[Toybox] diff algo blog post 2022-08-27

[Rob Landley]

On 9/20/22 00:59, Rob Landley wrote:
> On 9/19/22 18:45, Ray Gardner wrote:
>> Rob, first, let me say thank you for at least looking at my post. Sorry I
>> did not see your August 27 blog post sooner. I fell behind, I thought
>> any response to my writeup would be in the list.
> 
> I try to write blog entries regularly, but it's quick dashed off things without
> all the right HTML tags and lots of [LINK find url to thingy] and sentences
> trailing off unfinished as I get distracted.
> 
> I go through and edit and upload them in batches later. Making them seem
> coherent takes far longer than initially writing them did. :)
> 
>> I am wondering if you read my post all the way through, and did it give
>> you an understanding of the actual LCS algo. Recall that I wrote it for you,
>> specifically though not only, because you (and Elliott) encouraged me to.
> 
> I still have the tab open, but I haven't had the stomach to circle back around
> to diff.c recently. (Sigh, I should get it over with.)
> 
>>> Ray Gardner wrote up his own explanation of the classic diff algorithm,
>>> and I'm trying to read it to see if it makes more sense to me than the
>>> other writeups did.
>> 
>> What other writeups did you look at, that try to explain any LCS
>> algorithms?
> 
> Other than the original toys/pending/diff.c implementation and the paper I
> emailed Doug McIlroy to get a URL to since the bell labs website everybody was
> linking to had gone down and wasn't in archive.org? (Doug beat Elliott with the
> updated URL by about 20 minutes.) And the wikipedia explanation of the algorithm
> (https://en.wikipedia.org/wiki/Diff#Algorithm)?
> 
> I've closed a lot of the tabs but here's a few that haven't cycled out of
> about:history yet:
> 
> https://blog.jcoglan.com/2017/02/12/the-myers-diff-algorithm-part-1/
> https://blog.jcoglan.com/2017/09/19/the-patience-diff-algorithm/
> https://www.quora.com/How-does-Bram-Cohens-patience-algorithm-compare-relative-to-myers-minimal-and-histogram-options-for-gits-diff-function
> https://bramcohen.livejournal.com/73318.html
> https://tiarkrompf.github.io/notes/?/diff-algorithm/aside2
> https://tiarkrompf.github.io/notes/?/diff-algorithm/
>
> There were more...

https://luppeng.wordpress.com/2020/10/10/when-to-use-each-of-the-git-diff-algorithms/

https://archive.eclipse.org/jgit/docs/jgit-2.0.0.201206130900-r/apidocs/org/eclipse/jgit/diff/HistogramDiff.html

There were still more...

Rob