Re: CPAN-river: can graph calculation be modified?

On 02/02/2018 10:51 AM, Neil Bowers wrote:
>> For the 5.29.* development cycle starting in May of this year, I would 
>> like to be able to use a ranking of CPAN distros which goes beyond asking:
>>
>> * "How many other distributions depend on this one?"
>>
>> ... to asking:
>>
>> * "How many distributions by other authors/maintainers depend on this 
>> one?"
>>
>> Would that be feasible?  Has anyone attempted this already?
> 
> When we were discussing the River model at QAH, and in discussions 
> afterwards, this came up. In the end we decided to keep things simple 
> and go with the current common definition. There are some tools in the 
> CPAN ecosystem that only count dependencies written by others.
> 

Can you point us toward those tools?

> We’d need to agree which dists get ignored in this alternate scheme. 

Please note that I'm not looking to replace the current definition.  I'm 
looking to develop supplementary definition(s) -- and their 
implementations -- that can be useful in particular circumstances.

> Consider this example:
> 
> 
> Here MARY has released a bunch of dists, but Foo-Bar is also relied on 
> by other dists written by MUNGO and MIDGE.
> 
> The river count for Foo-Bar would be 2 here (ignoring the whole branch 
> that contains only dists from MARY), but the Foo river count should be 
> 3, I think. Foo-Bar “counts”, because it in turn is depended on by dists 
> from other authors. Otherwise the river count would be 2 for both Foo 
> and Foo-Bar. Basically we’re starting at the “bottom" of the dependency 
> graph, and trimming sub-graphs all from one author.
> 
> Also consider this example:
> 
> 
> What’s the river count of Plant — 0, 1, or 3? I think it should be 1, in 
> this alternate measure.
> 
> I.e. for sub-graphs by the same author, you only include the dist at the 
> head of the sub-graph.
> 
> It would be useful to have both measures available: raw-river and 
> author-river.
> 
> When looking at a dist there are (at least) three figures that might be 
> of interest: the full river count (total number of direct and indirect 
> dependencies), the author-filtered river count (as above), and the 
> number of direct dependencies (which could be split in 2 as well).
> 
> Neil
> 

Thank you very much.
Jim Keenan