# File lib/rake.rb, line 1698
1698:     def lookup(task_name, initial_scope=nil)
1699:       initial_scope ||= @scope
1700:       task_name = task_name.to_s
1701:       if task_name =~ /^rake:/
1702:         scopes = []
1703:         task_name = task_name.sub(/^rake:/, '')
1704:       elsif task_name =~ /^(\^+)/
1705:         scopes = initial_scope[0, initial_scope.size - $1.size]
1706:         task_name = task_name.sub(/^(\^+)/, '')
1707:       else
1708:         scopes = initial_scope
1709:       end
1710:       lookup_in_scope(task_name, scopes)
1711:     end