Project

General

Profile

Feature #9451

Refinements and unary & (to_proc)

Added by Jan Lelis over 2 years ago. Updated 9 months ago.

Status:
Assigned
Priority:
Normal
[ruby-core:60109]

Description

Not sure if this is a bug or feature request:

require 'minitest/autorun'
require 'set'

module ClassToProc
  refine Class do
    def to_proc
      lambda{ |*args| self.new(*args) }
    end
  end
end

using ClassToProc

describe 'Class#to_proc' do
  it 'works when called directly' do
    Set.to_proc[[1,2]].must_equal Set[1,2]
  end

  it 'fails when called via ampersand' do
    [[1,2]].map(&Set).must_equal [Set[1,2]]
  end
end

The second example errors with NoMethodError: super: no superclass method `to_proc' for Set:Class

Would be great to have it, though.


Related issues

Duplicated by Ruby trunk - Feature #12638: Symbol#to_proc probable bug (seems not to support refinements) Open

History

#1 [ruby-core:60187] Updated by Yukihiro Matsumoto over 2 years ago

  • Assignee set to Shugo Maeda

As #=== from case statement and #each from for statement, I think refinement should be effective to methods that called implicitly. Let us discuss about the issue.

Matz.

#2 [ruby-core:60193] Updated by Shugo Maeda over 2 years ago

  • Tracker changed from Bug to Feature

Yukihiro Matsumoto wrote:

As #=== from case statement and #each from for statement, I think refinement should be effective to methods that called implicitly. Let us discuss about the issue.

What do you think of other implicit conversions such as to_a called by the splat operator.

#3 [ruby-core:60414] Updated by Shugo Maeda over 2 years ago

  • Category set to core
  • Status changed from Open to Assigned
  • Assignee changed from Shugo Maeda to Yukihiro Matsumoto
  • Target version set to current: 2.2.0

I'd like to clarify the design policy rather than adding features ad hoc.

All implicit method calls in syntactic constructs should be affected by refinements, right?
Do other implementers, especially JRuby people, accept this policy?

#4 [ruby-core:62859] Updated by Nobuyoshi Nakada about 2 years ago

  • Description updated (diff)

IMHO, splat should be affected by refinements, because there is no intermediate method calls.

#5 [ruby-core:71849] Updated by Colin Fulton 9 months ago

Is there any update on this feature? In Ruby 2.2.3 I still run into a problem where the unary & can not be used when the method was added with a refinement, such as the following:

module Example
  refine String do
    def pugs
      "Pugs!"
    end
  end
end

using Example

('a'..'z').map(&:pugs)

I can understand why they currently do not work, but it leads to uglier code.

Cheers!

#6 [ruby-core:72058] Updated by Colin Fulton 9 months ago

Sorry, just saw that issue 9786 is equivalent to this one and was marked as rejected. Thanks!

#7 Updated by Nobuyoshi Nakada 26 days ago

  • Duplicated by Feature #12638: Symbol#to_proc probable bug (seems not to support refinements) added

Also available in: Atom PDF