Occasional Programmer. @Cambridge_CL @OCaml_org @TC39. Formerly: @YCombinator AI SUS (Funded by @JapanGov & @TransposeVC) @Tarides_
San Francisco, CA
Joined March 2026
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Sora Morimoto retweeted
One js_of_ocaml function carried 13,539 local variables. Two new optimisation passes, variable coalescing and constant sinking, took it to 1,263 and shrank compressed output by 16%. Both are now on by default. tarides.com/blog/2026-11-12-…
Sora Morimoto retweeted
This is a pretty central question!
One direction we're taking is to integrate specifications into OxCaml, so the spec language is easy and familiar for us. @JulesJacobs5's slides point to some of the directions we're trying.
lab.julesjacobs.com/vox/talk…
Sora Morimoto retweeted
We have dumped JAX/SGLang and rewritten the entire RL and inference stack from scratch in C/C++, which took some extra time.
Training (aka pre-training) is done. Lot of cleanup was needed on the SFT data to get that mostly right. Now, 4.8 is in RL and the evals are starting to climb. We will do a soft rollout to Bot users later this week and see how it goes.
Grok 4.8 will bear no resemblance to 4.7 (thankfully). It is not yet incredible, but, this time, the foundations are built right, so I expect it to evolve to be something special.
ドリフトするというのは本当にそうで、だからこそこれを作った
teapawt.net/smorimoto/status/21185…
Leanの定理証明で堅いシステム作るとか美しく感じるからエンジニアが飛びつくのはわかるけどさぁ
本当に価値の高いものってインターフェースの境界部分みたいな泥臭いところにあって、証明が仕様変更のたびに壊れるのでただお荷物が増えるだけになりがちだよ
定理証明が活きるような強いモジュールって、それこそ新しいプログラミング言語だったりランタイムだったり、それ自体の世界が広いものなので、やるならRubyを超える世界的な何かを作るぞ、ぐらいの気概が必要
たかがSaaS開発ぐらいで必要になることは、まぁないと思ってた方がいいと思う
ほぼ状態機械のモデル検査として普通のテストで代替できます
そしてフロンティアのコーディングモデルならほぼ勝手に不変条件を決めながらテストを書いてくれるので意識する必要もないという
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Sora Morimoto retweeted
I had Opus 5.5 formalize CPython in Lean: 613,318 lines of Lean that copy Python's internals line by line, tested against the real interpreter and checked by Lean.
On the way it found real bugs in Python, including crashes from plain Python code. 🧵
Introducing rocq-typescript-extraction, a Rocq plugin that extracts Rocq definitions to TypeScript.
- Inductive Types, Records, Recursive Functions, Modules, and Functors
- Generates erasable TypeScript ES modules, checked under strict settings
- Number and BigInt presets map integers to number or bigint
Experimental. Read the limitations before use.
Sora Morimoto retweeted
introducing TScert, a sound core for TypeScript.
- TypeScript functions accepted only with a proof
- a checker whose soundness is proved in Lean
- first target: its own front end, 628 of 684 functions verified
a research project, unfinished by design. read it, inspect it 👇
Sora Morimoto retweeted
Building TScert: TypeScript based on a formally verified core, one feature at a time.
@typescript made smart, pragmatic tradeoffs on a very hard problem. With unlimited agents, those tradeoffs can be revisited.
First milestone: TScert verifying its own front end, which uses the TypeScript compiler's libraries.
189 functions out of 499 verified so far.
Sora Morimoto retweeted
Today we announce 1Password for Agents platform, building with companies @Muse, SpaceX Super Intelligence Grok @Bot, @AnthropicAI’s @Claudeai, @OpenAI, @TownAI, @Browserbase, @Browser_use, @heydana_ai, Instinct, @usekernel, @Perplexity_ai, @tryramp, @Tomo, and @wajo_ai, with more integrations on the way. 🎉
We've heard from so many of our customers who want to use these new personal AI agents to help them get more done, but want more control over what the agent can access with the same trust and ease of use they get when using 1Password directly.
1Password for Agents gives your agents access without giving up your passwords. When an agent reaches a sign-in form, it requests a credential from your vault. If you approve the request, 1Password directly auto-fills the credential in the destination site so the agent can’t see or take possession of the credentials.
The agent gets the task done, but it doesn’t get your passwords..
You stay in control. 1Password for Agents free and optional for personal and family accounts. Unless you opt-in to an agent connector, agents cannot touch your vault.
➡️Learn more: bit.ly/487da6J
Sora Morimoto retweeted
DeepSeek V4.1 Flash 1017 is now available for your agents. It features a massive 1M token context window and smart reasoning out of the box.
developers.cloudflare.com/ch…
Sora Morimoto retweeted
TanStack Start 1.0 is officially stable! 🎉
A full-stack web framework for React and Solid, already used to build millions of apps, from Fortune 500 companies to your favorite tools and weekend projects.
tanstack.com/start
Sora Morimoto retweeted
Le Chonk cooked on visual grounding.
Pinpoints exactly where things are in an image.
42% on Dense 200, ahead of even frontier closed models..
