GitHub tip-hub: habitual permalinks

Memory mapping a file for reading sounds nice: turn inconvenient read calls and manual buffering into just simple indexing of a memory… but it does blocking IO under the hood, turn a &[u8] byte arrays into an async hazard and making “concurrent” async code actually run sequentially! Code affected likely runs slower, underutilises machine...

Encoding data in decimal requires many more characters than the same data encoded in base64—06513249 vs YWJj—but using decimal is better when stored in a QR code. The magic of QR modes means all those extra digits are stored efficiently, almost as though there was no encoding at all. Decimal encoding makes for QR codes that store more data, or...

Governments here in Australia have been telling us to keep distance from each other. Surprisingly, the same government has simultaneously put out posters that required people to get close, unnecessarily. They contain QR codes for contact-tracing check-ins that are small and dense, meaning they’re hard to scan. How could they be better? Here’s...

Error correction sounds good. It means fewer errors, right? When it comes to QR codes, that’ll mean easier scanning for people, surely? It seems like that’s not the whole story. I wondered about this, and couldn’t find an answer, so I did some exploration, and found there’s two factors in tension: the error correction on one hand, and the...

Taking shortcuts? Leaving edge-cases unconsidered and unhandled? Is this engineering?! My approach to programming and software engineering has been shaped by years of building open source compilers and libraries, where those edge cases matter, reliability is crucial and flexibility is important. It’s been a breath of fresh air to take a step back...