completely agree. contracts must be permanent.
Thanks. Dmitry.
On Tue, Feb 10, 2015 at 10:40 AM, Joe Watkins <pthre...@pthreads.org> wrote:
> Example code never works, I can just say that's a bad abstraction,
> vertebrate and invertebrate are distinct and abstraction should reflect
> that.
>
> Why should we provide a way to change contracts is the question ?
>
> It doesn't seem to make sense to do that, a derived class should be able
> to define additional contracts, but not change the contracts of it's parent.
>
> Cheers
> Joe
>
> On Tue, Feb 10, 2015 at 7:36 AM, Yasuo Ohgaki <yohg...@ohgaki.net> wrote:
>
>> Hi Joe,
>>
>> On Tue, Feb 10, 2015 at 4:31 PM, Joe Watkins <pthre...@pthreads.org>
>> wrote:
>>
>>> Actually I'm not sure it's at all sane to try to override contracts, I'd
>>> actually avoid that completely, so no need to name contracts and no need
>>> for magic __invariant.
>>
>>
>> For example,
>>
>> class Animal {
>> protected $legs;
>> require($legs >= 0);
>> }
>>
>> class Snake extends Animal {
>> // Snake is fine, no leg
>> }
>>
>> class Human extends Animal {
>> // 2 legs. $this->leg === 2
>> }
>>
>> Overriding makes sense for many cases.
>>
>> Regards,
>>
>> --
>> Yasuo Ohgaki
>> yohg...@ohgaki.net
>>
>
>
