Ideally we'll just be able to open source it soon!
Basically we have a nice Haskell DSL for generating arbitrary C++, and we deal with lots of code you wouldn't want to write by hand (big nested switch statements and other kinds of state-machine logic, choices about loop unrolling, lots of template overloads, SIMD intrinsics that require immediate values, etc. etc.) so we write Haskell that generates C++ and feeds it to e.g. `clang`.
Some of this is directly in Haskell, and some of it is little compilers mostly done using Megaparsec. It's a really nice approach where it fits!
Basically we have a nice Haskell DSL for generating arbitrary C++, and we deal with lots of code you wouldn't want to write by hand (big nested switch statements and other kinds of state-machine logic, choices about loop unrolling, lots of template overloads, SIMD intrinsics that require immediate values, etc. etc.) so we write Haskell that generates C++ and feeds it to e.g. `clang`.
Some of this is directly in Haskell, and some of it is little compilers mostly done using Megaparsec. It's a really nice approach where it fits!