You could add in continuation support as well as unbounded stack size to make it even more difficult to implement efficiently. There are tricks these days for i

You could add in continuation support as well as unbounded stack size to make it even more difficult to implement efficiently. There are tricks these days for implementing continuations somewhat efficiently (and by somewhat, I mean that they're only 3-5x slower than explicit continuation passing with lambdas), but these tricks largely don't work in WASM without doing something extreme like completely ignoring the WASM stack and storing return addresses/current continuation on the WASM heap. Unbounded stack size is similarly difficult for WASM because like before, you have to be very careful about using the WASM stack. Even with C++, you basically need to drop down to intrinsics or assembly to make full use of SIMD.