# File lib/rake.rb, line 1812
1812:     def lookup(task_name, initial_scope=nil)
1813:       initial_scope ||= @scope
1814:       task_name = task_name.to_s
1815:       if task_name =~ /^rake:/
1816:         scopes = []
1817:         task_name = task_name.sub(/^rake:/, '')
1818:       elsif task_name =~ /^(\^+)/
1819:         scopes = initial_scope[0, initial_scope.size - $1.size]
1820:         task_name = task_name.sub(/^(\^+)/, '')
1821:       else
1822:         scopes = initial_scope
1823:       end
1824:       lookup_in_scope(task_name, scopes)
1825:     end