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[Python-Dev] Every Release Can Be a Mini "Python 4000", Within Reason (was (name := expression) doesn't fit the narrative of PEP 20)


On 30/04/2018 07:22, Greg Ewing wrote:
> Jeff Allen wrote:
>> I speculate this all goes back to some pre-iteration version of 
>> FORmula TRANslation, where to its inventors '=' was definition and 
>> these really were "statements" in the normal sense of stating a truth.
>
> Yeah, also the earliest FORTRAN didn't even *have* comparison
> operators. A conditional branch was something like
>
I should have known that would turn out to be the most interesting part 
in my message. Not to take us further off topic, I'll just say thanks to 
Eitan's reply, I found this:
http://www.softwarepreservation.org/projects/FORTRAN/BackusEtAl-Preliminary%20Report-1954.pdf

They were not "statements", but "formulas" while '=' was assignment (sec 
8) *and* comparison (sec 10B). So conversely to our worry, they actually 
wanted users to think of assignment initially as a mathematical formula 
(page 2) in order to exploit the similarity to a familiar concept, 
albeit a=a+i makes no sense from this perspective.

Jeff Allen

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