[ruby-core:41758] Re: My bug evaluation criteria

(2011/12/18 13:53), Marc-Andre Lafortune wrote:
> On Sun, Dec 11, 2011 at 8:59 PM, NARUSE, Yui <[e-mail]> wrote:
> 
>> ...
>>> To pass the "strict superiority test" (SST), the proposed behavior is judged on:
>>> a) usefulness,
>>> b) consistency,
>>> c) intuitiveness and
>>> d) big O level of performance
>>> It must be superior to the existing behavior on at least one of these
>>> criteria, and not inferior in any.
>>
>> I add one more, the value of behavior's brekage is prior than compatility.
> 
> Sorry, I'm not sure I understand your sentence.

In other words, the *fix* is worth breaking compatibility
or changing the behavior.

>>> A bugfix is "clear" if it is straightforward (SST+NIT) and if the
>>> existing behavior passes the "clear defect test" (ODT):
>>> 1) it crashes Ruby,
>>> 2) it contradicts the documentation or
>>
>> On Ruby, a document and code sometimes conflict.
>> On such case, they theirselves are equal, but as I wrote above,
>> code change introduces incompatibility.
>> So usually the code is prior to the documentation.
> 
> If a behavior is not intentional (as per test above) and contradicts
> the documentation (i.e. the documentation explicitly states some
> result which differs from the current result), I have to disagree with
> you: it's a clear bug, the code is wrong and the documentation should
> be followed. Of course, it's possible to decide to make a feature
> change at this point, change the documentation, etc..., but it is not
> a bug fix.

There are some cases that the document should be fixed:
* the documentation seems wrong.
  On Proc#arity's case, "optional arguments" seems to be "rest arguments"
  because tests and examples in the document convers only rest arguments.
* there are many programs depend on the current behavior.
  You may know HTML5's willful violations.
* the method is deprecated.
  The method is not worth changing; in other word WONTFIX.

>>> 3) it is platform dependent (when it can reasonably be platform independent)
>>
>> What is "reasonably be platform independent" is not clear yet,
> 
> You are right, it's not clear for all cases, but for many cases it is
> clear. Having to rewrite a huge library is not reasonable, changing a
> couple of lines of code is. Impacting the performance by a factor of
> 10 isn't reasonable, but a slowdown of a couple of percent is.

Your work, making ruby's float behavior portable, is the case.

-- 
NARUSE, Yui  <[e-mail]>