Russ Allbery said:
>> Can we get rid of that "estimated" from "estimated number of articles in
>> the group"? As far as I am concerned, an estimated value is worse than
>> useless, and an NNTPv2 compliant server should be required to give an
>> exact value.
>
> An exact value at the time that the command is issued that may have
> changed a second later doesn't strike me as much more useful than an
> estimated value.
Furthermore, it may require significant resources to compute.
The specification of GROUP states:
If the group is not empty, the estimate MUST be at least the
actual number of articles available, and MUST be no greater
than one more than the difference between the reported low and
high water marks. (Some implementations will actually count
the number of articles currently stored. Others will just
subtract the low water mark from the high water mark and add
one to get an estimate.)
I see no reason to change this (the case of an empty group is discussed in
the following paragraphs and is also, IMO, fine).
>> What is a "reported" high and low water mark as opposed to a high and
>> low water mark?
> Same thing. I'm not sure why the word "reported" is there, but it's used
> fairly consistently through the rest of the draft as well.
"reported" is shorthand for "at the moment of selection":
The successful selection response will return the article
numbers of the first and last articles in the group at the
moment of selection (these numbers are referred to as the
"reported low water mark" and the "reported high water mark"),
to prevent pedants claiming that these LWM and HWM mustn't change later
(because the response would become retroactively wrong).
[Range of 5-1]
>> If it is it an error, then there needs to be an error code.
> That's a very good question, and one that we also need to answer for OVER,
> which has the same issue.
In OVER an empty range *is* an error (423) but in LISTGROUP it isn't.
So we do have a different situation here. I would suggest we have three
possible resolutions for an impossible range like 5-1:
211 and an empty list
501 (it's pretty obviously a syntax error)
423 (consistency with OVER)
>> Your first two examples have two extraneous spaces after the command.
>> Are these significant for some reason?
> I think they were intended to be examples that whitespace doesn't matter
> (they're in the existing LISTGROUP writeup).
The pre-processor I use inserts them, partly to show that whitespace
doesn't matter and partly to more clearly separate command and arguments.
--
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