From: David Flanagan <david@...>
Date: 2007-08-23T05:55:50+09:00
Subject: Re: coroutines with Fiber::Core

SASADA Koichi wrote:
> Hi,
> 
> David Flanagan wrote:
>> f.transfer(100)
> 
> Fiber::Core and Fiber::Core#transfer is black magic.  So I'm
> planning to rename this class and method to
> Fiber::DangerousCore::__unsafe_transfer__I_cant_promise_your_program_run_correctly__!

I like that method name!  :-)

Why expose Fiber::Core if it is so dangerous?  Are there scenarios where 
it can be used safely?


> 
> These method names (resume/yield) are from Lua.  "transfer" is from
> Modula-2.  "double resume error" is from Python's generator.

Thanks. These were enough hints for me to figure it out.  Here's the 
Fibonnaci sequence:

fib = Fiber.new do
   x, y = 0, 1
   loop do
     Fiber.yield y
     x,y = y,x+y
   end
end

20.times { puts fib.resume }

> BTW, I'm thinking about name "Fiber".  Current Fiber means
> Semi-Coroutine.  Fiber::Core is Coroutine.  Yes, name of Fiber is
> from Microsoft, but it's means Semi-Coroutine such as Lua's
> coroutine and Python's generator.

How about just calling it a Coroutine?  Lua uses coroutine even though 
it is not a full coroutine.  I'd be more concerned about the method name 
yield: Fiber.yield is superficially similar, but deeply different from a 
regular ruby yield, and I think this could cause confusion.  How about 
using Fiber.return or even Fiber.coreturn?

	David