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Re: Code for cond*

From: Richard Stallman
Subject: Re: Code for cond*
Date: Fri, 19 Jan 2024 22:39:38 -0500

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  > apologies if it was discussed already, wanted to ask: what is the reason
  > for some of these cond* clauses to keep the binding in effect outside
  > the clause itself and for the whole cond* construct?

One of the long-bemoaned inconveniences of cond is that often in
mid-cond one wants to bind some variables and then proceed with more
cond clauses.  Lisp programmers have complained about this for
decades.  Sure, you can do

  (t (let ((temp (cadr whatsis)))
       (cond ((eq temp 'foo))

but this  increases the indentation by 11 columns.
bind* gives the same effect without deeper nesting.

Consider the definition of cond*-subpat.  If I rewrite that using
cond*, I would bind a variable to (car subaat) after the clauses that
deal with atomic subpatterns.

Dr Richard Stallman (https://stallman.org)
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)

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