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Feature #9098

closed

Indent heredoc against the left margin by default when "indented closing identifier" is turned on.

Added by sikachu (Prem Sichanugrist) over 7 years ago. Updated over 5 years ago.

Status:
Closed
Priority:
Normal
Target version:
-
[ruby-core:58243]

Description

tl;dr: I would like to port +String#strip_heredoc+ (http://api.rubyonrails.org/classes/String.html#method-i-strip_heredoc) from Rails and enable it on <<- heredoc.

Hi,

I've been using here document (heredoc) for a while, and I've found out that it's very annoying that the content is always treated as flushed left. Per syntax doc:

Note that the while the closing identifier may be indented, the content is
always treated as if it is flush left.  If you indent the content those spaces
will appear in the output.

So, this is the current result if you use heredoc in Ruby:

class FancyHello
  def self.hello
    puts <<-README.inspect
      Hello
        World!
    README
  end
end

FancyHello.hello # => "      Hello\n        World!\n"

In Rails, the core team has implemented +String#strip_heredoc+, which handles this scenario by remove leading white spaces from the string. However, not many user know that Rails has that method, and instead doing this to get around it:

class FancyHello
  def self.hello
    puts <<-README.inspect
Hello
  World!
    README
  end
end

FancyHello.hello # => "Hello\n  World!\n"

I really think that we could do better on this by removing the leading white spaces, matching +String#strip_heredoc+ method.

So, after the change, I want to be able to do this, and get this result:

class FancyHello
  def self.hello
    puts <<-README.inspect
      Hello
        World!
    README
  end
end

FancyHello.hello # => "Hello\n  World!\n"

Note: the behavior on <<HEREDOC will stay the same, as I feel like in that case you really want the input to be flushed left.

I'll write up a patch and submit it if you think this is a good idea. Please let me know any question or concern you may have.

Thank you,

Prem


Files

dedent_heredoc.patch (12.8 KB) dedent_heredoc.patch bjmllr (Ben Miller), 11/28/2015 01:26 AM
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