Full Width [alt+shift+f] Shortcuts [alt+shift+k]
Sign Up [alt+shift+s] Log In [alt+shift+l]
25
Recently, I completed the GitHub Game Off. With over 500 entries, this is the largest game jam I’ve been a part of. I had some lofty goals for this game, and I just about met them all. I’m extremely happy with how the game came out! Like prior games I’ve made, I don’t tend to join a game jam unless I have some specific idea/mechanic I’d like to explore. I’d been wanting to tackle a mobile game for some time now while exploring motion/accelerometer mechanics. Mechanics The theme for this jam was “bug”. I don’t remember how I arrived at the concept and gameplay, but the gist is: a fly mysteriously gets sucked into a phone. By tilting your phone (utilizing the phone’s motion/accelerometer sensors), you move the fly to avoid colliding with objects on the phone’s screen. Tilting your phone at steeper angles increases the fly’s velocity and speed. While relatively basic, I found it challenging to get the mechanics just right, and reprogrammed this mechanic several times. The game consists of...
over a year ago

Improve your reading experience

Logged in users get linked directly to articles resulting in a better reading experience. Please login for free, it takes less than 1 minute.

More from Daniel Marino

Making an Escape Room with only HTML and CSS

Beware! This post includes spoilers! I recently built an escape room game called CSScape Room. This isn’t my first JavaScript-free web game, but HTML and CSS have evolved significantly since my previous attempts, with newer additions allowing for more complex selectors and native interactions. Rather than saving this idea for a game jam, I built it purely for fun, which freed me from theme constraints and time pressure. I’ve enjoyed escape room games since childhood, and it was nostalgic to recreate that experience myself. This project pushed my artistic limits while challenging me to design puzzles and translate them into complex HTML and CSS. The learning process was fun, challenging, and sometimes tedious—mostly through trial and error. Process My creative process isn’t linear—it’s a blend of designing, puzzle creation, and coding that constantly influences each other. I frequently had to redesign or recode elements as the project evolved. There was also that time I accidentally deleted half my CSS because I wasn’t backing up to GitHub... lesson learned! 😬 This might sound chaotic, and honestly, it was. If you’re wondering where to start with a project like this, I began by prototyping the room navigation system. I figured that was the minimum viable feature—if I couldn’t make that work, I’d abandon the project. The solution I eventually found seems simple in retrospect, but I went through several iterations to discover it. This flexible approach makes sense for my creative projects. As I build something, both the in-progress work and my growing skills inevitably influences the entire project. I’m comfortable with this non-linear process—it also suits my ADHD brain, where I tend to lose interest if I work on the same thing for too long. Artwork I’d wanted to design a pixel art-styled game for some time but never felt confident enough to attempt it during a game jam because of the learning curve. I watched tutorials from Adam Yunis and Mort to get a crash course in pixel art best practices. Initially, progress was slow. I had to figure out 2D perspective with vanishing points, determine a color palette, practice shading techniques, and decide how much detail to include. While I tried to adhere to pixel art “rules,” I definitely broke some along the way. One challenge I set for myself was using only 32 colors to capture the feeling of an older gaming console. Once I got comfortable with shading and dithering, working within this constraint became easier. An added benefit to using 32 colors was it resulted in smaller image sizes—the game’s 79 images account for only about 25% of the total payload. I attempted to design sprites using dimensions in multiples of eight, but I’ll admit I became less strict about this as the project progressed. At a certain point, I was struggling enough with the color and styling limitations that this guideline became more of a starting point than a rule. I considered creating my own font, but after exhausting myself with all the artwork, I opted for Google’s PixelifySans instead. Almost all animation frames were individually drawn (except for the “one” TV animation). This was tedious, but I was determined to stay true to old-school techniques! I did use CSS to streamline some animations—for instance, I used animation-direction: alternate on the poster page curl to create a palindrome effect, halving the number of required sprites. Mechanics Like my previous game Heiro, this project primarily uses checkbox and radio button mechanics. However, the addition of the :has() pseudo-selector opened up many more possibilities. I also utilized the popover API to create more detailed interactions. Checkbox and Radio Selection Triggering interactions by toggling checkboxes and radio buttons isn’t new, but the :has() selector is a game-changer! Before this existed, you had to structure your markup so interactive elements were siblings. The :has() selector makes this far more flexible because you no longer need to rely on a specific HTML structure. #element { display: none; } :has(#checkbox:checked) #element { display: block; } Using this pattern, :has() looks for #checkbox anywhere on the page, meaning you don’t have to rely on #checkbox, its corresponding <label>, or #element being siblings. The markup structure is no longer a constraint. Most of this game functions on toggling checkboxes and radios to unlock, collect, and use items. Navigation I almost gave up on the current implementation, and used basic compass notation to avoid