4 ms·

function coloring is exactly the stackful/stackless division. Stackless functions can't be called from a stackful function without special ceremony

• littlestymaar 3y ago
  This “ceremony” as you call it can totally be handled by the compiler, the same way the compiler deals with the unwinding ceremony without you ever knowing about it. The only reason why we ask the programmer to do it by themselves, is because explicitness is favored. This is exactly the same reasoning as the difference between Rust's `Result` and C++ exceptions. They serve the same purpose, they spread into the code base the same way (if on of the function you transitively call can raise an exception, you can raise an exception) but in one case we ask the programmer to to the bookkeeping manually so that it's explicit when reading the code. The only meaningful difference between stackful and stackless coroutines is the ability to write recursive function call. If your coroutines are stackless you need to box to avoid the sizedness issue, but in practice it's only marginally different from segmented stacks. If you have a moving GC and can just relocate the stack then you performance in case of recursive function call will be better, but it's also true about boxing if you have a generational collector with bump allocation. So this is mostly a difference of GC vs no-GC, in a situation where GC is actually improving performance characteristics.