Thanks. I am going to use it a lot more. If I get more examples, should I post a follow up? Or leave it for others to jump in?
On Mon, Aug 5, 2024, 7:26 AM Viktor Klang <viktor.kl...@oracle.com> wrote: > Hi David, > > Thank you for the write-up—sharing your experience with us. > > I'm happy you've had much success with `windowBy`, and we're going to have > to wait and see what other feedback on Gatherers and potential unmet needs > in the roster of baked-in Gatherers. > > Gatherers is scheduled to have a second preview in Java 23, in order to > give users a chance to try it out and share their experience. > > Cheers, > √ > > > *Viktor Klang* > Software Architect, Java Platform Group > Oracle > ------------------------------ > *From:* David Alayachew <davidalayac...@gmail.com> > *Sent:* Sunday, 4 August 2024 09:14 > *To:* core-libs-dev <core-libs-dev@openjdk.org> > *Cc:* Remi Forax <fo...@univ-mlv.fr>; Viktor Klang < > viktor.kl...@oracle.com> > *Subject:* [External] : Gatherers -- windowBy > > Hello Core Libs Dev Team, > > Apologies for the massive delay. I have been juggling many severe personal > emergencies, and thus, did not have time or strength to follow up on the > previous thread -- > https://mail.openjdk.org/pipermail/core-libs-dev/2024-January/117718.html > > As mentioned in my previous thread, I have been extremely happy with the > new Gatherers API, and have found numerous uses for it. > > I did want to add one addition to the list of premade gatherers provided > by the standard library in java.util.stream.Gatherers API -- a windowBy > gatherer. > > The result of the thread was that, while the feature had nothing wrong > with it, evidence needed to be provided of its utility. This email is that > evidence. Specifically, this email is providing all of the situations where > I used this windowBy Gatherer that Viktor Klang made for me, with the hope > that it is strong enough evidence to push this method into the Gatherers > API. > > Here we go. > > 1. Advent of Code 2020 -- Day 14 [1] -- and here is my code [2] -- > here is a link to the line that actually used the gatherer [3] > 1. This cleaned up my solution CONSIDERABLY. If I was doing this with > for loops, I would have to do index manipulation to jump ahead my for > loop > index wise. Here, all I am doing is telling it how to split apart the > stream. Way more clear and elegant. Which was critical because this AOC > day > was extremely difficult for me. Solution is not yet done, but making > great > progress. > 2. Service Health Analytics -- Work project, so I can't share the > code > 1. This was a super basic use case, but long story short, I'm > tracing down yet another network issue, and I wanted to know what was > occurring before the network outage, to see if there was a correlation. > I > ended up scrapping this solution in favor of another one, but I was > quite > happy with how easy the Gatherer made it to grab exactly what I wanted. > It > was just a windowBy followed by a sliding window, and then extracting > some > info by comparing the 2 chunks. > 3. Typing Metrics [4] -- here is the link to the method that uses > the Gatherer [5] > 1. This is where I really put the Gatherer through its paces. I had > some semi-complex examples, but I got them all to work out well. It > made my > logic simpler than the imperative equivalent, while also keeping things > concise. Now, one point that caused me some difficulty was recognizing > that > the Gatherer has a surprisingly large number of edge cases. For example, > when looking at the data in aggregate, you notice a pattern -- the first > element of every window is the FALSE case of your predicate, while all > remaining members of that window are the TRUE case of the predicate. > However, it's very possible for the first window to be a single element > TRUE case window. I think this is the first time I found a valid use for > the Stream::dropWhile method lol. But otherwise, this feature REALLY > helped > me move forward, and I am very happy with it! > > My biggest takeaway from using this Gatherer is that, when dealing with a > Stream of events that you want to get metrics of, this gatherer is going to > be a critical tool in the arsenal. This Gatherer also pairs BEAUTIFULLY > with slidingWindow, to where I feel it made sliding window even stronger. I > break up my stream into chunks using the windowBy, then slide over those > chunks using sliding window. I kept finding myself using this strategy to > aggregate and analyze. To use an analogy, it feels almost like making a > database view of a larger database table. > > This is my experience using the windowBy Gatherer that Viktor Klang gave > me. Please let me know if there are any questions, comments, or concerns. > > Thank you for your time, patience, and understanding! > David Alayachew > > [1] = https://adventofcode.com/2020/day/14 > <https://urldefense.com/v3/__https://adventofcode.com/2020/day/14__;!!ACWV5N9M2RV99hQ!LEBjZbZKNTq2ifo9CYK0RE3c2wwJMxmUlb7ZWZ88j3Dgq50_x3z_2hX4j2GAL_hicf5s05xDzgM8__xH7_1j6kToUsc$> > [2] = > https://github.com/davidalayachew/Advent_of_Code/blob/1f054282d610af444dd27be4dfb374e10ac76db4/AOC/AOC_2020.java#L334 > <https://urldefense.com/v3/__https://github.com/davidalayachew/Advent_of_Code/blob/1f054282d610af444dd27be4dfb374e10ac76db4/AOC/AOC_2020.java*L334__;Iw!!ACWV5N9M2RV99hQ!LEBjZbZKNTq2ifo9CYK0RE3c2wwJMxmUlb7ZWZ88j3Dgq50_x3z_2hX4j2GAL_hicf5s05xDzgM8__xH7_1jakXmB9k$> > [3] = > https://github.com/davidalayachew/Advent_of_Code/blob/1f054282d610af444dd27be4dfb374e10ac76db4/AOC/AOC_2020.java#L468 > <https://urldefense.com/v3/__https://github.com/davidalayachew/Advent_of_Code/blob/1f054282d610af444dd27be4dfb374e10ac76db4/AOC/AOC_2020.java*L468__;Iw!!ACWV5N9M2RV99hQ!LEBjZbZKNTq2ifo9CYK0RE3c2wwJMxmUlb7ZWZ88j3Dgq50_x3z_2hX4j2GAL_hicf5s05xDzgM8__xH7_1jWHufk2U$> > [4] = https://github.com/davidalayachew/HowFastCanYouType > <https://urldefense.com/v3/__https://github.com/davidalayachew/HowFastCanYouType__;!!ACWV5N9M2RV99hQ!LEBjZbZKNTq2ifo9CYK0RE3c2wwJMxmUlb7ZWZ88j3Dgq50_x3z_2hX4j2GAL_hicf5s05xDzgM8__xH7_1jOKot3vY$> > [5] = > https://github.com/davidalayachew/HowFastCanYouType/blob/main/src/main/java/HowFastCanYouTypeModule/HowFastCanYouTypePackage/GUI.java#L151 > <https://urldefense.com/v3/__https://github.com/davidalayachew/HowFastCanYouType/blob/main/src/main/java/HowFastCanYouTypeModule/HowFastCanYouTypePackage/GUI.java*L151__;Iw!!ACWV5N9M2RV99hQ!LEBjZbZKNTq2ifo9CYK0RE3c2wwJMxmUlb7ZWZ88j3Dgq50_x3z_2hX4j2GAL_hicf5s05xDzgM8__xH7_1jXX46EYs$> >