visual transitions between directions. After several failed attempts, I found a solution. The tricky part was determining how to transition into a direction from either left or right, depending on which arrow was clicked. My solution is conceptually simple but difficult to explain! First, I used radio buttons to determine which direction you’re facing (since you can only face one direction at a time). Second, I needed a way to determine if you’re entering a direction from west or east. This required eight radio buttons—two for each direction. For example, if you’re facing east (having come from facing north), you have two possible directions to go: west (returning to face north) or east (to face south). I needed to make the radio buttons visible that would take you north from east, and south from west. The CSS looks something like this: :has(#east-from-west:checked) :is( [for="south-from-west"], [for="north-from-east"]) { display: block; } This pattern was implemented for each direction, along with animations to ensure each room view slid in and out correctly. Zooming In I initially focused so much on checkbox mechanics that I assumed I’d need the same approach for zooming in on specific areas. Then I had a "Duh!" moment and realized the popover API would be perfect. Here’s the basic markup for looking at an individual book: <button popovertarget="book">Zoom in</button> <div id="book" popover> <!-- Book content goes here --> <button popovertarget="book" popovertargetaction="hide">Close</button> </div> Turning the Lights Off I procrastinated on implementing this feature because I thought I’d need to create darkened variations of all artwork. I don’t recall what inspired me to try blend modes, but I’m glad I did—the solution was surprisingly simple. When the light switch checkbox is toggled, a <div> becomes visible with a dark background color and mix-blend-mode: multiply. This multiplies the colors of the blending and base layers, resulting in a darker appearance. Playing the Crossword This required surprisingly complex CSS. Each square has three letters plus a blank tile, meaning four radio buttons. The :checked letter has a z-index of 3 to display above other letters, but also has pointer-events: none so clicks pass through to the next letter underneath (with z-index: 2). The remaining tiles have a z-index of 1. The CSS becomes even trickier when the last tile is :checked, requiring some creative selector gymnastics to target the first radio button in the stack again. Tools I created all artwork using Aseprite, which is specifically designed for pixel art. I probably only used a fraction of its features, and I’m not sure it actually made my life easier—it might have made things more difficult at times. I’m not giving up on it yet, though. I suspect I’ll occasionally discover features that make me think, “Oh, that’s way easier than what I was doing!” I started coding with basic HTML and CSS but eventually found navigation difficult with such a long HTML file. It also became tedious writing the same attributes for every <img /> element. I migrated the project to Eleventy to improve organization and create custom shortcodes for simplifying component creation. I used the html-minifier-terser npm package, which integrates well with Eleventy. I chose native CSS over Sass for several reasons: CSS now has native nesting for better organization and leaner code CSS has built-in variables HTTP/2 handles asset loading efficiently, eliminating the major benefit of bundling CSS files The game uses 12 CSS files with 12 <link rel="stylesheet" /> tags. The only Sass feature I missed was the ability to loop through style patterns for easier maintenance, but this wasn’t a significant issue. The game is hosted on GitHub Pages. During deployment, it runs an npm command to minify CSS using Lightning CSS. I mentioned accidentally deleting half my CSS earlier—this happened because I initially used Eleventy’s recommended approach with the clean-css npm package. I strongly advise against using this! This package doesn’t work with native CSS nesting. While losing code was frustrating, I rewrote much of it more efficiently, so there was a silver lining. Nice to Haves I initially wanted to make this game fully accessible, but the navigation system doesn’t translate well for screen reader users. I tried implementing a more compass-like navigation approach for keyboard users, but it proved unreliable and conflicted with the side-to-side approach. Adding text labels for interactive elements was challenging because you can’t track the :focus state of a <label> element. While you can track the :focus of the corresponding <input />, it wasn’t consistently reliable. The main keyboard accessibility issue is that the game exists as one long HTML page. When you navigate to face a different direction, keyboard focus remains elsewhere on the page, requiring extensive tabbing to reach navigation elements or item selection. I ultimately decided to make the game deliberately inaccessible by adding tabindex="-1" to all keyboard-accessible elements. I’d rather users recognize immediately that they can’t play with assistive technology than become frustrated with a partially broken experience. Sound would have been a nice addition, but I encountered the same issues as with my previous game Heiro. You can toggle the visibility of an <embed> element, but once it’s visible, you can’t hide it again—meaning there’s no way to toggle sound on and off. Conclusion CSScape Room was a fun but exhausting four-month project. It began as an experiment to see if creating a JavaScript-free escape room was possible—and the answer is definitely yes. I’ve only touched on some aspects here, so if you’re interested in the technical details, check out the source code on GitHub. Finally, I’d like to thank all my playtesters for their valuable feedback!

