Re: Shrinking EIEIO objects

[Eric Ludlam <ericludlam@gmail.com>]

On 01/02/2015 06:22 AM, David Engster wrote:
> Eric Ludlam writes:
>> On 12/30/2014 12:59 PM, Stefan Monnier wrote:
>>> Hi Eric,
>>>
>>> I'd like to install something like the patch below into Emacs's master.
>>> What it does (along with various other side changes) is shorten the
>>> object header from 3 fields (the constant `object', the class name, and
>>> an object "name" field) to just one (an interned symbol with an "eieio-"
>>> prefix, referring to the class object).
>> This seems like a fine idea.  A side effect is that the 'name' slot is
>> gone.  There have received a questions about why there is a 'name' for
>> objects, and really the main thing was debugging.  When you have piles
>> of objects around, naming them makes it much easier to see what is
>> going on.   EIEIO objects have a short hand using a #<class name>
>> format, and when the various prin1 tools are enabled for edebug, that
>> short hand is used in place of the vector.  This is critical when
>> debugging semantic databases where the vectors contain thousands of
>> symbols.
>>
>> Your proposed solution will enable the current source forge hosted
>> version of CEDET to keep going, just with warning messages, which
>> seems fine.
>>
>> I can convert the sourceforge version CEDET to use make-instance
>> instead, which should be compatible before and after your change.
> I'm a bit confused. Why would we need to change how we construct our
> objects? Most of these changes seem to be purely internal. The only API
> change I see (aside from the added eieio-- prefixes) is that NAME is now
> optional (but not obsolete), which is certainly a good thing.

In the patch, the generated constructor method calls 'message' if the 
first slot is a string (which is the now optional name input), and the 
message says the name input is obsolete, and also no longer saves the name.

>> While reading through the patch, there was a bunch of changes related
>> to doc strings and methods.  The goal was if you used help on a
>> method, such as:
>>
>> C-h f constructor RET
>>
>> (or eieio-constructor in your patch)
>>
>> it should list the core doc (generic) and doc for every class that has
>> it's own implementation and custom doc.  I couldn't intuit from the
>> patch what might happen as some of the doc strings looked like they
>> were removed?
> I don't think that has changed. I just tried Emacs with the patch and I
> see the "EIEIO-enhanced" docs as usual.

Great!   Thanks for checking.

Eric