## A nice, sturdy wall to put our bottles on
def_slotted_exemplar(:wall, { {:num_bottles,   _unset},
			      {:start_bottles, _unset}}, {})
$

## The number of bottles we started with
wall.define_slot_access(:start_bottles, :writable, :private)
$

## The number of bottles we have left
wall.define_slot_access(:num_bottles, :writable, :private)
$

_method wall.new(start_bottles)

	## Create a new wall with START_BOTTLES of beer sitting on it
	
	>> _clone.init(start_bottles)
_endmethod
$

_private _method wall.init(start_bottles)

	## Initialise the amount of beer to START_BOTTLES
	
	_self.num_bottles << _self.start_bottles << start_bottles

	>> _self  
_endmethod
$

_private _method wall.no_beer?
	
	## Are there any bottles of beer left?
	
	>> _self.num_bottles < 1
_en