[anonymoushn]

Alright. One reason for my confusion is that I assumed you would post "async functions (and generators?) are not colored functions in JavaScript" at the top level if you meant that, since the article is about async functions in JavaScript. So I wondered, what's the distinction between async functions in JavaScript and in Python that makes one "colored functions" but not the other? But this is not what you intended. Thanks for the clarification.

Some programming languages have stackless async functions and generators that work the way you said, and some other languages have stackful coroutines. In the languages I use the most, functions that switch to other parts of the program are functions (according to the type system and the calling convention, but not in the sense that they have only one entry point and one exit point and no state). This is pretty great, because things are composable in precisely the way the article complains that they are not. Given that these things exist, it's fine to say "coroutines and functions are two different things" but maybe saying "a function which jumps to a different stack and which can then be jumped back into is not a function" will just make people very confused about the whole thing.

If you have this, uh, code fragment:

  function read_five(socket)
    local data, err = socket:recv(5)
    if not err then
      return data
    end
    return nil, err
  end

perhaps we shouldn't say "the value declared by the code fragment is a function or is not a function depending on whether recv nonlocally switches only to the kernel or whether it can also switch to an event loop in the same process"