3 months ago 50 votes
Self-avoiding Walk

I’m a bit late to this, but back in summer 2024 I participated in the OST Composing Jam. The goal of this jam is to compose an original soundtrack (minimum of 3 minutes) of any style for an imaginary game. While I’ve composed a lot of video game music, I’ve never created an entire soundtrack around a single concept. Self Avoiding Walk by Daniel Marino To be honest, I wasn’t entirely sure where to start. I was torn between trying to come up with a story for a game to inspire the music, and just messing around with some synths and noodling on the keyboard. I did a little bit of both, but nothing really materialized. Synth + Metal ≈ Synthmetal Feeling a bit paralyzed, I fired up the ’ole RMG sequencer for inspiration. I saved a handful of randomized melodies and experimented with them in Reaper. After a day or two I landed on something I liked which was about the first 30 seconds or so of the second track: "Defrag." I love metal bands like Tesseract, Periphery, The Algorithm, Car Bomb, and Meshuggah. I tried experimenting with incorporating syncopated guttural guitar sounds with the synths. After several more days I finished "Defrag"—which also included "Kernel Panic" before splitting that into its own track. I didn’t have a clue what to do next, nor did I have a concept. Composing the rest of the music was a bit of a blur because I bounced around from song to song—iterating on the leitmotif over and over with different synths, envelopes, time signatures, rhythmic displacement, pitch shifting, and tweaking underlying chord structures. Production The guitars were recorded using DI with my Fender Squire and Behringer Interface. I’m primarily using the ML Sound Labs Amped Roots Free amp sim because the metal presets are fantastic and rarely need much fuss to get it sounding good. I also used Blue Cat Audio free amp sim for clean guitars. All the other instruments were MIDI tracks either programmed via piano roll or recorded with my Arturia MiniLab MKII. I used a variety of synth effects from my library of VSTs. I recorded this music before acquiring my Fender Squire Bass guitar, so bass was also programmed. Theme and Story At some point I had five songs that all sounded like they could be from the same game. The theme for this particular jam was "Inside my world." I had to figure out how I could write a story that corresponded with the theme and could align with the songs. I somehow landed on the idea of the main actor realizing his addiction to AI, embarking on a journey to "unplug." The music reflects his path to recovery, capturing the emotional and psychological evolution as he seeks to overcome his dependency. After figuring this out, I thought it would be cool to name all the songs using computer terms that could be metaphors for the different stages of recovery. Track listing Worm – In this dark and haunting opening track, the actor grapples with his addiction to AI, realizing he can no longer think independently. Defrag – This energetic track captures the physical and emotional struggles of the early stages of recovery. Kernel Panic – Menacing and eerie, this track portrays the actor’s anxiety and panic attacks as he teeters on the brink during the initial phases of recovery. Dæmons – With initial healing achieved, the real challenge begins. The ominous and chaotic melodies reflect the emotional turbulence the character endures. Time to Live – The actor, having come to terms with himself, experiences emotional growth. The heroic climax symbolizes the realization that recovery is a lifelong journey. Album art At the time I was messing around with Self-avoiding walks in generative artwork explorations. I felt like the whole concept of avoiding the self within the context of addiction and recovery metaphorically worked. So I tweaked some algorithms and generated the self-avoiding walk using JavaScript and the P5.js library. I then layered the self-avoiding walk over a photo I found visually interesting on Unsplash using a CSS blend mode. Jam results I placed around the top 50% out of over 600 entries. I would have liked to have placed higher, but despite my ranking, I thoroughly enjoyed composing the music! I’m very happy with the music, its production quality, and I also learned a lot. I would certainly participate in this style of composition jam again!

