Fixing squiggly heredoc on Pygments

ruby_squiggly_heredoc.patch

*** pygments/lexers/ruby.old	2017-07-25 22:03:14.847653103 -0400
--- pygments/lexers/ruby.py	2017-07-25 22:38:27.475907303 -0400
***************
*** 44,49 ****
--- 44,52 ----
      def heredoc_callback(self, match, ctx):
          # okay, this is the hardest part of parsing Ruby...
          # match: 1 = <<-?, 2 = quote? 3 = name 4 = quote? 5 = rest of line
+         #
+         # Ruby >=2.3 has squiggly heredoc
+         # match: 1 = <<~?, 2 = quote? 3 = name 4 = quote? 5 = rest of line
  
          start = match.start(1)
          yield start, Operator, match.group(1)        # <<-?
***************
*** 53,59 ****
  
          heredocstack = ctx.__dict__.setdefault('heredocstack', [])
          outermost = not bool(heredocstack)
!         heredocstack.append((match.group(1) == '<<-', match.group(3)))
  
          ctx.pos = match.start(5)
          ctx.end = match.end(5)
--- 56,62 ----
  
          heredocstack = ctx.__dict__.setdefault('heredocstack', [])
          outermost = not bool(heredocstack)
!         heredocstack.append(((match.group(1) == '<<-' or match.group(1) == '<<~'), match.group(3)))
  
          ctx.pos = match.start(5)
          ctx.end = match.end(5)
***************
*** 251,256 ****
--- 254,264 ----
               heredoc_callback),
              # empty string heredocs
              (r'(<<-?)("|\')()(\2)(.*?\n)', heredoc_callback),
+             # squiggly heredocs, Ruby >=2.3
+             (r'(?<!\w)(<<~?)(["`\']?)([a-zA-Z_]\w*)(\2)(.*?\n)',
+              heredoc_callback),
+             # empty string squiggly heredocs, Ruby >2.3
+             (r'(<<~?)("|\')()(\2)(.*?\n)', heredoc_callback),
              (r'__END__', Comment.Preproc, 'end-part'),
              # multiline regex (after keywords or assignments)
              (r'(?:^|(?<=[=<>~!:])|'