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I’ve found myself more often using web apps instead of dedicated desktop applications at work. It seems that in general, desktop apps have been getting slower and more resource intensive lately. The trend of teams using Electron or the Chromium Embedded Framework in order to ship dedicated desktop apps has also contributed to this. If you are using the desktop versions of Slack, Skype, Atom, Spotify, VS Code, Github Desktop, or Discord (plus many more) you are likely running an entirely separate instance of Google Chrome as part of those apps. That’s a lot of overhead. This is why I prefer web apps. They don’t usually consume so much RAM, they generally start up really quickly and best of all they don’t require constant updating. Below is my list of useful web apps and tools that make me more productive at work. Productivity Slack Web - I also like the Refined extension that adds some good features Google Docs, Sheets, Slides - Duh Grammarly - Nice writing utility Simplenote -...
over a year ago

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More from Alex Meub

The Magic of Solving Problems with 3D Printing

3D Printing has allowed me to be creative in ways I never thought possible. It has allowed me to create products that provide real value, products that didn’t exist before I designed them. On top of that, it’s satisfied my desire to ship products, even if the end-user is just me. Another great thing is how quickly 3D printing provides value. If I see a problem, I can design and print a solution that works in just a few hours. Even if I’m the only one who benefits, that’s enough. But sharing these creations takes the experience even further. When I see others use or improve on something I’ve made, it makes the process feel so much more worthwhile. It gives me the same feeling of fulfillment when I ship software products at work. Before mass-market 3D printing, creators would need to navigate the complexity and high costs of mass-production methods (like injection molding) even to get a limited run of a niche product produced. With 3D printing, they can transfer the cost of production to others. Millions of people have access to good 3D printers now (at home, work, school, libraries, maker spaces), which means almost anyone can replicate a design. Having a universal format for sharing 3D designs dramatically lowers the effort that goes into sharing them. Creators can share their design as an STL file, which describes the surface geometry of their 3D object as thousands of little triangles. This “standard currency” of the 3D printing world is often all that is required to precisely replicate a design. This dramatically lowers the effort that goes into sharing printable designs. The widespread availability of 3D printers and the universal format for sharing 3D designs has allowed 3D-printed products to not only exist but thrive in maker communities. This is the magic of 3D printing: it empowers individuals to solve their own problems by designing solutions while enabling others to reproduce those designs at minimal cost and effort.

6 months ago 88 votes
Building the DataToaster 3000

Last summer, I was inspired by a computer that was built inside of a toaster that I saw at a local computer recycling store. The idea of a computer with the design of a home appliance was really appealing and so was the absurdity of it. It occurred to me that this would be a fun and creative way to integrate technology into my life. After thinking about it, I realized there’s also something visually appealing about how simple and utilitarian toasters are. I have major nostalgia for the famous After Dark screensaver and I think this is why. I knew now that I wanted to make my own attempt at a toaster/computer hybrid. I decided to do just that when I created the DataToaster 3000: a toaster NAS with two 3.5 inch hard disk docking stations built inside it. The hard disks can be easily swapped out (while powered off) without taking anything apart. It uses a Zimaboard x86-64 single board computer and even has a functional knob that controls the color of the power LED. I designed a fairly complex set of 3D-printed parts that attach to the base of the toaster and hold everything neatly in place. This allows it to be easily disassembled if I ever want to make any modifications and also hopefully makes the project easier to build for others. It’s a ridiculous thing but I really do love it. You can find the build guide on Instructables and the 3D models on Printables.

9 months ago 77 votes
Building a Removable Bike Basket for the Yepp Rack

I wanted to add more hauling capacity to my bike and was looking for something compatible with my Yepp rear rack. I also use my rack with a child seat (the Yepp Maxi) which has a mechanism that allows it to attach and detach easily without sacrificing safety. I was thinking it would be great to build a Yepp compatible rear basket that could I just as quickly attach/detach from my rack. I designed a removable Yepp-rack-compatible rear basket that consists of a milk crate, some plywood for stability and a 3D printed bracket threaded for M6 bolts which hold it all together. It can be attached and removed in seconds and is very secure. 3D Printed Mounting Bracket I modeled my mounting bracket after the one on the Yepp Maxi childseat. After a few iterations I was able to make it perfectly fit. I printed it in PETG filament so it was UV resistant and then installed threaded inserts for M6 bolts to attach it to the milk crate and my rear rack. 3D Print and Build Instructions You can find the 3D print on Printables and a full build guide on Instructables.

