I dont think interfaces is the point. As it is now in ruby you have to pick between comfort and speed when you can have both. Continuation safety has never bee

I dont think interfaces is the point. As it is now in ruby you have to pick between comfort and speed when you can have both. Continuation safety has never been a thing in ruby, so caring about it doesn't make much sense regardless of the presence of call/cc. And lastly, neither my loops nor others I have mentioned only accumulate into lists. My loops a re in the most general sense a left fold, although right folds are possible to write as well. I provide accumulators for just about any data type available, and writing a new one yourself is pretty easy. You can express lazy loops with it as well. All without sacrificing performance. Any performance in most cases. I haven't written much ruby since the 1.9 days, but back then I remember having to rewrite the nice .each{}.blah.blah into for loops. I could prototype in a nice way which was nice, but in the code I ended up shipping I had to juggle state using for loops because the thing I prototyped ended up being a bit slow. I use map, filter and friends in scheme all the time, but when those are insufficient or too slow I don't have to resort to named lets. I can just use the loop macro which compiles to a named let.