3 months ago 31 votes
What I’m Using in 2025

I’ve always been fascinated to see what other apps or workflows others are using in their day-to-day lives. Every now and then I learn about a new app or some cool trick I didn’t previously know. I doubt anyone seriously cares about what I’m using, but figured I’d list them out anyway—if for no other reason than to keep a historical record at this point in time. Applications Alfred — I have a lifelong license, and I like it. No point in fixing something that isn’t broken. I primarily use it for app switching, but also use it for math, and to search for gifs. Aseprite — Sometimes I do pixel art! Even if the UI is clunky, and some keyboard shortcuts aren’t always convenient, there are some unique features that help facilitate creating pixel art. Audacity — I rarely use it, but sometimes it’s easier to make some quick audio edits with Audacity than to use a full blown DAW. Bear — This is the note-taking, task-tacking app I’ve landed on. The UI is beautiful and it feels snappy. It syncs, so I can use it on my iPhone too. Chrome — I used Arc for the better part of 2024, but after they announced they were done working on it to focus on a new AI-powered browser, I peaced out. There are a couple of features I really missed, but was able to find some extensions to fill those gaps: Copy Current Tab URL, Meetings Page Auto Closer for Zoom, Open Figma app, and JSON Formatter. Figma — I use it because it’s what we use at work. I’m happy enough with Figma. iTerm2 — Has a few features that I like that makes me chose this over Mac’s native Terminal app. Pixelmator Pro — I haven’t paid the Adobe tax for a long time, and it feels good. I started using Pixelmator because at the time it was the best alternative available. I’m comfortable with Pixelmator at this point. I don’t really use image editors often these days, so I probably won’t switch anytime soon. Reaper — My DAW of choice when composing music. It’s very customizable, easyish enough to learn, and the price is right. It also has a die hard community, so I’m always able to find help when I need it. VS Code — I’ve tried a lot of code editors. I prefer Sublime’s UI over VS Code, but VS Code does a lot of things more easily than Sublime does, so I put up with the UI. YouTube Music — I still miss Rdio. YouTube Music works well enough I guess. Paying for YouTube Music has the benefit of not seeing ads on YouTube. Command-line Tools These aren’t apps per se, but these are some tools that I use to help manage packages or that I use regularly when developing. Deno Eleventy Homebrew pure statikk Vite Volta yt-dlp Equipment I have one computer and I use it for everything, and I’m okay with that. It’s more than powerful enough for work, composing music, making games, and occasionaly playing games. Although I have a dedicated home office, lately I tend to work more on the go, often with just my laptop—whether that’s at a cafe, a coworking space, or even just moving around the house. 2021 M1 MacBook Pro AKG K240 Studio Headphones Arturia MiniLab MKII Controller Behringer UMC202HD USB Audio Interface Fender Squire Strat Guitar Fender Squire Bass Guitar Shure SM57 Virtual Instruments This is quite specific for composing music, so if that does’t interest you, feel free to stop reading here. This list is not exhaustive as I’m regularly trying out new VSTs. These are some staples that I use: 🎹 Arturia Analog Lab V (Intro) — My Arturia controller came with this software. It has over 500 presets and I love exploring the variety of sounds. 🎸 Bass Grinder (Free) — I recently came across this VST, and it has a great crunchy overdrive sound for bass guitar. 🥁 Manda Audio Power Drum Kit — Even though you can use this for free, I paid the $9 because it is fantastic. The drums sound real and are great for all styles of music. 🎸 ML Amped Roots (Free) — What I like about this is that I get great metal guitar out of the bost without having to add pedals or chaining other effects. 🥁 ML Drums (Free) — I just started experimenting with this, and the drum tones are amazing. The free set up is pretty limited, but I like how I can add on to the base drum kit to meet my needs rather than having having to buy one big extensive drum VST. 🎹 Spitfire LABS — More variety of eclectic sounds. I also use several built-in VSTs made by Reaper for delay, EQ, reverb, pitch-shifting, and other effects. Reaper’s VSTs are insanely powerful enough for my needs and are much less CPU intensive.

