Feature #8572: Fiber should be a Enumerable

• Status: Closed
• Assignee: ko1 (Koichi Sasada)
• Target version: 2.6

[mattn (Yasuhiro Matsumoto)]

I'm thinking that Fiber should be a Enumerable. it's easy and reasonable to implement.

https://gist.github.com/mattn/5874949

[matz (Yukihiro Matsumoto)]

I think this is a good idea, and since it's a mere addition, we don't have to worry about compatibility.

Matz.

[ko1 (Koichi Sasada)]

• Assignee set to ko1 (Koichi Sasada)

Use case?

[mattn (Yasuhiro Matsumoto)]

ko1 (Koichi Sasada) wrote:

Use case?

f = Fiber.new {
  Fiber.yield 3
  Fiber.yield 2
  Fiber.yield 1
  Fiber.yield 0
}

f.each do |x|
  puts x
end

For example, I want to do each for Fiber. But it can't

[zzak (zzak _)]

You could always included Enumerable in your class that implements Fiber and define #each

[zzak (zzak _)]

Sorry, I missed your gist orz

[knu (Akinori MUSHA)]

We have Generator in 1.8 and Enumerator in 1.9+ that work exactly the
same as the given example.

    # In ruby 1.8, require 'generator' and call Generator.new instead
    enum = Enumerator.new { |g|
      g.yield 3
      g.yield 2
      g.yield 1
      g.yield 0
    }

    # internal style
    enum.each do |x|
      puts x
    end

    # external style
    while enum.next?
      puts enum.next
    end

One of the reasons why Fiber was originally introduced was to
reimplement Generator of ruby 1.8 in better and faster way. Using
Fiber as implementation technique, Generator was successfully
integrated into Enumerator in Ruby 1.9.

So, Fiber is there as a low-level API for implementing Enumerator in
the first place. It does not make much sense to me to add a
non-primitive feature to Fiber just to make it work like Enumerator.

I think we need a real use case that would explain why Fiber should be
used that way.

[mattn (Yasuhiro Matsumoto)]

I think most of use case of using Fiber is something like getting stream data or catching-up draining entities. Maybe we won't use Fiber for getting limited resources. For example, If Fiber has each, I guess that we will be possible to write twitter client elegant. :)

    f = Fiber.new {
      # getting twitter status
      loop {
        Fiber.yield tweet_status
      }
    }
    
    f.each do |x|
      puts "#{x.screen_name}: #{x.text}"
    end

[matz (Yukihiro Matsumoto)]

+1

Matz.

[ko1 (Koichi Sasada)]

Why you don't use Enumerator?

 class TS
   attr_accessor :screen_name, :text
   def initialize
     @screen_name = "foo"
     @text = "sample"
   end
 end
 
 f = Enumerator.new {|g|
   # getting twitter status
   loop {
     g.yield TS.new
   }
 }
 
 f.each do |x|
   puts "#{x.screen_name}: #{x.text}"
 end

---

// SASADA Koichi at atdot dot net

[mattn (Yasuhiro Matsumoto)]

Why you don't use Enumerator?

Ah, make sense.

[ko1 (Koichi Sasada)]

• Category set to core
• Status changed from Open to Feedback
• Target version set to 2.6

Can I close it?

[mattn (Yasuhiro Matsumoto)]

Koichi Sasada wrote:

Can I close it?

Sorry for delay. Close this please.

[nobu (Nobuyoshi Nakada)]

• Status changed from Feedback to Closed