path: root/2024/captions/emacsconf-2024-emacs30--emacs-30-highlights--philip-kaludercic--main.vtt

WEBVTT captioned by anush and sachac, checked by anush and bhavin

NOTE Introduction

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Hello, and welcome to Emacs 30 Highlights at EmacsConf 2024.

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Before I begin, I'd like to thank the organizers

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and everyone involved for putting this all together.

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While this talk is being pre-recorded,

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my experience from the last few years

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assures me that it will be a great experience for everyone.

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My name is Philip Kaludercic.

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I am a core contributor and ELPA co-maintainer.

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I was honored when Sacha asked me

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to take over the slot for this year.

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In the past few iterations,

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John Wiegley has filled a similar presentation

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focusing on more general Emacs development updates.

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This year, I will specifically focus on

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highlight features from the upcoming Emacs 30 release,

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which might or might not have been released

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by the time you are seeing this.

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As you can imagine, everything new about Emacs

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can always be found in the Emacs NEWS file.

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Or, alternatively,

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if one doesn't want to read through the 3,000 lines here,

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one can also take a look at the Emacs FAQ

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and then go to the what's new about

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or what's different about Emacs 30 node.

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Next to these two official options,

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I also have a page on Emacs Wiki

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called EmacsThirtyHighlights,

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highlighting some of the interesting features

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with some context and suggestions on how to try them out.

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This is more of a collaborative effort.

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So if you see this and think something is missing,

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feel free to add it.

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So without further ado,

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let's begin taking a look at new features in Emacs 30.

NOTE Android

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The biggest one, and the one I want to mention first,

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is Android support, native Android support.

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As you can see here, Emacs has been ported

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to the Android operating system.

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What this means is that from Emacs 30 onwards,

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you can build Android to target Android devices natively

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and using a graphical interface.

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While it has been possible to run Emacs

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inside of terminal emulators on Android for a while,

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this actually means that you can use Emacs

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on an Android device, a phone or a tablet,

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and have all the usual advantages from GUI Emacs,

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such as the ability to bind all commands

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without having to worry about--

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all keys without having to worry

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about terminal compatibility issues,

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displaying images and multiple fonts

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on the same display of different sizes.

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I should have a recording

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of that somewhere here--here we are--

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which I made earlier on my phone,

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because I'm recording this on a laptop--

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where we can see how touch interaction works

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on an Android phone. I can switch between buffers.

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Here I've connected an external keyboard,

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opening the Emacs website.

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We have images that we can interact with.

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We could resize them if we wanted to

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with the image resizing commands.

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Pinch-to-zoom works, so it

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does realize what touchscreen interactions are.

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With an external mouse, and for example,

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enabling context menu mode,

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I can even pop up little interaction windows,

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which one you would usually also know from GUI Emacs.

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TUI Emacs actually also supports them since a while now.

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And in this case, I'm demonstrating

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how even the touchscreen events

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can be inspected using the usual help system,

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and how context-mode notices

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where we are and allows me to, for example,

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evaluate this specific region,

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which I've highlighted down there,

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binding a command to touch-screen-scroll. Yeah.

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One should note that these additions,

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for example touchscreen interaction,

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are not specific to Android,

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but they also are supported in other operating systems,

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such as Wayland and Xorg, which are not operating systems,

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and Windows, insofar as they have touchscreen,

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and devices have touchscreen support.

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One should mention, or I want to mention,

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that the main developer behind this feature, Po Lu,

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should be complimented for the additional effort he put

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into making sure that Emacs for Android

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can be built using only a free software toolchain,

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which is certainly not something one has come to expect

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from working on Android applications,

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as usually you have to agree to some terms and conditions

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for Google-specific software.

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Final note is that if you try and look for this online,

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there are APKs you can find,

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but some of them might be outdated.

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To the best of my knowledge, Po Lu has...

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Emacs 30 Android Sourceforge...

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He has set up some system where here in Sourceforge,

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there are regular and updated

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APK files which you can download

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to avoid having to build it yourself,

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testing out the newest version

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in case there are some bugs which you'd like to report.