10 months ago 73 votes
The Yoto Mini is Perfect

The Yoto Mini is one of my favorite products. The team behind it deeply understands its users and put just the right set of features into a brilliantly designed package. I have no affiliation with Yoto, I’m just a happy customer with kids who love it. If you aren’t aware, Yoto is an audio platform for kids with what they call “screen-free” audio players (even though they have little pixel LED screens on them). The players are Wi-Fi enabled and support playing audio from credit card-sized NFC tags called Yoto cards. Yoto sells audio players and also licenses audio content and offers it on its platform as well. The cards themselves do not contain any audio data, just a unique ID of the audio content that is pulled from the cloud. After content is pulled on the first play, it is saved and played locally from the player after that. Yoto also supports playing podcasts and music stations without using cards. Their marketing puts a lot of emphasis on the platform being “ad-free” which is mostly true as there are never ads on Yoto cards or official Yoto podcasts. However, some of the other podcasts do advertise their content. So, what’s so great about the Yoto Mini? This concept isn’t new as there have been many examples of audio players for kids over the years. What sets it apart is how every detail of the hardware, mobile app, and exclusive content is meticulously designed and well executed. Yoto Mini Hardware The main input methods of the Yoto Mini are two orange knobs, turning the left knob controls volume and the right knob navigates chapters or tracks. Pressing the right knob instantly plays the Yoto Daily podcast and pressing it twice plays Yoto Radio (a kid-friendly music station). These actions are both configurable in the mobile app. The NFC reader slot accepts Yoto cards and instantly starts playing where you left off after you insert one. It has a high-quality speaker that can be surprisingly loud, an on/off button, a USB-C charging port, an audio output jack, and a small pixel display that shows images related to the audio content. The Yoto Mini is also surprisingly durable. My kids have dropped it many times on hard surfaces and it still basically looks as good as new. Yoto understands that the physical audio player itself is primarily used by younger kids and the design reflects this. My 3-year-old daughter was able to figure out how to turn it on/off, start listening to books using cards, and play the Yoto Daily podcast each morning which was empowering for her. This was her first technology product that she was fully capable of using without help from an adult. I can’t think of many other products that do this better. Yoto Mobile App The Yoto team understands that parents are users of this product too, mostly for managing the device and its content. Yoto has built a very good mobile experience that is tightly integrated with the hardware and provides all the features you’d want as a parent. From the app, you can start playing any of the content from cards you own on the player or your phone (nice if your kids lose a card), you can set volume limits for both night and day time, you can set alarms, and configure the shortcut buttons. You can record audio onto a blank Yoto card (which comes with the player) if your kid wants to create their own story, link it to their favorite podcast or favorite music. The app even lets you give each track custom pixel art that is displayed on the screen. Audio Content By far the most underrated feature is a daily podcast called Yoto Daily. This ad-free podcast is run by a charming British host and it is funny, entertaining, and educational. My kids (now 4 and 7) look forward to it every morning and the fact that it’s daily free content that is integrated directly into the Yoto hardware is amazing. To me, this is the killer feature, as my kids get to enjoy it every day and it’s always fresh and interesting. Yoto licenses content from child book authors, popular kid’s shows, movies, and music (recently the Beatles) which are made available in their store. I also discovered that Yoto does not seem to lock down its content with DRM. My son traded some Yoto cards with a friend and I assumed there would be some kind of transfer or de-registration process but to my surprise, they just worked without issue. Conclusion The Yoto Mini is a delightful product. The team behind it thought through every detail and made it an absolute joy to use both as a child and parent. I’m impressed at how well the Yoto team understands their users and prioritizes simplicity and ease of use above all else.

