[Tutor] best practice: throw exception or set a flag?

Alex Hall mehgcap at gmail.com
Fri Feb 4 18:36:02 CET 2011


I see, thanks!

On 2/4/11, Bill Felton <subscriptions at cagttraining.com> wrote:
> Smalltalk is an OO programming language that had some dominance in the late
> 80's through much of the 90s.  It has proceeded to more or less commit
> suicide through a variety of mechanisms.
> By 'drop' I meant 'drop the context of the remarks', which in the original
> post was discussing Smalltalk's default method return.
> It isn't a major deal, overall, I think the most interesting remark has been
> Alan Gauld's musings immediately prior to Emile's to which I responded.
> Python defaults to None.
> Smalltalk defaults to self, which is always the object executing the code
> involved.
> Alan points out that this is extremely convenient and can reduce the code
> bulk involved when one wishes to string multiple operations together.
> It is stylistically possible in Python to set methods to return 'self'
> if/when that would be useful, but if it is not a language level feature, it
> becomes a convention that one can only rely on in ones own code.
>
> regards,
> Bill
>
> On Feb 4, 2011, at 11:56 AM, Alex Hall wrote:
>
>> On 2/4/11, Bill Felton <subscriptions at cagttraining.com> wrote:
>>> Um, yes, emphatically yes.  You missed the context, which was Smalltalk,
>>> and
>>> it is terms of Smalltalk that my reply is couched.
>>> Yes, Python returns None.
>>> Smalltalk returns self by default.
>>> Given the dropped context, you are correct.
>>> Given the context meant, I am.
>> I was following this until now... what is this smalltalk and drop?
>>>
>>> regards,
>>> Bill
>>>
>>> On Feb 4, 2011, at 9:28 AM, Emile van Sebille wrote:
>>>
>>>> On 2/4/2011 5:35 AM Bill Felton said...
>>>>
>>>>> Um, not quite correct -- methods *without a specified return value*
>>>>> always return self, that is, the object which executed the method.
>>>>
>>>> Um, no.  They return None.
>>>>
>>>>>>> class Test:
>>>> ...   def __init__(self):pass
>>>> ...   def test(self):pass
>>>> ...
>>>>>>> a=Test().test()
>>>>>>> a
>>>>>>> print a
>>>> None
>>>>>>>
>>>>
>>>> Emile
>>>>
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>>
>>
>> --
>> Have a great day,
>> Alex (msg sent from GMail website)
>> mehgcap at gmail.com; http://www.facebook.com/mehgcap
>
>


-- 
Have a great day,
Alex (msg sent from GMail website)
mehgcap at gmail.com; http://www.facebook.com/mehgcap


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