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Which-key is a package which has now been moved

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from ELPA to the core.

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If you haven't heard of which-key before, the idea is,

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or the general pitch is that which-key

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is a additional documentation interface for Emacs

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for displaying various keys which you could input,

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or various keys and key maps

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that have been partially inputted.

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A better way to demonstrate this

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or to explain this is just to show it.

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If we enable the which-key mode--it's a global minor mode--

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then I can press, for example, C-x,

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which is a prefix for the C-x keymap.

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Then down here in the buffer, in this window down here,

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we see various commands which we could invoke

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and the keys to invoke them with.

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For example, if I wanted to say C-x i for insert-file,

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then I just have to press i to highlight it once again.

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It should be down here. Pressing i without having to repeat

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the entire key code again,

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the partial key code again, just works.

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This is different from the feature which Emacs has already,

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which is if you have input the partial keychord,

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you can press C-h

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and then a help buffer pops up with a listing

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of all keybindings that start with C-x.

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The information is the same, the presentation is different,

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because now if I wanted to do C-x i,

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I have to repeat the entire keychord again.

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So it's a matter of personal preference, which you prefer.

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This is more of a traditional static approach

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because I get a help buffer which I can search

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using usual key commands,

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while which-key is more of a transient and modern.

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Some might prefer that approach

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to solving the same problem.

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Also, don't forget to check out the customization group

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for which-key which has a number of options

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which you might or might not be interested in.

NOTE EditorConfig

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Next up, Emacs 30 has built-in EditorConfig support.

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If you have not heard of EditorConfig before,

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I believe I've linked to it down here somewhere.

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Ah, there it is, EditorConfig.

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This is a file format used to specify

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common formatting rules in an editor-agnostic way.

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You might compare it to .dir-locals.el files,

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which is a sort of an s-expression

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for setting file-local variables in Emacs.

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Of course, this is restricted to the common subset

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of what all editors should understand.

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For example, indentation styles,

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whether you prefer tabs or spaces,

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tab width, file encoding, and so on.

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So it's nothing too advanced, but it's something...

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It is a file format which one sees popping up more

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and more often in lots of projects

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which want to enforce a consistent indentation style

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or formatting rules for all editors in a project.

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Having this built in is certainly useful in Emacs.

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Though one should note that it's not enabled by default.

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You still have to enable the global minor mode,

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which is simply turning on this one option.

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Shouldn't be more than that,

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and then Emacs will respect the rules.

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If it finds a .editorconfig file in the project directory,

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then it will respect those rules

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without having to do anything else.

NOTE use-package integration with package-vc

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Next up, use-package integration with package-vc.

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For those not familiar with either of the two,

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or at least one of the two,

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use-package is a popular configuration macro.

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What it does is it allows

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users to declaratively specify packages

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they would like to have installed and configured

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in their configuration file,

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so that, for example, if you copy your init.el

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from one system to another,

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it could bootstrap the entire configuration,

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downloading all the packages you want

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without having to manually do this

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on every system you'd like to use.

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This allows configurations

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to be self-encapsulated and portable.

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package-vc is an extension of package.el,

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which allows installing packages from an alternative.

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Instead of using the standard way to install packages,

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which is just download tarball and unpack it,

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byte compile, and so on,

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it will fetch the files for a package

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directly from the source code repository

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and initialize it in such a way

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that package.el can work with it.

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So it's just a front-end for installing packages.

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Even though these two were added to Emacs 29,

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we didn't have the time to work on the

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use-package integration of package-vc into use-package,

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which has been changed now.

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What we have with Emacs 30 is that

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there is a :vc keyword for use-package

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with which we can instruct use-package

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to not download a package using tarball,

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but instead to fetch the source code

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from a source code repository.

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This is useful if you, for example,

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have packages which you yourself work on

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and know that you always want to have

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the development version of the package

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where you can directly commit changes you've made

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to the repository and push them upstream.

