[cells-devel] laziness -- what does "once-asked" mean?

[Kenny Tilton]

Kenny Tilton wrote:
> Larry Clapp wrote:
> 
>> I understand (I think ...) what :once-asked *does*, I want to know
>> what it *means*.
>>
>> In other words, the other two options seem to answer the question
>> "when is this cell lazy?"  Well, an :always cell is always lazy --
>> it's not recalculated until and unless you ask for it.  An
>> :until-asked cell is lazy until you query it once, then it's non-lazy
>> from then on.
>>
>> "once-asked" seems to answer a *different* question, "when is this
>> cell evaluated?"  It's evaluated once, when created, and then only
>> when queried.
>>
>> Is there any single "question" that all three answer, or are they just
>> inconsistent?
> 
> 
> Once-asked would be "un-lazy until you query it once" (ie, consistent) 
> but it also looks to be vestigial: all code seems to treat it the same 
> as always.
> 
> If I missed it in my brief scan of the code, it would have to do with 
> model instance initialization. 

Yeah, looks like I missed it, because the code looks for other than 
:once-asked to break off initialization and I was just searching on 
once-asked.

kt


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