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What parameters for inline block (<< - BLOCK, param1, param2) mean?

I am reading some source code https://github.com/plataformatec/devise and found that the line of code is:

class_eval <<-URL_HELPERS, __FILE__, __LINE__ + 1

What are the parameters __FILE__

and __LINE__ + 1

to block the ad (which changes with respect to the inline box without these options)?

https://github.com/plataformatec/devise/blob/master/lib/devise/controllers/url_helpers.rb#L47

thank

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2 answers


These parameters are specific to class_eval , not to document here . It is generally accepted practice that an error that can raise the circled code will be shown with a link to the current file and with the correct line number.



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As an alternative example showing how HEREDOCs work, I wrote in IRB the other day:

require 'nokogiri'
doc = Nokogiri.XML(<<ENDXML,&:noblanks)
  ...gobs and gobs of pasted xml...
ENDXML


Even crazier is this legal syntax for passing multiple HEREDOC lines at once:

p( <<END1, <<-END2, <<END3 )
  This indented text is part of
  the first parameter, END1
END1
And this text is part of param2
  whose ending sigil may be indented
  END2
and finally this text
is part of
the third parameter
END3
#=> "  This indented text is part of\n  the first parameter, END1\n"
#=> "And this text is part of param2\n  whose ending sigil may be indented\n"
#=> "and finally this text\nis part of\nthe third parameter\n"
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