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Or, if you know that you want to contribute to a package,

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you can use package-vc to download the source code,

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have all the version control information,

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prepare a patch and send it upstream.

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In these examples here,

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the first example Lisp instructs package-vc

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to download the source code from a URL.

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So this is a git URL where it will download

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the source code from, and in this case,

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choose the newest checkout of the source code,

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not the latest release. Down here, we have another example.

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I prefer to consider the following example here.

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If we just had written this,

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then package-vc would use the metadata

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which an ELPA server provides

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to fetch the URL from the official repository of,

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in this case, BBDB, without having to...

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It would be more or less the same like this up here,

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with the simple difference that package-vc integration

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into use-package doesn't check out the latest commit,

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but the latest release,

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just to keep configurations more deterministic by default.

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Of course, if you prefer to use latest commit,

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you can use a package-vc install command

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or just update the package manually yourself,

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which you can use using package-vc-upgrade.

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Next, I'd like to focus on a few features

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which one might not necessarily realize directly,

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but will hopefully improve your experience with Emacs.

NOTE JSON

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First up in this list is a new JSON parser.

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Let's maybe show the source code for that one:

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not json.el, json.c. The history of JSON parsing in Emacs

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started with Emacs 23 with the addition of json.el.

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This was the file which we had just opened a moment ago.

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This is a JSON parser in Emacs Lisp.

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It's fine, it does the job, but it can get slow

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if we have a situation like where

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Eglot uses a LSP server to communicate with

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and the LSP server can get a bit chatty,

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sending a lot of JSON data,

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which all has to be parsed and garbage collected,

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which can slow down Emacs a bit.

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The situation was improved upon in Emacs 29

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when JSON parsing was added to the core.

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This was the json.c file, which we see on this side,

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the old version of the json.c file,

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which employed the Jansson library (it's the C library)

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for parsing and accelerating JSON parsing in Emacs.

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This was good enough,

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or it certainly improved the situation

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for a lot of LSP clients.

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But in Emacs 30, the situation has been improved once more

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with the addition of a JSON parser directly in Emacs.

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So instead of using an external library,

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there's a custom JSON parser written in C in the Emacs core,

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which directly generates Elisp objects.

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The advantage to this approach

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compared to the Jansson approach

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is that there's no intermediate format

00:15:07.966 --> 00:15:09.200
which has to be allocated

00:15:09.233 --> 00:15:11.500
and memory managed and freed again,

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which of course incurs an additional performance overhead.

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Next to this, there's also a custom serializer

00:15:22.466 --> 00:15:29.239
for JSON contents translating a JSON object into a string.

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... The consequence of this is that

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there is absolutely no dependency on Jansson anymore.

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This in turn means that now all Emacs users

00:15:38.566 --> 00:15:39.800
from Emacs 30 onwards

00:15:39.833 --> 00:15:42.733
can take advantage of this new JSON parser

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and don't have to worry about whether

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or not they have Jansson, this JSON parsing library,

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installed on their system or not when they want

00:15:50.466 --> 00:15:56.679
to take advantage of this accelerated JSON parsing.

NOTE Native compilation

00:15:56.680 --> 00:16:00.366
Next up, another behind-the-scenes feature

00:16:00.400 --> 00:16:06.406
is that if you build Emacs on your own from source,

00:16:06.407 --> 00:16:07.766
you might know that if you wanted

00:16:07.800 --> 00:16:09.533
to use native compilation,

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so the translation of Elisp bytecodes

00:16:12.380 --> 00:16:15.533
to whatever the native assembly

00:16:15.566 --> 00:16:19.133
or native instruction set is on your system,

00:16:19.166 --> 00:16:24.339
you have to specify with native compilation.

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when invoking the configure script,

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otherwise it would not have been enabled at all.

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With Emacs 30, this step is not necessary anymore.

00:16:32.480 --> 00:16:36.233
The configure script will automatically check

00:16:36.266 --> 00:16:41.700
if you have the libgccjit library installed on your system,

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and if that is so,

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then native compilation will be enabled by default.