5 months ago 65 votes
Daily Inspirational Word

Over the past couple of years I’ve gotten into journaling. Recently I’ve been using a method where you’re given a single inspirational word as a prompt, and go from there. Unfortunately, the process of finding, saving, and accessing inspirational words was a bit of a chore: Google a list of “366 inspirational words”. Get taken to a blog bloated with ads and useless content all in an effort to generate SEO cred. Copy/paste the words into Notion. Fix how the words get formatted becasue Notion is weird, and I have OCD about formatting text. While this gets the job done, I felt like there was room to make this a more pleasant experience. All I really wanted was a small website that serves a single inspirational word on a daily basis without cruft or ads. This would allow me to get the content I want without having to scroll through a long list. I also don't want to manage or store the list of words. Once I've curated a list of words, I want to be done with it. Creating a microsite I love a good microsite, and so I decided to create one that takes all the chore out of obtaining a daily inspirational word. The website is built with all vanilla tech, and doesn’t use any frameworks! It’s nice and lean, and it’s footprint is only 6.5kb. Inspirational words While I’m not a huge fan of AI, I did leverage ChatGPT on obtaining 366 inspirational words. The benefit to ChatGPT was being able to get it to return the words as an array—cutting down on the tedium of having to convert the words I already had into an array. The words are stored in it’s own JSON file, and I use an async/await function to pull in the words, and then process the data upon return. Worth the effort I find these little projects fun and exciting because the scope is super tight, and makes for a great opportunity to learn new things. It’s definitely an overengineered solution to my problem, but it is a much more pleasant experience. And perhaps it will serve other people as well.

a year ago 104 votes
Daily Inspirational Word

Over the past couple of years I’ve gotten into journaling. Recently I’ve been using a method where you’re given a single inspirational word as a prompt, and go from there. Unfortunately, the process of finding, saving, and accessing inspirational words was a bit of a chore: 1. Google a list of “366 inspirational words”. 2. Get taken to a blog bloated with ads and useless content all in an effort to generate SEO cred. 3. Copy/paste the words into Notion. 4. Fix how the words get formatted becasue Notion is weird, and I have OCD about formatting text. While this gets the job done, I felt like there was room to make this a more pleasant experience. All I really wanted was a small website that serves a single inspirational word on a daily basis without cruft or ads. This would allow me to get the content I want without having to scroll through a long list. I also don't want to manage or store the list of words. Once I've curated a list of words, I want to be done with it. ## Creating a microsite I love a good microsite, and so I decided to create one that takes all the chore out of obtaining a [daily inspirational word](https://starzonmyarmz.github.io/daily-inspirational-word/). ![Daily Inspirational Word screenshot](/images/posts/daily_inspirational_word.jpeg) The website is built with all vanilla tech, and doesn’t use any frameworks! It’s nice and lean, and it’s footprint is only 6.5kb. ### Inspirational words While I’m not a huge fan of AI, I did leverage ChatGPT on obtaining 366 inspirational words. The benefit to ChatGPT was being able to get it to return the words as an array—cutting down on the tedium of having to convert the words I already had into an array. The words are stored in it’s own JSON file, and I use an async/await function to pull in the words, and then process the data upon return. ## Worth the effort I find these little projects fun and exciting because the scope is super tight, and makes for a great opportunity to learn new things. It’s definitely an overengineered solution to my problem, but it is a much more pleasant experience. And perhaps it will serve other people as well.

a year ago 37 votes

More in programming

Another tip (tip)
16 hours ago 3 votes
Get in losers, we're moving to Linux!