a year ago 65 votes
How To Quiet Down Your 3D Printer

When I first got my 3D printer, I built an enclosure to protect it from dust, maintain a consistent temperature, and minimize noise. I was surprised to find that the enclosure didn’t reduce noise that significantly. I then placed a patio paver under my printer, which made it noticeably quieter, but it was still audible from other rooms in my house. Recently, I found the most effective noise reduction solution: squash balls. These balls are designed with varying bounce levels, indicated by colored dots. The “double-yellow dot” balls have a very low bounce, making them ideal for dampening vibration, which is the primary cause of printer noise. I found an existing design for squash ball feet, printed it, and hot glued them evenly under my patio paver. My current setup includes the enclosure, patio paver, and squash balls under the paver. Now, the printer is so quiet that I actually can’t tell if it’s running, even when I’m in the same room. Occasionally, I will hear the stepper motors, but that’s rare. Most of the time I need to open the enclosure to make sure it’s still printing.

a year ago 34 votes

More in programming

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. ↩

17 hours ago 3 votes
Setting Element Ordering With HTML Rewriter Using CSS

After shipping my work transforming HTML with Netlify’s edge functions I realized I have a little bug: the order of the icons specified in the URL doesn’t match the order in which they are displayed on screen. Why’s this happening? I have a bunch of links in my HTML document, like this: <icon-list> <a href="/1/">…</a> <a href="/2/">…</a> <a href="/3/">…</a> <!-- 2000+ more --> </icon-list> I use html-rewriter in my edge function to strip out the HTML for icons not specified in the URL. So for a request to: /lookup?id=1&id=2 My HTML will be transformed like so: <icon-list> <!-- Parser keeps these two --> <a href="/1/">…</a> <a href="/2/">…</a> <!-- But removes this one --> <a href="/3/">…</a> </icon-list> Resulting in less HTML over the wire to the client. But what about the order of the IDs in the URL? What if the request is to: /lookup?id=2&id=1 Instead of: /lookup?id=1&id=2 In the source HTML document containing all the icons, they’re marked up in reverse chronological order. But the request for this page may specify a different order for icons in the URL. So how do I rewrite the HTML to match the URL’s ordering? The problem is that html-rewriter doesn’t give me a fully-parsed DOM to work with. I can’t do things like “move this node to the top” or “move this node to position x”. With html-rewriter, you only “see” each element as it streams past. Once it passes by, your chance at modifying it is gone. (It seems that’s just the way these edge function tools are designed to work, keeps them lean and performant and I can’t shoot myself in the foot). So how do I change the icon’s display order to match what’s in the URL if I can’t modify the order of the elements in the HTML? CSS to the rescue! Because my markup is just a bunch of <a> tags inside a custom element and I’m using CSS grid for layout, I can use the order property in CSS! All the IDs are in the URL, and their position as parameters has meaning, so I assign their ordering to each element as it passes by html-rewriter. Here’s some pseudo code: // Get all the IDs in the URL const ids = url.searchParams.getAll("id"); // Select all the icons in the HTML rewriter.on("icon-list a", { element: (element) => { // Get the ID const id = element.getAttribute('id'); // If it's in our list, set it's order // position from the URL if (ids.includes(id)) { const order = ids.indexOf(id); element.setAttribute( "style", `order: ${order}` ); // Otherwise, remove it } else { element.remove(); } }, }); Boom! I didn’t have to change the order in the source HTML document, but I can still get the displaying ordering to match what’s in the URL. I love shifty little workarounds like this! Email · Mastodon · Bluesky

17 hours ago 2 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.

