[leorize]

Right now I'm cooking up an stdlib based around CPS: https://github.com/alaviss/nim-sys

The major perk is that you queue computation (read: "thread"), not callbacks, so you can write stuff like this:

    while true:
      let bytesRead = read(fd, buf, bufsize)
      if bytesRead == -1:
        if errno == EAGAIN or errno == EWOULDBLOCK:
          wait(fd, Read) # Queue this computation until the fd is readable
        else:
          raise newIOError(errno)
      else:
        return bytesRead

Even IOCP is made simple here:

    let overlapped = new Overlapped
    # <do your operation>
    if error == WSA_IO_PENDING:
      wait(handle, overlapped) # Queue this computation until the overlapped operation is complete
      if WSAGetOverlappedResult(...) == FALSE:
        raise newIOError(errno)
      else: ...

I think this kind of simplicity afforded to user code is rarely seen in most languages, which is why I decided to base my stdlib on this.