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In other words, if you have an issue with native compilation

00:16:49.433 --> 00:16:52.500
or prefer not to use it for whatever reason,

00:16:52.500 --> 00:16:55.533
you now have to type --without-native-compilation

00:16:55.566 --> 00:16:58.433
when compiling Emacs to prevent this from happening.

00:16:58.466 --> 00:17:02.433
But native compilation was added in Emacs 28

00:17:02.466 --> 00:17:04.333
and has proven to be a very stable

00:17:04.366 --> 00:17:06.233
and useful feature for most people,

00:17:06.266 --> 00:17:09.400
so there's probably no reason to do this

00:17:09.433 --> 00:17:11.133
and you can just invoke the configure script

00:17:11.166 --> 00:17:16.300
with one argument less. Right, and I'd like to finish up

00:17:16.300 --> 00:17:19.500
with a few smaller features, a few smaller highlights.

00:17:19.500 --> 00:17:29.639
Maybe we can go back to the listing here. Here we have it.

NOTE Tree-sitter

00:17:29.640 --> 00:17:32.833
There are a few new major modes

00:17:32.866 --> 00:17:34.333
based on the tree-sitter library.

00:17:34.366 --> 00:17:37.939
tree-sitter is this parser library

00:17:37.940 --> 00:17:39.933
which has been integrated into Emacs 29.

00:17:39.966 --> 00:17:44.100
It allows the integration

00:17:44.100 --> 00:17:48.400
of external, specialized, and quick parsers into Emacs,

00:17:48.433 --> 00:17:52.133
which improve stuff like syntax highlighting, indentation,

00:17:52.166 --> 00:17:55.233
structural navigation, imenu support,

00:17:55.266 --> 00:18:01.033
by simply having a better understanding of, for example,

00:18:01.066 --> 00:18:03.900
a HTML file, or a Lua file, a PHP file,

00:18:03.900 --> 00:18:06.233
than what people usually implement

00:18:06.266 --> 00:18:10.366
using regular expressions in traditional major modes.

00:18:10.400 --> 00:18:16.779
So, a few new major modes which you can try out here.

NOTE Completion preview mode

00:18:16.780 --> 00:18:20.033
Another interesting feature is the completion-preview-mode.

00:18:20.066 --> 00:18:22.966
We can maybe try it out here in the scratch buffer.

00:18:23.000 --> 00:18:28.300
If I enable completion-preview-mode...

00:18:28.300 --> 00:18:32.033
This is a non-global minor mode,

00:18:32.066 --> 00:18:38.600
which will display completion options inline using overlays.

00:18:38.633 --> 00:18:43.133
For example, if I start typing a longer symbol like define,

00:18:43.166 --> 00:18:48.200
now we have a derived mode. It suggests me to...

00:18:48.233 --> 00:18:51.133
I can just press TAB and then it completes the option here,

00:18:51.166 --> 00:18:51.933
but it didn't actually...

00:18:51.966 --> 00:18:55.333
It's not actually modifying the buffer, it's not pressing,

00:18:55.366 --> 00:18:57.100
these are just overlays,

00:18:57.100 --> 00:18:59.533
so if I move around, it gets deleted.

00:18:59.566 --> 00:19:02.619
It wouldn't get saved if I were to save the buffer.

00:19:02.620 --> 00:19:04.966
The same also should work in a shell buffer.

00:19:05.000 --> 00:19:08.366
If I enable completion preview mode here and start...

00:19:08.400 --> 00:19:12.800
In this case, I'm using the bash completion package,

00:19:12.833 --> 00:19:15.000
which provides additional completion information.

00:19:15.033 --> 00:19:17.933
This is not only limited to programming systems,

00:19:17.966 --> 00:19:22.900
but anywhere where you have completion at point in Emacs.

00:19:22.900 --> 00:19:26.159
I can start typing here, ignore, and put ignore-backups,

00:19:26.160 --> 00:19:30.000
and it hints to the options which I have

00:19:30.033 --> 00:19:34.200
and allows me to complete them quickly.

