Hacker News Reader

The main reason to write a new Lisp compiler based on LLVM was the full integration with the hundred of thousands c++ lines of code he previously wrote.

View on HN

What does "full integration" mean, and why couldn't that be achieved with some macros? He already showed how he used macros to achieve nice integration with LLVM (written in C++) for his interpreter.

Worst case, you'd have to write a name mangler, to teach your FFI about C++ symbols, but I imagine that would be at least an order of magnitude easier than an entire compiler (150K lines C++, 85K lines CL).

FFI is very slow. He probably needs C++ calls in hot loops.

There's a lot more to it. You need to translate native objects to and from C++ objects efficiently. You need to work with C++ exception handling to unwind the stack without clobbering RAII.

Reply on news.ycombinator.com