[ddlm-group] _enumerated_set.table_id

Dear DDLm group,

(originally sent Feb 5th)

I have been going through ddl.dic with an eye to writing automated dictionary checking routines and came across _enumerated_set.table_id.  This attribute is used precisely once in all the draft DDLm dictionaries (which include all of the previous DDL1 dictionaries): and that is in ddl.dic itself in the definition for the DDLm _import.get attribute.   This attribute is intended to specify in a machine-readable way the possible values of CIF2 Table keys. In this particular case the CIF2 tables are themselves within a List:

    _type.purpose                Import
    _type.source                 Assigned
    _type.container              List
    _type.contents               Table(Code)
    _type.dimension              [{}]
    loop_
    _enumeration_set.state
    _enumeration_set.detail
    _enumeration_set.table_id
              1             'filename/URI of source dictionary'      file     
              2             'save framecode of source definition'    save     
              3             'mode for including save frames'         mode     
              4             'option for duplicate entries'   dupl   
              5             'option for missing duplicate entries'   miss
    loop_
    _method.purpose
    _method.expression
     Evaluation   
;
     With  i  as  import

    _import.get = [{"file":i.file_id, "save":i.frame_id, "mode":i.mode,
                    "dupl":i.if_dupl, "miss":i.if_miss}]
;


Because it is in the _enumerated_set category, the category key _enumerated_set.state must be present when listing these table keys, but instead of _enumerated_set.state listing the actual permitted values, it contains meaningless dummy values; table_id then lists table keys, not values, and so the restraints on the values of the keys are absent.  This looks like an abuse of the enumerated_set category when the natural solution as proposed by Doug du Boulay is to simply enhance _type.contents, i.e.