> Bun.js uses the JavaScriptCore engine, which tends to start and perform a little faster than more traditional choices like V8
So it isn't really everything written in Zig and there is some C++ helping there, actually.
So it isn't really everything written in Zig and there is some C++ helping there, actually.
The fact it states it's powered by JSC before even mentioning Zig makes it pretty clear, imo.
Using the same reasoning I can assert having written a JavaScript runtime in e.g. F# by making use of C++/CLI to compile JSC.
They don't claim it's pure Zig and even mention JavaScriptCore in their front page.
Definitely reads otherwise and is click bait, given the actual implementation.
If you read "runtime" as "extensions that allow you to do actually useful stuff" instead of "parser/evaluator", I don't see an issue.
There is precedent for this too -- for instance, the ".NET runtime" is not only the JIT/AOT compiler for CIL, but also the libraries providing the .net api + standards/mechanisms for loading other libraries, etc.
See also https://stackoverflow.com/questions/3900549/what-is-runtime :
> Runtime describes software/instructions that are executed while your program is running, especially those instructions that you did not write explicitly, but are necessary for the proper execution of your code. [...] Runtime code is specifically the code required to implement the features of the language itself.