I've never seen so many developers curious about leaving the Mac and giving Linux a go. Something has really changed in the last few years. Maybe Linux just got better? Maybe powerful mini PCs made it easier? Maybe Apple just fumbled their relationship with developers one too many times? Maybe it's all of it. But whatever the reason, the vibe shift is noticeable. This is why the future is so hard to predict! People have been joking about "The Year of Linux on the Desktop" since the late 90s. Just like self-driving cars were supposed to be a thing back in 2017. And now, in the year of our Lord 2025, it seems like we're getting both! I also wouldn't underestimate the cultural influence of a few key people. PewDiePie sharing his journey into Arch and Hyprland with his 110 million followers is important. ThePrimeagen moving to Arch and Hyprland is important. Typecraft teaching beginners how to build an Arch and Hyprland setup from scratch is important (and who I just spoke to about Omarchy). Gabe Newell's Steam Deck being built on Arch and pushing Proton to over 20,000 compatible Linux games is important. You'll notice a trend here, which is that Arch Linux, a notoriously "difficult" distribution, is at the center of much of this new engagement. Despite the fact that it's been around since 2003! There's nothing new about Arch, but there's something new about the circles of people it's engaging. I've put Arch at the center of Omarchy too. Originally just because that was what Hyprland recommended. Then, after living with the wonders of 90,000+ packages on the community-driven AUR package repository, for its own sake. It's really good! But while Arch (and Hyprland) are having a moment amongst a new crowd, it's also "just" Linux at its core. And Linux really is the star of the show. The perfect, free, and open alternative that was just sitting around waiting for developers to finally have had enough of the commercial offerings from Apple and Microsoft. Now obviously there's a taste of "new vegan sees vegans everywhere" here. You start talking about Linux, and you'll hear from folks already in the community or those considering the move too. It's easy to confuse what you'd like to be true with what is actually true. And it's definitely true that Linux is still a niche operating system on the desktop. Even among developers. Apple and Microsoft sit on the lion's share of the market share. But the mind share? They've been losing that fast. The window is open for a major shift to happen. First gradually, then suddenly. It feels like morning in Linux land!

