Hello john, Thank you very much prompt solution. You are correct I map the errorId and cause. They I try to operations on those structures. I feel the built in TYPE-IDENTIFER would not suit for my requirement. I may try the second solution that you suggetsed to have one table.
Warm regards, Vasa -----Original Message----- From: John Larmouth [mailto:[EMAIL PROTECTED]] Sent: Tuesday, July 09, 2002 6:39 PM To: [EMAIL PROTECTED] Subject: Re: [ASN.1] Question on XER encoding of SEQUENCE OF element types Maybe my last answer was not so good! It was factually correct, and the minimum change. However, I think the spirit of your example is that the type filling the ANY is fully determined by the value of errorId. Yes? In that case, you would be better to use the built-in class TYPE-IDENTIFIER, which has two fields, an &id field that is an OID that identifies the type in the ANY, and an &Type field that defines the type for that OID. This would give you: XXArg ::= SEQUENCE { errorId TYPE-IDENTIFIER.&id, cause TYPE-IDENTIFIER.&Type OPTIONAL} You can then (but need not!) go on to specify that the cause is determined by the errorId using a Table which gives OID values and corresponding types (a set of objects of class TYPE-IDENTIFIER): XXArg ::= SEQUENCE { errorId TYPE-IDENTIFIER.&id ({Table}), cause TYPE-IDENTIFIER.&Type ({Table} {@erroId} )OPTIONAL} There is then the question of whether the types and OID values are specified (or partly specified) in your standard. If they are wholly implementation-dependent, then you need: Table ::= { ... } to indicate that Table is not standardised, and that tools need to invoke some run-time procedures to find out what id values and what corresponding types a particular implementation supports. Finally (if you are still reading this!), it may be that your "Error" type is in fact an INTEGER (or even something more complicated, giving severity as well as an id) rather than an Object Identifier. In this case, you will need to define your own class instead of using the built-in TYPE-IDENTIFIER class, but the principles above still stand. John L
