From: "schneems (Richard Schneeman)" <richard.schneeman@...>
Date: 2012-11-10T07:58:44+09:00
Subject: [ruby-core:49180] [ruby-trunk - Feature #7314] Convert Proc to Lambda doesn't work in MRI


Issue #7314 has been updated by schneems (Richard Schneeman).


=begin
I would like a standard way to turn a Proc into a lambda even if it cannot be achieved through (({lambda(&proc)})). I don't know if it will affect the outcome, but jRuby correctly returns a lambda from (({lambda(&proc)})) in 1.9 mode.
=end
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Feature #7314: Convert Proc to Lambda doesn't work in MRI
https://bugs.ruby-lang.org/issues/7314#change-32726

Author: schneems (Richard Schneeman)
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 


=begin

I have code where I need to convert a proc to a lambda (i need to be able to return out of the block). I would expect that passing a proc into a lambda to return a lambda. When I run this code on MRI i do not get the result I would expect

 my_proc = proc { |x| x }
 my_lambda = lambda &my_proc
 my_lambda.lambda?

The result is (({false})) but I would expect it to be  (({true}))

There is currently a way to turn a proc into a lambda in MRI like this: 

  def convert_to_lambda &block
    obj = Object.new
    obj.define_singleton_method(:_, &block)
    return obj.method(:_).to_proc
  end

But this feels like a hack, and is not supported across other implementations. I would expect that passing a proc into a lambda to return a lambda, I believe it is a bug.

=end




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