legacy_index_name

# File activerecord/lib/active_record/migration/compatibility.rb, line 38
            def legacy_index_name(table_name, options)
              if Hash === options
                if options[:column]
                  "index_#{table_name}_on_#{Array(options[:column]) * '_and_'}"
                elsif options[:name]
                  options[:name]
                else
                  raise ArgumentError, "You must specify the index name"
                end
              else
                legacy_index_name(table_name, index_name_options(options))
              end
            end