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Brimstone: ES2025 JavaScript engine written in Rust

(github.com)
239 points ivankra | 1 comments | 16 Nov 25 11:41 UTC | HN request time: 0s | source
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bcardarella ◴[16 Nov 25 14:54 UTC] No.45945551[source]▶
Just a small comparison, compiled for release:

Boa: 23M Brimstone: 6.3M

I don't know if closing the gap on features with Boa and hardening for production use will also bloat the compilation size. Regardless, for passing 97% of the spec at this size is pretty impressive.

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jerf ◴[16 Nov 25 15:22 UTC] No.45945748[source]▶
It looks like Boa has Unicode tables compiled inside of itself: https://github.com/boa-dev/boa/tree/main/core/icu_provider

Brimstone does not appear to.

That covers the vast bulk of the difference. The ICU data is about 10.7MB in the source (boa/core/icu_provider) and may grow or shrink by some amount in the compiling.

I'm not saying it's all the difference, just the bulk.

There's a few reasons why svelte little executables with small library backings aren't possible anymore, and it isn't just ambient undefined "bloat". Unicode is a big one. Correct handling of unicode involves megabytes of tables and data that have to live somewhere, whether it's a linked library, compiled in, tables on disks, whatever. If a program touches text and it needs to handle it correctly rather than just passing it through, there's a minimum size for that now.

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HansHalverson ◴[16 Nov 25 18:48 UTC] No.45947379[source]▶
Brimstone does embed Unicode tables, but a smaller set than Boa embeds: https://github.com/Hans-Halverson/brimstone/tree/master/icu.

Brimstone does try to use the minimal set of Unicode data needed for the language itself. But I imagine much of the difference with Boa is because of Boa's support for the ECMA-402 Internationalization API (https://tc39.es/ecma402/).

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nekevss ◴[16 Nov 25 19:24 UTC] No.45947661[source]▶
Yeah, the majority of the difference is from the Unicode data for Intl along with probably the timezone data for Temporal.
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nicoburns ◴[16 Nov 25 20:11 UTC] No.45948009[source]▶
Is it possible to build Boa without these APIs?
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1. nekevss ◴[17 Nov 25 05:13 UTC] No.45950999{3}[source]▶
For the engine, the answer is yes, Intl and Temporal are feature flagged due to the dependencies. What I suspect they’re comparing above is the CLIs, which is completely different than the engine. I’d have to double check for the CLI. If I recall correctly, we include all features in the CLI by default.