class RDoc::Comment

def extract_call_seq method
  # we must handle situations like the above followed by an unindented first
  # comment.  The difficulty is to make sure not to match lines starting
  # with ARGF at the same indent, but that are after the first description
  # paragraph.
  if @text =~ /^\s*:?call-seq:(.*?(?:\S).*?)^\s*$/m then
    all_start, all_stop = $~.offset(0)
    seq_start, seq_stop = $~.offset(1)
    # we get the following lines that start with the leading word at the
    # same indent, even if they have blank lines before
    if $1 =~ /(^\s*\n)+^(\s*\w+)/m then
      leading = $2 # ' *    ARGF' in the example above
      re = %r%
        \A(
           (^\s*\n)+
           (^#{Regexp.escape leading}.*?\n)+
          )+
        ^\s*$
      %xm
      if @text[seq_stop..-1] =~ re then
        all_stop = seq_stop + $~.offset(0).last
        seq_stop = seq_stop + $~.offset(1).last
      end
    end
    seq = @text[seq_start..seq_stop]
    seq.gsub!(/^\s*(\S|\n)/m, '\1')
    @text.slice! all_start...all_stop
    method.call_seq = seq.chomp
  elsif @text.sub!(/^\s*:?call-seq:(.*?)(^\s*$|\z)/m, '') then
    seq = $1
    seq.gsub!(/^\s*/, '')
    method.call_seq = seq
  end
  method
end