10 hours ago 2 votes
All about Svelte 5 snippets

Snippets are a useful addition to Svelte 5. I use them in my Svelte 5 projects like Edna. Snippet basics A snippet is a function that renders html based on its arguments. Here’s how to define and use a snippet: {#snippet hello(name)} <div>Hello {name}!</div> {/snippet} {@render hello("Andrew")} {@render hello("Amy")} You can re-use snippets by exporting them: <script module> export { hello }; </script> {@snippet hello(name)}<div>Hello {name}!</div>{/snippet} Snippets use cases Snippets for less nesting Deeply nested html is hard to read. You can use snippets to extract some parts to make the structure clearer. For example, you can transform: <div> <div class="flex justify-end mt-2"> <button onclick={onclose} class="mr-4 px-4 py-1 border border-black hover:bg-gray-100" >Cancel</button > <button onclick={() => emitRename()} disabled={!canRename} class="px-4 py-1 border border-black hover:bg-gray-50 disabled:text-gray-400 disabled:border-gray-400 disabled:bg-white default:bg-slate-700" >Rename</button > </div> into: {#snippet buttonCancel()} <button onclick={onclose} class="mr-4 px-4 py-1 border border-black hover:bg-gray-100" >Cancel</button > {/snippet} {#snippet buttonRename()}...{/snippet} To make this easier to read: <div> <div class="flex justify-end mt-2"> {@render buttonCancel()} {@render buttonRename()} </div> </div> snippets replace default <slot/> In Svelte 4, if you wanted place some HTML inside the component, you used <slot />. Let’s say you have Overlay.svelte component used like this: <Overlay> <MyDialog></MyDialog> </Overlay> In Svelte 4, you would use <slot /> to render children: <div class="overlay-wrapper"> <slot /> </div> <slot /> would be replaced with <MyDialog></MyDialog>. In Svelte 5 <MyDialog></MyDialog> is passed to Overlay.svelte as children property so you would change Overlay.svelte to: <script> let { children } = $props(); </script> <div class="overlay-wrapper"> {@render children()} </div> children property is created by Svelte compiler so you should avoid naming your own props children. snippets replace named slots A component can have a default slot for rendering children and additional named slots. In Svelte 5 instead of named slots you pass snippets as props. An example of Dialog.svelte: <script> let { title, children } = $props(); </script> <div class="dialog"> <div class="title"> {@render title()} </div> {@render children()} </div> And use: {#snippet title()} <div class="fancy-title">My fancy title</div> {/snippet} <Dialog title={title}> <div>Body of the dialog</div> </Dialog> passing snippets as implicit props You can pass title snippet prop implicitly: <Dialog> {#snippet title()} <div class="fancy-title">My fancy title</div> {/snippet} <div>Body of the dialog</div> </Dialog> Because {snippet title()} is a child or <Dialog>, we don’t have to pass it as explicit title={title} prop. The compiler does it for us. snippets to reduce repetition Here’s part of how I render https://tools.arslexis.io/ {#snippet row(name, url, desc)} <tr> <td class="text-left align-top" ><a class="font-semibold whitespace-nowrap" href={url}>{name}</a> </td> <td class="pl-4 align-top">{@html desc}</td> </tr> {/snippet} {@render row("unzip", "/unzip/", "unzip a file in the browser")} {@render row("wc", "/wc/", "like <tt>wc</tt>, but in the browser")} It saves me copy & paste of the same HTML and makes the structure more readable. snippets for recursive rendering Sometimes you need to render a recursive structure, like nested menus or file tree. In Svelte 4 you could use <svelte:self> but the downside of that is that you create multiple instances of the component. That means that the state is also split among multiple instances. That makes it harder to implement functionality that requires a global view of the structure, like keyboard navigation. With snippets you can render things recursively in a single instance of the component. I used it to implement nested context menus. snippets to customize rendering Let’s say you’re building a Menu component. Each menu item is a <div> with some non-trivial children. To allow the client of Menu customize how items are rendered, you could provide props for things like colors, padding etc. or you could allow ultimate flexibility by accepting an optional menuitem prop that is a snippet that renders the item. You can think of it as a headless UI i.e. you provide the necessary structure and difficult logic like keyboard navigation etc. and allow the client lots of control over how things are rendered. snippets for library of icons Before snippets every SVG Icon I used was a Svelte component. Many icons means many files. Now I have a single Icons.svelte file, like: <script module> export { IconMenu, IconSettings }; </script> {#snippet IconMenu(arg1, arg2, ...)} <svg>... icon svg</svg> {/snippet}} {#snippet IconSettings()} <svg>... icon svg</svg> {/snippet}}

