.  I read the passage on page 194
      as requiring only that the fully evaluated arguments be processed
      left-to-right for contagion purposes.  This is not the same as requiring
      that argument forms in a call be evaluated left-to-right.

      -- Guy


   Maybe you're looking at the wrong passage.  This looks pretty
   unambiguous to me.  It's also the only place in CLtL that says
   argument evaluation is always left-to-right:

   "For functions that are mathematically associative (and possibly
   commutative), a Common Lisp implementation may process the arguments
   in any manner consistent with associative (and possibly commutative)
   rearrangement.  This does not affect the order in which the argument
   forms are evaluated, of course; that order is always left-to-right, as
   in all Common Lisp function calls.  What is left loose is the order in
   which the argument values are processed."

Ooops.  Sorry.  I was wedged and looking in the wrong place.

"Never mind."

--Guy