# File lib/maruku/input/extensions.rb, line 49
  def check_block_extensions(src, con, line)
    BlockExtensions.each do |reg, block|
      if reg.match(line)
        block = BlockExtensions[reg]
        accepted =  block.call(doc, src, con)
        return true if accepted
      end
    end
    false # not special
  end