source: EcnlProtoTool/trunk/mruby-2.1.1/lib/mruby-core-ext.rb@ 439

autoload :Pathname, 'pathname'

class Object
  class << self
    def attr_block(*syms)
      syms.flatten.each do |sym|
        class_eval "def #{sym}(&block);block.call(@#{sym}) if block_given?;@#{sym};end"
      end
    end
  end
end

class String
  def relative_path_from(dir)
    Pathname.new(File.expand_path(self)).relative_path_from(Pathname.new(File.expand_path(dir))).to_s
  end

  def relative_path
    relative_path_from(Dir.pwd)
  end
end

def _pp(cmd, src, tgt=nil, options={})
  return if Rake.verbose

  width = 5
  template = options[:indent] ? "%#{width*options[:indent]}s %s %s" : "%-#{width}s %s %s"
  puts template % [cmd, src, tgt ? "-> #{tgt}" : nil]
end