From: Shri Borde <Shri.Borde@...>
Date: 2009-02-06T03:31:26+09:00
Subject: [ruby-core:21869] Re: What does this regexp mean - /\c#{_J}/

Ah, ok.

-----Original Message-----
From: Tomas Matousek [mailto:Tomas.Matousek@microsoft.com] 
Sent: Thursday, February 05, 2009 10:26 AM
To: ruby-core@ruby-lang.org
Subject: [ruby-core:21867] Re: What does this regexp mean - /\c#{_J}/

\c converts the following character (which happens to be # in this case) to a control character. So #{} is not treated as an expression in this case.

irb(main):001:0> "\c#{foo}"
=> "\003{foo}"

Tomas

-----Original Message-----
From: Shri Borde [mailto:Shri.Borde@microsoft.com] 
Sent: Thursday, February 05, 2009 9:55 AM
To: ruby-core@ruby-lang.org
Subject: [ruby-core:21860] Re: What does this regexp mean - /\c#{_J}/

Actually, with strings, the regexp is evaluated at the very end after substituting all the variables. So this should have actually worked. Here is the spec I will add. The not_compliant_on(:ruby) means that it is a Ruby bug

  it "allows substitution to interact with other Regexp constructs" do
    str = "foo)|(bar"
    /(#{str})/.should == /(foo)|(bar)/
    
    str = "a"
    /[#{str}-z]/.should == /[a-z]/

    not_compliant_on(:ruby) do
      str = "J"
      re = /\c#{str}/.should == /\cJ/
    end
  end  

-----Original Message-----
From: Shri Borde 
Sent: Wednesday, February 04, 2009 3:33 PM
To: ruby-core@ruby-lang.org
Subject: RE: [ruby-core:21839] Re: What does this regexp mean - /\c#{_J}/

Makes sense

-----Original Message-----
From: Charles.O.Nutter@sun.com [mailto:Charles.O.Nutter@sun.com] On Behalf Of Charles Oliver Nutter

No warnings in JRuby but we appear to do the same thing. Parser artifact 
no doubt...I'd call it a bug.

- Charlie