Re: [gobo-eiffel-develop] Iterators for DS_TABLE?

[Eric B. <er...@go...>]

Colin Adams wrote:
> On 20/03/2008, Eric Bezault <er...@go...> wrote:
> 
>> These feature names suggest that only the key is passed to the
>>  agent. I think that we need the three kinds of iterators:
>>  over the items, over the keys, and over both. The most difficult
>>  part is to find names. What about `do_all', `do_all_key' and
>>  `do_all_keyed'? Any better suggestion?
>>
>>  Well, in fact to iterate only on keys I guess we can do
>>  `my_table.keys.do_all'... So, we might need only two kinds of
>>  iterators after all. What about `do_all' and `do_all_with_key',
>>  the latter being similar to `do_all_with_index'?
> 
> Yes, that sounds the best compromise.
> 
>>  Note that DS_TABLE is not linear. Only DS_SPARSE_TABLE is.
>>  I don't remember why DS_TABLE is not linear, but I'm not
>>  currently in a mood to change that to make it linear.
> 
> There is nothing linear about for_all_with_keys and there_exists_with_keys.
> Do_all_with_index/do_if_with_index imply a linear ordering, so we
> won't want them in DS_TABLE.

I should have said that DS_TABLE is not a descendant of
DS_TRAVERSABLE (rather than a descendant of DS_LINEAR).

I would say that `do_all_with_index' belongs to DS_INDEXABLE.
It has been added to DS_LINEAR for convenience (perhaps
DS_LINEAR should have been a descendant of DS_INDEXABLE).

> I see no implied linearity with
> do_all_with_keys, do_if_with_keys (or for that matter do_all and
> do_if, just from the names). It all depends upon what the header
> comment says. So for do_all_with_keys we can just word the header
> comment to state that no particular order may be relied upon. Likewise
> for do_if_with_keys. 

If we follow the same reasoning, that `do_all', `there_exists',
etc. should be moved to DS_CONTAINER.

-- 
Eric Bezault
mailto:er...@go...
http://www.gobosoft.com