17 hours ago 2 votes
clamp / median / range

Here are a few tangentially-related ideas vaguely near the theme of comparison operators. comparison style clamp style clamp is median clamp in range range style style clash? comparison style Some languages such as BCPL, Icon, Python have chained comparison operators, like if min <= x <= max: ... In languages without chained comparison, I like to write comparisons as if they were chained, like, if min <= x && x <= max { // ... } A rule of thumb is to prefer less than (or equal) operators and avoid greater than. In a sequence of comparisons, order values from (expected) least to greatest. clamp style The clamp() function ensures a value is between some min and max, def clamp(min, x, max): if x < min: return min if max < x: return max return x I like to order its arguments matching the expected order of the values, following my rule of thumb for comparisons. (I used that flavour of clamp() in my article about GCRA.) But I seem to be unusual in this preference, based on a few examples I have seen recently. clamp is median Last month, Fabian Giesen pointed out a way to resolve this difference of opinion: A function that returns the median of three values is equivalent to a clamp() function that doesn’t care about the order of its arguments. This version is written so that it returns NaN if any of its arguments is NaN. (When an argument is NaN, both of its comparisons will be false.) fn med3(a: f64, b: f64, c: f64) -> f64 { match (a <= b, b <= c, c <= a) { (false, false, false) => f64::NAN, (false, false, true) => b, // a > b > c (false, true, false) => a, // c > a > b (false, true, true) => c, // b <= c <= a (true, false, false) => c, // b > c > a (true, false, true) => a, // c <= a <= b (true, true, false) => b, // a <= b <= c (true, true, true) => b, // a == b == c } } When two of its arguments are constant, med3() should compile to the same code as a simple clamp(); but med3()’s misuse-resistance comes at a small cost when the arguments are not known at compile time. clamp in range If your language has proper range types, there is a nicer way to make clamp() resistant to misuse: fn clamp(x: f64, r: RangeInclusive<f64>) -> f64 { let (&min,&max) = (r.start(), r.end()); if x < min { return min } if max < x { return max } return x; } let x = clamp(x, MIN..=MAX); range style For a long time I have been fond of the idea of a simple counting for loop that matches the syntax of chained comparisons, like for min <= x <= max: ... By itself this is silly: too cute and too ad-hoc. I’m also dissatisfied with the range or slice syntax in basically every programming language I’ve seen. I thought it might be nice if the cute comparison and iteration syntaxes were aspects of a more generally useful range syntax, but I couldn’t make it work. Until recently when I realised I could make use of prefix or mixfix syntax, instead of confining myself to infix. So now my fantasy pet range syntax looks like >= min < max // half-open >= min <= max // inclusive And you might use it in a pattern match if x is >= min < max { // ... } Or as an iterator for x in >= min < max { // ... } Or to take a slice xs[>= min < max] style clash? It’s kind of ironic that these range examples don’t follow the left-to-right, lesser-to-greater rule of thumb that this post started off with. (x is not lexically between min and max!) But that rule of thumb is really intended for languages such as C that don’t have ranges. Careful stylistic conventions can help to avoid mistakes in nontrivial conditional expressions. It’s much better if language and library features reduce the need for nontrivial conditions and catch mistakes automatically.