NOTE package-isolate

00:19:34.233 --> 00:19:37.966
Another small feature is the package-isolate command.

00:19:38.000 --> 00:19:40.000
What this does is it will start

00:19:40.033 --> 00:19:42.800
or it will prompt me for packages

00:19:42.833 --> 00:19:44.333
I have installed in my system

00:19:44.366 --> 00:19:46.500
and will start an isolated

00:19:46.500 --> 00:19:51.133
or like "emacs -Q"-ish instance of emacs

00:19:51.166 --> 00:19:53.333
with only these packages installed.

00:19:53.366 --> 00:20:00.439
So for example, if I said I want slime and I want diff-hl,

00:20:00.440 --> 00:20:02.700
then this is a new Emacs window.

00:20:02.700 --> 00:20:04.533
It's unrelated to the one around.

00:20:04.566 --> 00:20:06.500
It uses the same executable, of course,

00:20:06.500 --> 00:20:09.939
but will not load your configuration file

00:20:09.940 --> 00:20:13.679
or any other further customizations on your system.

00:20:13.680 --> 00:20:15.533
All it does, it will ensure

00:20:15.566 --> 00:20:17.933
that these packages, which are listed here,

00:20:17.966 --> 00:20:24.599
so in our case SLIME and dependencies of SLIME and diff-hl,

00:20:24.600 --> 00:20:25.300
in the system

00:20:25.300 --> 00:20:29.100
so that I could, for example, as you can see here,

00:20:29.100 --> 00:20:32.139
diff-hl-mode works.

00:20:32.140 --> 00:20:34.766
Okay, this is not a version-controlled file.

00:20:34.800 --> 00:20:41.200
Maybe if we take a look at, have I enabled diff-hl-mode?

00:20:41.233 --> 00:20:44.600
It's enabled in this case. What diff-hl-mode does

00:20:44.633 --> 00:20:48.300
is it displays these version control changes

00:20:48.300 --> 00:20:49.566
in the fringe of a buffer.

00:20:49.600 --> 00:20:54.133
And even though this is a uncustomized version of Emacs,

00:20:54.166 --> 00:20:56.333
or an uncustomized instance of Emacs,

00:20:56.366 --> 00:20:59.000
it was easy for me to load this one package,

00:20:59.033 --> 00:21:02.033
or these two packages and all the dependencies necessary.

00:21:02.066 --> 00:21:05.300
As you can imagine, the main purpose for this

00:21:05.300 --> 00:21:07.733
is to make debugging issues easier.

00:21:07.766 --> 00:21:10.566
If you want to report about an issue

00:21:10.600 --> 00:21:14.900
you have with a package. And if I close this, it's closed

00:21:14.900 --> 00:21:16.919
and everything's thrown away.

NOTE Reindenting

00:21:16.920 --> 00:21:19.000
Last up, a nice feature I think

00:21:19.033 --> 00:21:20.933
a lot of people will appreciate is,

00:21:20.966 --> 00:21:24.300
if you are familiar with... Let's open a text buffer.

00:21:24.300 --> 00:21:30.279
The M-q key is traditionally bound to fill-paragraph.

00:21:30.280 --> 00:21:32.200
What this means is that...

00:21:32.233 --> 00:21:35.000
Let's, for example, copy this text from here

00:21:35.033 --> 00:21:40.366
and squash it all into one line. If I press M-q here,

00:21:40.400 --> 00:21:42.719
then the lines will be broken

00:21:42.720 --> 00:21:49.879
according to the fill column indicator up here.

00:21:49.880 --> 00:21:52.600
This is the traditional usage of M-q,

00:21:52.633 --> 00:21:54.200
and it still works in text-mode buffers,

00:21:54.233 --> 00:21:55.859
but in prog-mode buffers--

00:21:55.860 --> 00:22:00.100
so any major mode inheriting prog-mode--

00:22:00.100 --> 00:22:02.233
M-q will now by default be bound

00:22:02.266 --> 00:22:09.779
to prog-fill-reindent-defun. To summarize the point,

00:22:09.780 --> 00:22:13.433
if you are editing a string or a comment,

00:22:13.466 --> 00:22:16.039
then the comment will be filled.

