module Rake class Scope < LinkedList # Path for the scope. def path map { |item| item.to_s }.reverse.join(":") end # Path for the scope + the named path. def path_with_task_name(task_name) "#{path}:#{task_name}" end # Trim +n+ innermost scope levels from the scope. In no case will # this trim beyond the toplevel scope. def trim(n) result = self while n > 0 && ! result.empty? result = result.tail n -= 1 end result end # Scope lists always end with an EmptyScope object. See Null # Object Pattern) class EmptyScope < EmptyLinkedList @parent = Scope def path "" end def path_with_task_name(task_name) task_name end end # Singleton null object for an empty scope. EMPTY = EmptyScope.new end end