yesterday 2 votes
Logical Quantifiers in Software

I realize that for all I've talked about Logic for Programmers in this newsletter, I never once explained basic logical quantifiers. They're both simple and incredibly useful, so let's do that this week! Sets and quantifiers A set is a collection of unordered, unique elements. {1, 2, 3, …} is a set, as are "every programming language", "every programming language's Wikipedia page", and "every function ever defined in any programming language's standard library". You can put whatever you want in a set, with some very specific limitations to avoid certain paradoxes.2 Once we have a set, we can ask "is something true for all elements of the set" and "is something true for at least one element of the set?" IE, is it true that every programming language has a set collection type in the core language? We would write it like this: # all of them all l in ProgrammingLanguages: HasSetType(l) # at least one some l in ProgrammingLanguages: HasSetType(l) This is the notation I use in the book because it's easy to read, type, and search for. Mathematicians historically had a few different formats; the one I grew up with was ∀x ∈ set: P(x) to mean all x in set, and ∃ to mean some. I use these when writing for just myself, but find them confusing to programmers when communicating. "All" and "some" are respectively referred to as "universal" and "existential" quantifiers. Some cool properties We can simplify expressions with quantifiers, in the same way that we can simplify !(x && y) to !x || !y. First of all, quantifiers are commutative with themselves. some x: some y: P(x,y) is the same as some y: some x: P(x, y). For this reason we can write some x, y: P(x,y) as shorthand. We can even do this when quantifying over different sets, writing some x, x' in X, y in Y instead of some x, x' in X: some y in Y. We can not do this with "alternating quantifiers": all p in Person: some m in Person: Mother(m, p) says that every person has a mother. some m in Person: all p in Person: Mother(m, p) says that someone is every person's mother. Second, existentials distribute over || while universals distribute over &&. "There is some url which returns a 403 or 404" is the same as "there is some url which returns a 403 or some url that returns a 404", and "all PRs pass the linter and the test suites" is the same as "all PRs pass the linter and all PRs pass the test suites". Finally, some and all are duals: some x: P(x) == !(all x: !P(x)), and vice-versa. Intuitively: if some file is malicious, it's not true that all files are benign. All these rules together mean we can manipulate quantifiers almost as easily as we can manipulate regular booleans, putting them in whatever form is easiest to use in programming. Speaking of which, how do we use this in in programming? How we use this in programming First of all, people clearly have a need for directly using quantifiers in code. If we have something of the form: for x in list: if P(x): return true return false That's just some x in list: P(x). And this is a prevalent pattern, as you can see by using GitHub code search. It finds over 500k examples of this pattern in Python alone! That can be simplified via using the language's built-in quantifiers: the Python would be any(P(x) for x in list). (Note this is not quantifying over sets but iterables. But the idea translates cleanly enough.) More generally, quantifiers are a key way we express higher-level properties of software. What does it mean for a list to be sorted in ascending order? That all i, j in 0..<len(l): if i < j then l[i] <= l[j]. When should a ratchet test fail? When some f in functions - exceptions: Uses(f, bad_function). Should the image classifier work upside down? all i in images: classify(i) == classify(rotate(i, 180)). These are the properties we verify with tests and types and MISU and whatnot;1 it helps to be able to make them explicit! One cool use case that'll be in the book's next version: database invariants are universal statements over the set of all records, like all a in accounts: a.balance > 0. That's enforceable with a CHECK constraint. But what about something like all i, i' in intervals: NoOverlap(i, i')? That isn't covered by CHECK, since it spans two rows. Quantifier duality to the rescue! The invariant is equivalent to !(some i, i' in intervals: Overlap(i, i')), so is preserved if the query SELECT COUNT(*) FROM intervals CROSS JOIN intervals … returns 0 rows. This means we can test it via a database trigger.3 There are a lot more use cases for quantifiers, but this is enough to introduce the ideas! Next week's the one year anniversary of the book entering early access, so I'll be writing a bit about that experience and how the book changed. It's crazy how crude v0.1 was compared to the current version. MISU ("make illegal states unrepresentable") means using data representations that rule out invalid values. For example, if you have a location -> Optional(item) lookup and want to make sure that each item is in exactly one location, consider instead changing the map to item -> location. This is a means of implementing the property all i in item, l, l' in location: if ItemIn(i, l) && l != l' then !ItemIn(i, l'). ↩ Specifically, a set can't be an element of itself, which rules out constructing things like "the set of all sets" or "the set of sets that don't contain themselves". ↩ Though note that when you're inserting or updating an interval, you already have that row's fields in the trigger's NEW keyword. So you can just query !(some i in intervals: Overlap(new, i')), which is more efficient. ↩

2 days ago 5 votes
The missing part of Espressif’s reset circuit

In the previous article, we peeked at the reset circuit of ESP-Prog with an oscilloscope, and reproduced it with basic components. We observed that it did not behave quite as expected. In this article, we’ll look into the missing pieces. An incomplete circuit For a hint, we’ll first look a bit more closely at the … Continue reading The missing part of Espressif’s reset circuit → The post The missing part of Espressif’s reset circuit appeared first on Quentin Santos.

2 days ago 3 votes