yesterday 3 votes
C++ engineering decision in SumatraPDF code

SumatraPDF is a medium size (120k+ loc, not counting dependencies) Windows GUI (win32) C++ code base started by me and written by mostly 2 people. The goals of SumatraPDF are to be: fast small packed with features and yet with thoughtfully minimal UI It’s not just a matter of pride in craftsmanship of writing code. I believe being fast and small are a big reason for SumatraPDF’s success. People notice when an app starts in an instant because that’s sadly not the norm in modern software. The engineering goals of SumatraPDF are: reliable (no crashes) fast compilation to enable fast iteration SumatraPDF has been successful achieving those objectives so I’m writing up my C++ implementation decisions. I know those decisions are controversial. Maybe not Terry Davis level of controversial but still. You probably won’t adopt them. Even if you wanted to, you probably couldn’t. There’s no way code like this would pass Google review. Not because it’s bad but becaues it’s different. Diverging from mainstream this much is only feasible if you have total control: it’s your company or your own open-source project. If my ideas were just like everyone else’s ideas, there would be little point in writing about them, would it? Use UTF8 strings internally My app only runs on Windows and a string native to Windows is WCHAR* where each character consumes 2 bytes. Despite that I mostly use char* assumed to be utf8-encoded. I only decided on that after lots of code was written so it was a refactoring oddysey that is still ongoing. My initial impetus was to be able to compile non-GUI parts under Linux and Mac. I abandoned that goal but I think that’s a good idea anyway. WCHAR* strings are 2x larger than char*. That’s more memory used which also makes the app slower. Binaries are bigger if string constants are WCHAR*. The implementation rule is simple: I only convert to WCHAR* when calling Windows API. When Windows API returns WCHA* I convert it to utf-8. No exceptions Do you want to hear a joke? “Zero-cost exceptions”. Throwing and catching exceptions generate bloated code. Exceptions are a non-local control flow that makes it hard to reason about program. Every memory allocation becomes a potential leak. But RAII, you protest. RAII is a “solution” to a problem created by exceptions. How about I don’t create the problem in the first place. Hard core #include discipline I wrote about it in depth. My objects are not shy I don’t bother with private and protected. struct is just class with guts exposed by default, so I use that. While intellectually I understand the reasoning behind hiding implementation details in practices it becomes busy work of typing noise and then even more typing when you change your mind about visibility. I’m the only person working on the code so I don’t need to force those of lesser intellect to write the code properly. My objects are shy At the same time I minimize what goes into a class, especially methods. The smaller the class, the faster the build. A common problem is adding too many methods to a class. You have a StrVec class for array of strings. A lesser programmer is tempted to add Join(const char* sep) method to StrVec. A wise programmer makes it a stand-alone function: Join(const StrVec& v, const char* sep). This is enabled by making everything in a class public. If you limit visibility you then have to use friendto allow Join() function access what it needs. Another example of “solution” to self-inflicted problems. Minimize #ifdef #ifdef is problematic because it creates code paths that I don’t always build. I provide arm64, intel 32-bit and 64-bit builds but typically only develop with 64-bit intel build. Every #ifdef that branches on architecture introduces potential for compilation error which I’ll only know about when my daily ci build fails. Consider 2 possible implementations of IsProcess64Bit(): Bad: bool IsProcess64Bit() { #ifdef _WIN64 return true; #else return false; #endif } Good: bool IsProcess64Bit() { return sizeof(uintptr_t) == 8; } The bad version has a bug: it was correct when I was only doing intel builds but became buggy when I added arm64 builds. This conflicts with the goal of smallest possible size but it’s worth it. Stress testing SumatraPDF supports a lot of very complex document and image formats. Complex format require complex code that is likely to have bugs. I also have lots of files in those formats. I’ve added stress testing functionality where I point SumatraPDF to a folder with files and tell it to render all of them. For greater coverage, I also simulate some of the possible UI actions users can take like searching, switching view modes etc. Crash reporting I wrote about it in depth. Heavy use of CrashIf() C/C++ programmers are familiar with assert() macro. CrashIf() is my version of that, tailored to my needs. The purpose of assert / CrashIf is to add checks to detect incorrect use of APIs or invalid states in the program. For example, if the code tries to access an element of an array at an invalid index (negative or larger than size of the array), it indicates a bug in the program. I want to be notified about such bugs both when I test SumatraPDF and when it runs on user’s computers. As the name implies, it’ll crash (by de-referencing null pointer) and therefore generate a crash report. It’s enabled in debug and pre-release builds but not in release builds. Release builds have many, many users so I worry about too many crash reports. premake to generate Visual Studio solution Visual Studio uses XML files as a list of files in the project and build format. The format is impossible to