class PrettyPrint

# File lib/prettyprint.rb, line 48
def PrettyPrint.format(output=''.dup, maxwidth=79, newline="\n", genspace=lambda {|n| ' ' * n})
  q = PrettyPrint.new(output, maxwidth, newline, &genspace)
  yield q
  q.flush
  output
end

# File lib/prettyprint.rb, line 85
def initialize(output=''.dup, maxwidth=79, newline="\n", &genspace)
  @output = output
  @maxwidth = maxwidth
  @newline = newline
  @genspace = genspace || lambda {|n| ' ' * n}

  @output_width = 0
  @buffer_width = 0
  @buffer = []

  root_group = Group.new(0)
  @group_stack = [root_group]
  @group_queue = GroupQueue.new(root_group)
  @indent = 0
end

# File lib/prettyprint.rb, line 62
def PrettyPrint.singleline_format(output=''.dup, maxwidth=nil, newline=nil, genspace=nil)
  q = SingleLine.new(output)
  yield q
  output
end

# File lib/prettyprint.rb, line 163
def break_outmost_groups
  while @maxwidth < @output_width + @buffer_width
    return unless group = @group_queue.deq
    until group.breakables.empty?
      data = @buffer.shift
      @output_width = data.output(@output, @output_width)
      @buffer_width -= data.width
    end
    while !@buffer.empty? && Text === @buffer.first
      text = @buffer.shift
      @output_width = text.output(@output, @output_width)
      @buffer_width -= text.width
    end
  end
end

# File lib/prettyprint.rb, line 227
def breakable(sep=' ', width=sep.length)
  group = @group_stack.last
  if group.break?
    flush
    @output << @newline
    @output << @genspace.call(@indent)
    @output_width = @indent
    @buffer_width = 0
  else
    @buffer << Breakable.new(sep, width, self)
    @buffer_width += width
    break_outmost_groups
  end
end

# File lib/prettyprint.rb, line 158
def current_group
  @group_stack.last
end

# File lib/prettyprint.rb, line 215
def fill_breakable(sep=' ', width=sep.length)
  group { breakable sep, width }
end

# File lib/prettyprint.rb, line 291
def flush
  @buffer.each {|data|
    @output_width = data.output(@output, @output_width)
  }
  @buffer.clear
  @buffer_width = 0
end

# File lib/prettyprint.rb, line 252
def group(indent=0, open_obj='', close_obj='', open_width=open_obj.length, close_width=close_obj.length)
  text open_obj, open_width
  group_sub {
    nest(indent) {
      yield
    }
  }
  text close_obj, close_width
end

# File lib/prettyprint.rb, line 263
def group_sub
  group = Group.new(@group_stack.last.depth + 1)
  @group_stack.push group
  @group_queue.enq group
  begin
    yield
  ensure
    @group_stack.pop
    if group.breakables.empty?
      @group_queue.delete group
    end
  end
end

# File lib/prettyprint.rb, line 280
def nest(indent)
  @indent += indent
  begin
    yield
  ensure
    @indent -= indent
  end
end

# File lib/prettyprint.rb, line 183
def text(obj, width=obj.length)
  if @buffer.empty?
    @output << obj
    @output_width += width
  else
    text = @buffer.last
    unless Text === text
      text = Text.new
      @buffer << text
    end
    text.add(obj, width)
    @buffer_width += width
    break_outmost_groups
  end
end