Re: Is this PEP-able? fwhile

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From	Ian Kelly <ian.g.kelly@gmail.com>
Date	Tue, 25 Jun 2013 10:00:54 -0600
Subject	Re: Is this PEP-able? fwhile
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On Tue, Jun 25, 2013 at 1:21 AM, Chris Angelico <rosuav@gmail.com> wrote:
> On Tue, Jun 25, 2013 at 2:20 PM, Benjamin Kaplan
> <benjamin.kaplan@case.edu> wrote:
>> The reason I was given (which I promptly ignored, of course) is that
>> it's "best practice" to only have one exit point for a block of code.
>> Only one way of terminating your loop, only one "return" per function,
>> never use exceptions, etc. I think it originally came about as a way
>> to make sure that your clean-up code was called (and to make it easier
>> for code reviewers to make sure your clean up code was called) and
>> then started being passed around as a rule among programming teachers
>> who didn't have any experience outside the classroom.
>
> I've heard that "one exit point" rule before, too, but never any
> justification for it. Your explanation does at least make sense
> (albeit only in a language without even RAII), but I don't like silly
> rules like that :)

In my experience the sorts of people who preach "one exit point" are
also all about defining preconditions and postconditions and proving
that the postconditions follow from the preconditions.  I think that
the two are linked, because the "one exit point" rule makes those
sorts of proofs simpler.

Thread

Re: Is this PEP-able? fwhile Chris Angelico <rosuav@gmail.com> - 2013-06-25 07:38 +1000
  Re: Is this PEP-able? fwhile rusi <rustompmody@gmail.com> - 2013-06-24 19:01 -0700
    Re: Is this PEP-able? fwhile Chris Angelico <rosuav@gmail.com> - 2013-06-25 13:54 +1000
    Re: Is this PEP-able? fwhile Benjamin Kaplan <benjamin.kaplan@case.edu> - 2013-06-24 21:20 -0700
    Re: Is this PEP-able? fwhile Chris Angelico <rosuav@gmail.com> - 2013-06-25 17:21 +1000
    Re: Is this PEP-able? fwhile Ian Kelly <ian.g.kelly@gmail.com> - 2013-06-25 10:00 -0600
      Re: Is this PEP-able? fwhile rusi <rustompmody@gmail.com> - 2013-06-25 09:19 -0700
        Re: Is this PEP-able? fwhile Neil Cerutti <neilc@norwich.edu> - 2013-06-26 13:09 +0000
    Re: Is this PEP-able? fwhile Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-06-25 20:40 -0400
      Re: Is this PEP-able? fwhile jfharden@gmail.com - 2013-06-26 03:00 -0700
      Re: Is this PEP-able? fwhile Jerry Peters <jerry@example.invalid> - 2013-06-26 19:56 +0000

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