work with in a text editor so you have no choice but to use Visual Studio to edit the project / solution. To add a new file: find the right UI element, click here, click there, pick a file using file picker, click again. To change a compilation setting of a project or a file? Find the right UI element, click here, click there, type this, confirm that. You accidentally changed compilation settings of 1 file out of a hundred? Good luck figuring out which one. Go over all files in UI one by one. In other words: managing project files using Visual Studio UI is a nightmare. Premake is a solution. It’s a meta-build system. You define your build using lua scripts, which look like test configuration files. Premake then can generate Visual Studio projects, XCode project, makefiles etc. That’s the meta part. It was truly a life server on project with lots of files (SumatraPDF’s own are over 300, many times more for third party libraries). Using /analyze and cppcheck cppcheck and /analyze flag in cl.exe are tools to find bugs in C++ code via static analysis. They are like a C++ compiler but instead of generating code, they analyze control flow in a program to find potential programs. It’s a cheap way to find some bugs, so there’s no excuse to not run them from time to time on your code. Using asan builds Address Sanitizer (asan) is a compiler flag /fsanitize=address that instruments the code with checks for common memory-related bugs like using an object after freeing it, over-writing values on the stack, freeing an object twice, writing past allocated memory. The downside of this instrumentation is that the code is much slower due to overhead of instrumentation. I’ve created a project for release build with asan and run it occasionally, especially in stress test. Write for the debugger Programmers love to code golf i.e. put us much code on one line as possible. As if lines of code were expensive. Many would write: Bad: // ... return (char*)(start + offset); I write: Good: // ... char* s = (char*)(start + offset); return s; Why? Imagine you’re in a debugger stepping through a debug build of your code. The second version makes it trivial to set a breakpoint at return s line and look at the value of s. The first doesn’t. I don’t optimize for smallest number of lines of code but for how easy it is to inspect the state of the program in the debugger. In practice it means that I intentionally create intermediary variables like s in the example above. Do it yourself standard library I’m not using STL. Yes, I wrote my own string and vector class. There are several reasons for that. Historical reason When I started SumatraPDF over 15 years ago STL was crappy. Bad APIs Today STL is still crappy. STL implementations improved greatly but the APIs still suck. There’s no API to insert something in the middle of a string or a vector. I understand the intent of separation of data structures and algorithms but I’m a pragmatist and to my pragmatist eyes v.insert (v.begin(), myarray, myarray+3); is just stupid compared to v.inert(3, el). Code bloat STL is bloated. Heavy use of templates leads to lots of generated code i.e. surprisingly large binaries for supposedly low-level language. That bloat is invisible i.e. you won’t know unless you inspect generated binaries, which no one does. The bloat is out of my control. Even if I notice, I can’t fix STL classes. All I can do is to write my non-bloaty alternative, which is what I did. Slow compilation times Compilation of C code is not fast but it feels zippy compared to compilation of C++ code. Heavy use of templates is big part of it. STL implementations are over-templetized and need to provide all the C++ support code (operators, iterators etc.). As a pragmatist, I only implement the absolute minimum functionality I use in my code. I minimize use of templates. For example Str and WStr could be a single template but are 2 implementations. I don’t understand C++ I understand the subset of C++ I use but the whole of C++ is impossibly complicated. For example I’ve read a bunch about std::move() and I’m not confident I know how to use it correctly and that’s just one of many complicated things in C++. C++ is too subtle and I don’t want my code to be a puzzle. Possibility of optimized implementations I wrote a StrVec class that is optimized for storing vector of strings. It’s more efficient than std::vector<std::string> by a large margin and I use it extensively. Temporary allocator and pool allocators I use temporary allocators heavily. They make the code faster and smaller. Technically STL has support for non-standard allocators but the API is so bad that I would rather not. My temporary allocator and pool allocators are very small and simple and I can add support for them only when beneficial. Minimize unsigned int STL and standard C library like to use size_t and other unsigned integers. I think it was a mistake. Go shows that you can just use int. Having two types leads to cast-apalooza. I don’t like visual noise in my code. Unsigned are also more dangerous. When you substract you can end up with a bigger value. Indexing from end is subtle, for (int i = n; i >= 0; i--) is buggy because i >= 0 is always true for unsigned. Sadly I only realized this recently so there’s a lot of code still to refactor to change use of size_t to int. Mostly raw pointers No std::unique_ptr for me. Warnings are errors C++ makes a distinction between compilation errors and compilation warnings. I don’t like sloppy code and polluting build output with warning messages so for my own code I use a compiler flag that turns warnings into errors, which forces me to fix the warnings.

yesterday 2 votes