Comment by robmccoll | Hacker News Reader

Comment by robmccoll | Hacker News Reader

Python as a language will likely never have a "fast" implementation and still be Python. It is way too dynamic to be predictable from the code alone or even an execution stream in a way that allows you to simplify the actual code that will be executed at runtime either through AOC or JIT. The language is itself is also quite large in terms of syntax and built-in capability at this point which makes new feature-conplete implementations that don't make major trade offs quite challenging. Given how capable LLMs are at translating code, it seems like the perfect time to build a language with similar syntax, but better scoped behavior, stricter rules around typing, and tooling to make porting code and libraries automated and relatively painless. What would existing candidates be and why won't they work as a replacement?

The secret as stated is the comlexity of a JIT. In practice, that dynamism just isn't used much in practice and in particular in optimization targets. The JIT analyses the code paths, sees that no writes to the target are possible so treats it as a constant.

Java has similar levels of dynamism-with invokedynamic especially, but already with dynamic dispatch-in practice the JIT monomorphises to a single class even though by default classes default to non-final in Java and there may even be multiple implementations known to the JVM when it monomorphises. Such is the strength of the knowledge that a JIT has compared to a local compiler.

Yes, Java syntax might look like C++, but the execution semantics are closer to Objective-C and Smalltalk, which is why adopting StrongTalk JIT for Java Hotspot was such a win.

Pypy is 10x faster and is compatible with most cpython code. IMHO it was a big mistake not to adopt JIT during the 2-to-3 transition.

That “most” is doing a big lift there. At some point you might consider that you’re actually programming in the language of Pypy and not pure Python. It’s effectively a dialect of the language like Turbo Pascal vs ISO Pascal or RPerl instead of Perl.

Most is more CPython code than python 3 was compatible with. But the port of the broken code was likely much easier than if it had moved to a JIT at the same time too.

Isn't there an incoming JIT in 3.14?

Self and Smalltalk enter the room.

As for the language with similar syntax, do you want Nim, Mojo or Scala 3?

Reply on news.ycombinator.com