Concrete Proposal: while ... and while ...

[Andrew M. Kuchling]

Paul Prescod writes:
>"Michael P. Reilly" wrote:
>> I'd be interested in knowing how many people would change from the
>> common idioms to this proposed syntax.

	I'd love a do... while in Python; its absence is probably my
single biggest problem with Python.

>The current proposal allows me to say what I mean about looping which
>brings Python closer to being executable pseudo-code. do/while would be
>even better but may not be worth the code breakage (though I am curious
>how much code breakage there would really be).

	I don't see why do...while would break code.  It would
probably look like this:

do:
    L = f.readline()
while regexpattern.match(L) is None

'while' without a colon is a syntax error, unless preceded by a 'do'.
'while' with a colon is the same as it is now.  I don't see how
'do'...'while' would be difficult to implement (though I admittedly
haven't tried to implement it).  'while' with a colon and subsequent
statement block would also be acceptable.

-- 
A.M. Kuchling			http://starship.python.net/crew/amk/
The Law, in its majestic equality, forbids the rich, as well as the poor, to
sleep under the bridges, to beg in the streets, and to steal bread.
    -- Anatole France