00:22:16.040 --> 00:22:19.100
But if you are outside of a comment or outside of a string,

00:22:19.100 --> 00:22:23.166
then the defun or the top-level construct

00:22:23.200 --> 00:22:26.159
in the programming language will be re-indented.

00:22:26.160 --> 00:22:34.099
Let's try that out with maybe some file I have open here.

00:22:34.100 --> 00:22:38.800
If I'm in this... Let's choose some function,

00:22:38.833 --> 00:22:40.733
let's take this for example.

00:22:40.766 --> 00:22:43.959
If we followed all of this again,

00:22:43.960 --> 00:22:47.400
and I press M-q in on this paragraph,

00:22:47.433 --> 00:22:49.433
then the paragraph gets re-indented.

00:22:49.466 --> 00:22:55.800
But if I'm down here and I choose to break the indentation

00:22:55.833 --> 00:22:58.166
and then press M-q,

00:22:58.200 --> 00:23:02.333
then as you see, it practically selected the defun

00:23:02.366 --> 00:23:03.566
and re-indented everything

00:23:03.600 --> 00:23:06.959
without having me to move the point around in the buffer.

00:23:06.960 --> 00:23:08.633
So I think that's a really nice feature,

00:23:08.666 --> 00:23:11.100
which a lot of people can appreciate.

00:23:11.100 --> 00:23:17.939
It's one of those niceties which comes from time to time.

NOTE Wrapping up

00:23:17.940 --> 00:23:20.633
Right, so that was my overview

00:23:20.666 --> 00:23:22.600
of what's going to be new in Emacs 30.

00:23:22.633 --> 00:23:24.400
I hope that most people could take away

00:23:24.433 --> 00:23:25.579
something from this presentation

00:23:25.580 --> 00:23:28.900
and have something to look forward

00:23:28.900 --> 00:23:31.133
to try out after upgrading.

00:23:31.166 --> 00:23:33.833
As mentioned initially, as of recording,

00:23:33.866 --> 00:23:36.566
this release has not been completed yet.

00:23:36.600 --> 00:23:38.833
If this is still not the case

00:23:38.866 --> 00:23:40.233
when you're seeing this video,

00:23:40.266 --> 00:23:43.833
please consider downloading and building Emacs 30 yourself.

00:23:43.866 --> 00:23:48.200
If you have any issues, which is always the case,

00:23:48.233 --> 00:23:56.439
please report them to using report-emacs-bug.

00:23:56.440 --> 00:23:57.907
That will pop up a mail buffer,

00:23:57.908 --> 00:23:59.600
and then you can describe your issue and send them out.

00:23:59.633 --> 00:24:01.800
All bug reports are valuable,

00:24:01.833 --> 00:24:04.433
even if they are false positives or duplicates--

00:24:04.466 --> 00:24:05.233
it doesn't matter--

00:24:05.266 --> 00:24:08.533
because when you take the time to submit a bug report,

00:24:08.566 --> 00:24:12.233
which describes something that's specific to your setup,

00:24:12.266 --> 00:24:16.700
which the developers might not have noticed or known about,

00:24:16.700 --> 00:24:19.133
then you are certainly helping out a lot of other people

00:24:19.166 --> 00:24:21.766
which might run into the same issue in the future.

00:24:21.800 --> 00:24:23.200
Especially with upgrades,

00:24:23.233 --> 00:24:26.566
it would be nice to figure out small problems

00:24:26.600 --> 00:24:30.800
which make upgrading difficult for some people.

00:24:30.833 --> 00:24:34.700
The ideal is, of course, to have no issues

00:24:34.700 --> 00:24:37.199
when upgrading from one version to another.

00:24:37.200 --> 00:24:39.566
Having said that, I thank you for your attention,

00:24:39.600 --> 00:24:43.766
and I'm saying goodbye.