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giancarlostoro | on: LLMs are making formal software verification feasible at a much larger scale
Hmm? I had Claude Opus 4.6 implement a .NET compiled language that is Python-like (we already have IronPython, I wanted something Python-like that treated .NET as its entire runtime) language in about two (maybe three sessions tops?) of 1M token context windows, and the first two times I only used roughly 400 to 600k tokens? When Anthropic dropped the 1M context window update, I put it to the test.

See for yourself:

https://github.com/Giancarlos/Culebral

Anyway, my custom (currently paused because I'm taking on a much more ambitious compiler project with Claude... just to push the limits) language can build ASP .NET applications, and a bunch other things. I also took the Rust approach to types, all method signatures must have types defined, type hints are inferred when declaring new values from the value on the right.

I've also had Claude rewrite legacy C# projects with 100k+ lines of code, fully in Rust, long before Opus 5.0. I've spent the last year pushing the limits with Claude, including reimplementing existing software, which people are catching on to now, and I've managed to get rather far in some cases.

So I wouldn't be surprised if yes, Claude can implement Python, mind you, there's Python interpreter coded in Python in what was it? 500 lines of Python? You can build a Python stack machine bytecode interpreter in like 60 ~ 80 lines of Python code.

Would not surprise me if you can trim a C programming language interpreter down in terms of lines of code when you rewrite it in Rust especially when you have access to a much more functional language, not to mention Rust took the best bits out of OCaml it could to make itself very efficient at writing compilers / languages (so they could write their own compiler in Rust...).

I am also having Claude building me a much smaller compiler, which started out in under 500 lines of Python, but as I got more ambitious it had to write more code for my language, it was meant to be a slightly less restrictive Go, the Python basically converts the syntax to C which then compiles anywhere. Havent put that one on GitHub since I'm still tinkering with it.

anonymous908213 | parent
I notice you haven't touched that repo once since the month you prompted for it. I don't doubt that you generated some cute little prototype that compiles something. I do doubt that it's something actually suitable for anybody to use for programming. My own experiments with having frontier models attempt to implement my own language have all been dire. Even with a rigorous specification and a set of hand-written programs showing both the input of my language and the asm it should output, it managed to create something that compiles exactly those programs and completely fails in real-world use beyond that. So too with Claude's own C compiler experiment; even with C's unbelievably rigorous test suites that give it a deterministic guideline and actionable feedback every time it fucks up, it was still shit. If they merely gave it a C specification, without the decades of human-written tests, there is a snowball's chance in hell it would produce anything worth using.
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