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Date:Mon Aug 17 00:44:20 1999 
Subject:Re: Stack manipulation syntax (WAS: A primeval C compiler) 
From:William Tanksley 
Volume-ID:990817.01 

On 16 Aug 1999 08:47:27 GMT, Aaron Sloman See text for reply address wrote:

>richard@starburst.demon.co.uk (Richard Wendland) wrote:
>> "Andy Glew" <glew@cs.wisc.edu> writes:

>> >a :=: b is cool,
>> >but I think that a,b := b,a
>> >or a := b, b := a
>> >    (where , is the "parallel" separator for unordered code)
>> >is more general, and extends to arbitrary permutations:

It also works for tuple (or list) packing and unpacking, which is Python's
excuse for allowing the same meaning :) for a,b:=b,a.

>> POP-2 had this in 1968.  Was this the first language with this feature?

>Not if forth came first?

Kind of.  There were primitive Forths around, but they didn't achieve
consciousness until a little later (source: www.forth.com, history pages).
So to speak :).

They didn't have variable flipping, but rather an open stack.

>> I've always been glad POP-2 was my first programming language.

I'm learning Lisp and Pop-11 at the same time.  The cool thing is that
Poplog includes a fairly complete Common Lisp implementation.

A pity it took me so long to start learning them.

>Aaron

-- 
-William "Billy" Tanksley