bug#56875: 29.0.50; [PATCH] Add thread-as macro

[Richard Stallman <rms@gnu.org>]

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 > +     (thread-as x
 > +       4
 > +       (- 10 x)
 > +       (/ x 2))

I propose a different syntax which is more Lispy than thread-as, and
more self-evident:

(let-successive ((x 4
                    (- 10 x)))
  (/ x 2))

A Lisper can guess what it means, without having read a description.

It lends itself to a generalization where there is more than
one bound variable, each of which can have several values:

(let-successive ((x 4
                    (- 10 x))
                 (y 6
                    (- 12 y)))
  (* x y))
 => 36

The values after the first can refer to all of the variables,
since all of them are already bound (to the previous values)
at that point.

-- 
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)