Fwd: PROPOSAL: Elvis operator

[Olivier Chorier]

---------- Forwarded message ----------
From: Olivier Chorier <lapsus63 at gmail.com>
Date: 2009/3/21
Subject: Re: PROPOSAL: Elvis operator
To: Marek Kozieł <develop4lasu at gmail.com>


using : ...using a loop
(an unexpected shortcut sent the mail sorry)


2009/3/21 Olivier Chorier <lapsus63 at gmail.com>

> Ok, what about :
>
> int value ?= object.getSubObject().getValue()  : -1;
>
> Pros :
>  - I think the compiler could easily retranscript it using
>  - Much more readable
>
> Cons :
> - The potential problem is that the "interpretation" differs from an &= or
> += operator
>
> 2009/3/21 Marek Kozieł <develop4lasu at gmail.com>
>
> 2009/3/21 Olivier Chorier <lapsus63 at gmail.com>
>>
>>> I initially thought it was a good idea, but after a bit reflection, I
>>> don't
>>> think it is a real 'plus' compared with the ternary operator.
>>>
>>> For example, how would you simplify those lines of code (assuming the
>>> coder
>>> loves ternary operator) :
>>>
>>> int value = object == null ? -1 :
>>>                (object.getSubObject() == null ? -1 :
>>>                        (object.getSubObject().getValue() == null ? -1 :
>>>                               object.getSubObject().getValue()));
>>>
>>> Does somebody has an idea (excepting using an ugly try-catch statement)
>>> to
>>> write this much clearer ?
>>> (sorry for code indentation)
>>>
>>>
>>> 2009/3/21 Stephen Colebourne <scolebourne at joda.org>
>>>
>>>
>>>
>>> You wrong, this should look like:
>>
>> int value = object.?getSubObject().?getValue() ?: -1
>>
>> But there is another problem that I would like to see handled:
>>
>> What if we have default SubObject which we can use when main one is null,
>> and it's ugly generic:
>>
>> SubObject<FirstType,SecondType,TirdType,.......> subObject =
>> object.?getSubObject() ?: default;
>>
>> int value = subObject.?getValue() ?: -1;
>>
>> // here we can use subObject
>>
>> now same in other syntax:
>>
>> int value = object.?getSubObject() ?:( subObject )  .?getValue() ?: -1;
>>
>> and other syntax:
>>
>> object.?getSubObject() :: subObject;
>>
>> int value = ( subObject ?: default ).?getValue() ?: -1;
>>
>> // here we can use subObject
>>
>> and other:
>>
>> int value = ( object.?getSubObject() ?: default ).?getValue() ?: -1;
>>
>> Consider witch is easier to read.
>> --
>> Pozdrowionka. / Regards.
>> Lasu aka Marek Kozieł
>>
>> http://lasu2string.blogspot.com/
>>
>
>