I Didn't Mean to Build a Programming Language
I'm building a programming language. Written like that, it sounds as if I had always dreamed about compilers, read the Dragon Book cover to cover, and spent years waiting for the day I could finally design my own language. Not even close. I was just writing ordinary web applications and constantly thinking things like: "Why do I have to write it this way here?" or: "Wouldn't this feel better if I could write it a little more directly?" I kept digging into those small annoyances instead of ignoring them, one by one, and somehow they turned into a programming language. It's called Seseragi . Seseragi (せせらぎ) is a Japanese word for the gentle sound or flow of a small stream. I wanted my programming language to have a Japanese name. https://github.com/KentaroMorishita/seseragi https://seseragi.vercel.app/ https://seseragi.vercel.app/tour/ It's still experimental and pre-release, but a Rust compiler, CLI, LSP, formatter, WASM Playground, Signal, and Web UI are already working to a surprising degree. Even I sometimes look at it and think, "How far is this thing going?" It started with being tired of if In 2024, I wrote this article on Qiita. https://qiita.com/KentaroMorishita/items/6329d20fbc6f98f72864 The title alone probably tells you I was already heading somewhere weird. I don't think I hated if itself. What bothered me was the feeling of tracing conditional branches as statements . That was also why I liked ternary expressions. Not just because they were short. They were expressions, so I could take the result directly as a value. const label = isLoading ? " Loading... " : hasError ? " Error " : " Ready " Of course, once these grow, they become painful too. So I started building my own match and when abstractions on top of TypeScript. Looking back, I was trying pretty hard to fight the language. But the underlying desire was already clear: I'd rather construct values than chase control flow. When I look at Seseragi now, the symptoms had started long before the languag