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0 pointsthrowitaway11231y ago0 comments

> I mean, I can't think of a time a high profile project written in a lower level representation got ported to a higher level language.

Prisma is currently being rewritten from Rust to TypeScript: https://www.prisma.io/blog/rust-to-typescript-update-boostin...

> Yet projects inevitably get to the stage where a more native representation wins out.

I would be careful about extrapolating the performance gains achieved by the Go TypeScript port to non-compiler use cases. A compiler is perhaps the worst use case for a language like JS, because it is both (as Anders Hejlsberg refers to it) an "embarassingly parallel task" (because each source file can be parsed independently), but also requires the results of the parsing step to be aggregated and shared across multiple threads (which requires shared memory multithreading of AST objects). Over half of the performance gains can be attributed to being able to spin up a separate goroutine to parse each source file. Anders explains it perfectly here: https://www.youtube.com/watch?v=ZlGza4oIleY&t=2027s

We might eventually get shared memory multithreading (beyond Array Buffers) in JS via the Structs proposal [1], but that remains to be seen.

[1] https://github.com/tc39/proposal-structs?tab=readme-ov-file

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zoogeny1y ago

I think the Prisma case is a bit of a red herring. First, they are using WASM which itself is a a low-level representation. Second, the performance gains appear primarily in avoiding the marshalling of data from JavaScript into Rust (and back again I presume). Basically, if the majority of your application is already in JavaScript and expects primarily to interact with other code written in JavaScript, it usually doesn't make sense to serialize your data, pass it to another runtime for some processing, then pass the result back.

As for the "compilers are special" reasoning, I don't ascribe to it. I suppose because it implies the opposite: something (other than a compiler) is especially suited to run well in a scripting language. But the former doesn't imply the later in reality and so the case should be made independently. The Prisma case is one: you are already dealing with JavaScript objects so it is wise to stay in JavaScript. The old cases I would choose the scripting language (familiarity, speed of adding new features, ability to hire a team quickly) seem to be eroding in the face of LLMs.

throwitaway1123OP1y ago

> First, they are using WASM which itself is a a low-level representation.

WASM is used to generate the query plan, but query execution now happens entirely within TypeScript, whereas under the previous architecture both steps were handled by Rust. So in a very literal sense some of the Rust code is being rewritten in TypeScript.

> Basically, if the majority of your application is already in JavaScript and expects primarily to interact with other code written in JavaScript, it usually doesn't make sense to serialize your data, pass it to another runtime for some processing, then pass the result back.

My point was simply to refute the assertion that once software is written in a low level language, it will never be converted to a higher level language, as if low level languages are necessarily the terminal state for all software, which is what your original comment seemed to be suggesting. This feels like a bit of a "No true Scotsman" argument: https://en.wikipedia.org/wiki/No_true_Scotsman

> As for the "compilers are special" reasoning, I don't ascribe to it.

Compilers (and more specifically lexers and parsers) are special in the sense that they're incredibly well suited for languages with shared memory multithreading. Not every workload fits that profile.

> The old cases I would choose the scripting language (familiarity, speed of adding new features, ability to hire a team quickly) seem to be eroding in the face of LLMs.

I'm not an AI pessimist, but I'm also not an AI maximalist who is convinced that AI will completely eliminate the need for human code authoring and review, and as long as humans are required to write and review code, then those benefits still apply. In fact, one of the stated reasons for the Prisma rewrite was "skillset barriers". "Contributing to the query engine requires a combination of Rust and TypeScript proficiency, reducing the opportunity for community involvement." [1]

[1] https://www.prisma.io/blog/from-rust-to-typescript-a-new-cha...

zoogeny1y ago

I'm not denying the facts of the matter, I am denying the conclusion. The circumstances of the situation are relevant. Marshalling cost across IPC boundaries come into play in every single possible situation regardless of language. It is why shared memory architectures exist. It doesn't matter what language is on the other side of the IPC, if the performance gained by using a separate process is not greater than the cost of the communication then you should avoid the IPC. One way to avoid that cost is to share the memory. In the case of code already running in a JavaScript VM a very easy way to share the memory means you do the processing in JavaScript.

That is why I am saying your evidence is a red herring. It is a case where a reasonable decision was made to rewrite in JavaScript/TypeScript but it has nothing to do with the merits of the language and everything to do with the environment that the entire system is running in. They even state the Rust code is fast (and undoubtedly faster than the JS version), just not fast enough to justify the IPC cost.

And it in no way applies to the point I am making, where I explicitly question "starting a new project" for example "my default assumption to use JS runtimes on the server". It's closer to a "Well, actually ..." than an attempt to clarify or provide a reasoned response.

The world is changing before our eyes. The coding LLMs we have already are good but the ones in the pipeline are better. The ones coming next year are likely to be even better. It is time to revisit our long held opinions. And in the case of "reads data from a OS socket/file-descriptor and writes data to a OS socket/file-descriptor", which is the case for a significant number of applications including web servers, I'm starting to doubt that choosing a scripting language for that task, as I once advocated, is a good plan given what I am seeing.

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Jean-Papoulos1y ago

>The main driver behind this project is that while Rust is very quick, the cost of serializing data between Rust and TypeScript is very high.

This sounds more like a "we're kinda stuck with Javascript here" situation. The team is making a compromise, can't have your cake and eat it too I guess.

_bin_1y ago

i don't think this speaks to the general reasons someone would rewrite a mid- or low-level project in a high-level language, so much as to the special treatment JS/TS get. yes, your data model being the default supported, and everything else in the world having to serialize/deserialize to accommodate that, slows performance. in other words, this is just a reason to use the natively-supported JS/TS, still very much the favorite children of browser engines, over the still sort of hacked-in Rust.

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zoogeny1y ago

throwitaway1123OP1y ago

> First, they are using WASM which itself is a a low-level representation.

> As for the "compilers are special" reasoning, I don't ascribe to it.

> The old cases I would choose the scripting language (familiarity, speed of adding new features, ability to hire a team quickly) seem to be eroding in the face of LLMs.

[1] https://www.prisma.io/blog/from-rust-to-typescript-a-new-cha...

zoogeny1y ago

3 more replies

Jean-Papoulos1y ago

>The main driver behind this project is that while Rust is very quick, the cost of serializing data between Rust and TypeScript is very high.

This sounds more like a "we're kinda stuck with Javascript here" situation. The team is making a compromise, can't have your cake and eat it too I guess.

_bin_1y ago

j / k navigate · click thread line to collapse