Forum: Ruby-core [ruby-trunk - Bug #8136][Open] gsub strange behavior when substituting "\\'"

Issue #8136 has been reported by alexeymuranov (Alexey Muranov).

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Bug #8136: gsub strange behavior when substituting "\\'"
https://bugs.ruby-lang.org/issues/8136

Author: alexeymuranov (Alexey Muranov)
Status: Open
Priority: Normal
Assignee:
Category:
Target version:
ruby -v: 2.0.0


=begin
  s = "\\'"          # => "\\'"
  print s            # \'
  "foo".gsub("f", s) # => "oooo"

Can anybody please explain to me why it works like this?  Is this a bug?
=end

Issue #8136 has been updated by Eregon (Benoit Daloze).


Seems like \' is interpreted as $' ($POSTMATCH) which is in this case 
'oo'.
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Bug #8136: gsub strange behavior when substituting "\\'"
https://bugs.ruby-lang.org/issues/8136#change-37792

Author: alexeymuranov (Alexey Muranov)
Status: Open
Priority: Normal
Assignee:
Category:
Target version:
ruby -v: 2.0.0


=begin
  s = "\\'"          # => "\\'"
  print s            # \'
  "foo".gsub("f", s) # => "oooo"

Can anybody please explain to me why it works like this?  Is this a bug?
=end

Issue #8136 has been updated by nobu (Nobuyoshi Nakada).

Category set to doc
Status changed from Open to Closed

This is one of most frequently asked questions.
Though I can't remember a pointer to good explanation, someone would 
know it.
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Bug #8136: gsub strange behavior when substituting "\\'"
https://bugs.ruby-lang.org/issues/8136#change-38059

Author: alexeymuranov (Alexey Muranov)
Status: Closed
Priority: Normal
Assignee:
Category: doc
Target version:
ruby -v: 2.0.0


=begin
  s = "\\'"          # => "\\'"
  print s            # \'
  "foo".gsub("f", s) # => "oooo"

Can anybody please explain to me why it works like this?  Is this a bug?
=end

Issue #8136 has been updated by alexeymuranov (Alexey Muranov).


Excuse me, nobu, i have not understood, how can i replace something with 
a backslash followed by single quote?
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Bug #8136: gsub strange behavior when substituting "\\'"
https://bugs.ruby-lang.org/issues/8136#change-38062

Author: alexeymuranov (Alexey Muranov)
Status: Closed
Priority: Normal
Assignee:
Category: doc
Target version:
ruby -v: 2.0.0


=begin
  s = "\\'"          # => "\\'"
  print s            # \'
  "foo".gsub("f", s) # => "oooo"

Can anybody please explain to me why it works like this?  Is this a bug?
=end

Issue #8136 has been updated by nobu (Nobuyoshi Nakada).


You need more escapes.

  "foo".gsub("f", "\\\\'")
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Bug #8136: gsub strange behavior when substituting "\\'"
https://bugs.ruby-lang.org/issues/8136#change-38077

Author: alexeymuranov (Alexey Muranov)
Status: Closed
Priority: Normal
Assignee:
Category: doc
Target version:
ruby -v: 2.0.0


=begin
  s = "\\'"          # => "\\'"
  print s            # \'
  "foo".gsub("f", s) # => "oooo"

Can anybody please explain to me why it works like this?  Is this a bug?
=end

Issue #8136 has been updated by alexeymuranov (Alexey Muranov).


nobu (Nobuyoshi Nakada) wrote:
> =begin
> You need more escapes.
>
>   "foo".gsub("f", "\\\\'")
> =end

Thank you, i have not read the documentation carefully.  It is still a 
bit strange to me that a replacement string is not taken literally by 
default.
----------------------------------------
Bug #8136: gsub strange behavior when substituting "\\'"
https://bugs.ruby-lang.org/issues/8136#change-38081

Author: alexeymuranov (Alexey Muranov)
Status: Closed
Priority: Normal
Assignee:
Category: doc
Target version:
ruby -v: 2.0.0


=begin
  s = "\\'"          # => "\\'"
  print s            # \'
  "foo".gsub("f", s) # => "oooo"

Can anybody please explain to me why it works like this?  Is this a bug?
=end