Fiber#alive? not defined

Question

I use ruby1.9.2p180 (2011-02-18 revision 30909) i686-linux. Fiber#alive? returns an undefined error:

fiber = Fiber.new{puts 'hello'}
fiber.alive?
=> undefined error

Other methods, for example, Fiber#resume , Fiber.yield seem to be working fine. What is wrong?

By the way, what is the difference between Fiber#resume and Fiber#transfer?

score 4 · Accepted Answer · answered Mar 16 '11 at 16:51

4

You forgot to require 'fiber' first:

f = Fiber.new { puts 'hello' }
  => #<Fiber:0x896109c> 

f.alive?
  # NoMethodError: undefined method `alive?' for #<Fiber:0x896109c>
  #      from (irb):2
  #      from /home/johnf/.rvm/rubies/ruby-1.9.2-rc1/bin/irb:17:in `<main>'

require 'fiber'
  => true 

f.alive?
  => true

answered Mar 16 '11 at 16:51

John Feminella

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2

Thanks. I didn't forget it, I didn't know it. It didn't say so in the doc. Its says you need to do that for `Fiber.current`, but it doesn't say so for `Fiber#alive?`. – sawa Mar 16 '11 at 16:55
Probably a documentation oversight, then. When in doubt, read the code. :) – John Feminella Mar 16 '11 at 16:57
2

So requiring fiber is only required for some, not all of Fiber's methods? – Andrew Grimm Mar 16 '11 at 22:40
1

@Andrew That seems to be the case. As far as I checked on my irb, `.new`, `.yield`, `#resume` don't require `require`. `.current`, `#alive?`, `#transfer` do. – sawa Mar 17 '11 at 01:45

Fiber#alive? not defined

1 Answers1