Re: Standard Queue status

[Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov>]

Ted Dennison<dennison@telepath.com> writes:

> To get things back on track, I'd like to ask if there is anything in Nick's
> proposal that there is general consensus on putting in the strawman (or we could
> take it the other way, if that's what folks want). If you want to look at it,
> the package in question is at
> http://www.adaos.ukf.net/njr05/scl-lists-unbounded.ads.html .

I'd like to suggest a slightly different approach. 

I would find it useful to have a list of criteria, so that we can
judge each candidate by that criteria. For example, one criterium is
that the user be able to get a list package with a single
instantiation. Other criteria have been proposed, such as "lists must
be safe (ie no dangling pointers, etc) against _any_ iterator
operation". That criteria separates Ted's strawman from Nick's.

If we can all agree on what the criteria are, it will be easier to
agree on the package design. The criteria list should mention all of
the criteria that have been proposed, and say whether the consensus is
to keep it or not.

Here are some criteria I remember from this discussion:

user must be able to get a list package with a single
instantiation. 

lists must be safe (ie no dangling pointers, etc) against _any_ list
or iterator operation

lists must be efficient enough for hard real-time use

lists must be safe in a multitasking environment

lists must not be a tagged type

lists must be safe for assignment (always do deep copy, or don't allow
assignment).

list elements must not be private

lists must support elements of any Ada type (private, limited, tagged,
indefinite)

Ted (or Nick); can you post this list on your web page, and try to
keep track of votes for and against each one?

-- 
-- Stephe