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Earlier today on Hacker News Scrappy made the rounds, with the explicit tagline “make little apps for you and your friends”. I always like to see new projects in this vein. That’s why I’d like to outline my alternative approach, which Works cross-platform and on mobile devices by default, Doesn’t require any app store tomfoolery, Has great uptime built in, Gives you just enough data persistence to not get in your way, and Is owned by you, forever....

This works as of, at least, Anki 24.06.3. According to the Mozilla Developer Network, The <details> HTML element creates a disclosure widget in which information is visible only when the widget is toggled into an open state. In standard web browsers, absent any CSS to the contrary, a <details> tag starts closed until further notice. Since Anki is basically a local web browser on top of a timer, this also works there....

Language learning for the contemporary adult learner can be broken down roughly into four highly correlated, but distinct, skillsets. Passive understanding Active production The written word Reading Writing The spoken word Listening Speaking You may know from my FOSS software that I have been learning Finnish for the past 4 years or so. For the first few years I pretty much focused exclusively on reading comprehension, as I consider that to be the easiest quadrant to skill up in first....

As a nerdy, working-class kid who grew up in the 1990s, knowing what time it actually was was a luxury I rarely had access to before I was 12 or so and my parents finally got an Internet connection with its attendant link to the Network Time Protocol. If you had told me I could have not just a watch but an entire machine that Never lost the time, Did what I wanted, how I wanted it, and Could be programmed to do what I want, how I want it on a schedule, I would have had to substantially revise my Christmas wishlist....

Perl 5 went through a long nadir of unpopularity due in large part to its deserved “Write Once, Read Never” reputation. So I was surprised to find out not only is it installed by default on Debian, it’s installed nearly everywhere by default. It’s even the non-shell scripting language of choice on OpenBSD! Perhaps the only thing more impressive than Perl’s utter ubiquity is its longevity. The latest major version of Perl was first released in 1994....

Below is a GIF of tsk, my pocket Finnish-to-English dictionary, running in my terminal emulator of choice under Linux. It’s what the kids call a TUI, a graphical program that just happens to drive its graphics using terminal graphics instead of graphics-graphics. Insert GIF here. You can probably tell that this program fits neatly into the “home-cooked meal” clade of programs. There is a very straightforward problem I want solved - fast, single-executable-portable dictionary lookup, with a few conveniences for the busy language learner layered on top....

Peanut butter and jelly are complementary goods, as are cars and gasoline, newer cars and electricity, electricity and basically everything else. We don’t normally think of, say, Docker and Kubernetes as complementary goods in software engineering, because you can get both for the low price of free. Or can you? You still have to invest time in learning both, and as the famous saying goes… Say it takes X hours to learn Docker adequately....

If you followed “Binary search isn’t about search” and “Binary search isn’t about search II” properly, the following statements should suffice as a summary: 1 2 L[0:l] < T < L[r:len(L)] # ordinary binary search loop invariant L[0:l] < T <= L[r:len(L)] # leftwise binary search loop invariant Let’s complete the triptych. Take a wild guess what invariant we use for rightmost element binary search: 1 L[0:l] <= T < L[r:len(L)] # rightwise binary search loop invariant A motivating example Consider again an array like...

In the first “Binary search isn’t about search” post, we spoke about using assert statements to enforce your loop invariants. Our plain old everyday binary search invariant can be summarized as such: For all x in L[0:l]1, x is strictly less than T, the element we are searching for. For all y in L[r:len(L)]2, y is strictly greater than T, the element we are searching for. Or, if we want to be even terser, we could note this as simply...

Suppose you’re trying to track down a bug that appeared in a series of Git commits. You’ve been idly keeping track of where this bug appears in your lucky commits by hand, while busy with other things. So far you’ve compiled this table: 1 2 3 4 5 6 7 8 9 10 0000000 🧼 clean, no bug. 0000001 🧼 0000002 🧼 0000003 🧼 0000004 🧼 0000005 🧼 0000006 🐛 bug first appears here....