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

WEBVTT

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

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which has to be allocated

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and memory managed and freed again,

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which of course incurs an additional performance overhead.

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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

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from Emacs 30 onwards

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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

00:15:51.000 --> 00:15:56.799
to take advantage of this accelerated JSON parsing.

NOTE Native compilation

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Next up, another behind-the-scenes feature

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is that if you build Emacs on your own from source,

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you might know that if you wanted

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to use native compilation,

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so the translation of Elisp bytecodes

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to whatever the native assembly

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or native instruction set is on your system,

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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.

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The configure script will automatically check

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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

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or prefer not to use it for whatever reason,

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you now have to type --without-native-compilation

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when compiling Emacs to prevent this from happening.

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But native compilation was added in Emacs 28

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and has proven to be a very stable

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and useful feature for most people,

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so there's probably no reason to do this

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and you can just invoke the configure script

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with one argument less. Right, and I'd like to finish up

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with a few smaller features, a few smaller highlights.

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Maybe we can go back to the listing here. Here we have it.

NOTE Tree-sitter

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There are a few new major modes

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based on the tree-sitter library.

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tree-sitter is this parser library

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which has been integrated into Emacs 29.

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It allows the integration

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of external, specialized, and quick parsers into Emacs,

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which improve stuff like syntax highlighting, indentation,

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structural navigation, imenu support,

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by simply having a better understanding of, for example,

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a HTML file, or a Lua file, a PHP file,

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than what people usually implement

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using regular expressions in traditional major modes.

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So, a few new major modes which you can try out here.

NOTE Completion preview mode

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Another interesting feature is the completion-preview-mode.

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We can maybe try it out here in the scratch buffer.

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If I enable completion-preview-mode...

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This is a non-global minor mode,

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which will display completion options inline using overlays.

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For example, if I start typing a longer symbol like define,

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now we have a derived mode. It suggests me to...

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I can just press TAB and then it completes the option here,

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but it didn't actually...

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It's not actually modifying the buffer, it's not pressing,

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these are just overlays,

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so if I move around, it gets deleted.

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It wouldn't get saved if I were to save the buffer.

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The same also should work in a shell buffer.

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If I enable completion preview mode here and start...

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In this case, I'm using the bash completion package,

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which provides additional completion information.

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This is not only limited to programming systems,

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but anywhere where you have completion at point in Emacs.

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I can start typing here, ignore, and put ignore-backups,

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and it hints to the options which I have

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and allows me to complete them quickly.

NOTE package-isolate

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Another small feature is the package-isolate command.

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What this does is it will start

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or it will prompt me for packages

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I have installed in my system

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and will start an isolated

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or like "emacs -Q"-ish instance of emacs

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with only these packages installed.

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So for example, if I said I want slime and I want diff-hl,

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then this is a new Emacs window.

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It's unrelated to the one around.

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It uses the same executable, of course,

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but will not load your configuration file

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or any other further customizations on your system.

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All it does, it will ensure

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that these packages, which are listed here,

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so in our case SLIME and dependencies of SLIME and diff-hl,

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in the system

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so that I could, for example, as you can see here,

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diff-hl-mode works.

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Okay, this is not a version-controlled file.

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Maybe if we take a look at, have I enabled diff-hl-mode?

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It's enabled in this case. What diff-hl-mode does

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is it displays these version control changes

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in the fringe of a buffer.

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And even though this is a uncustomized version of Emacs,

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or an uncustomized instance of Emacs,

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it was easy for me to load this one package,

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or these two packages and all the dependencies necessary.

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As you can imagine, the main purpose for this

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is to make debugging issues easier.

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If you want to report about an issue

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you have with a package. And if I close this, it's closed

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and everything's thrown away.

NOTE Reindenting

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Last up, a nice feature I think

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a lot of people will appreciate is,

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if you are familiar with... Let's open a text buffer.

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The M-q key is traditionally bound to fill-paragraph.

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What this means is that...

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Let's, for example, copy this text from here

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and squash it all into one line. If I press M-q here,

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then the lines will be broken

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according to the fill column indicator up here.

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This is the traditional usage of M-q,

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and it still works in text-mode buffers,

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but in prog-mode buffers--

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so any major mode inheriting prog-mode--

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M-q will now by default be bound

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to prog-fill-reindent-defun. To summarize the point,

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if you are editing a string or a comment,

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then the comment will be filled.

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But if you are outside of a comment or outside of a string,

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then the defun or the top-level construct

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in the programming language will be re-indented.

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Let's try that out with maybe some file I have open here.

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If I'm in this... Let's choose some function,

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let's take this for example.

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If we followed all of this again,

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and I press M-q in on this paragraph,

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then the paragraph gets re-indented.

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But if I'm down here and I choose to break the indentation

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and then press M-q,

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then as you see, it practically selected the defun

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and re-indented everything

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without having me to move the point around in the buffer.

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So I think that's a really nice feature,

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which a lot of people can appreciate.

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It's one of those niceties which comes from time to time.

NOTE Wrapping up

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Right, so that was my overview

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of what's going to be new in Emacs 30.

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I hope that most people could take away

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something from this presentation

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and have something to look forward

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to try out after upgrading.

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As mentioned initially, as of recording,

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this release has not been completed yet.

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If this is still not the case

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when you're seeing this video,

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please consider downloading and building Emacs 30 yourself.

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If you have any issues, which is always the case,

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please report them to using report-emacs-bug.

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That will pop up a mail buffer,

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and then you can describe your issue and send them out.

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All bug reports are valuable,

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even if they are false positives or duplicates--

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it doesn't matter--

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because when you take the time to submit a bug report,

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which describes something that's specific to your setup,

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which the developers might not have noticed or known about,

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then you are certainly helping out a lot of other people

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which might run into the same issue in the future.

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Especially with upgrades,

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it would be nice to figure out small problems

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which make upgrading difficult for some people.

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The ideal is, of course, to have no issues

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when upgrading from one version to another.

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Having said that, I thank you for your attention,

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and I'm saying goodbye.