G'day,
Ramaswamy wrote:
I have been going thru the ITU-T doc on parameterization and the following seemed unclear to me. It is stated that in a ParameterList the DummyReference may stand for a "Type" or "DefinedObjectClass". But since DefinedObjectClass also includes UsefulObjectClassReference (TYPE-IDENTIFIER and ABSTRACT-SYNTAX), does this imply that occurrences of these in the scope of the parameterized entity must be replaced by the actual parameter? Please provide more clarity on this. Bye.
It would help if you could post an example of what you mean, but I'll have a stab at it.
TYPE-IDENTIFIER is just a reference to a pre-defined class:
TYPE-IDENTIFIER ::= CLASS { &id OBJECT IDENTIFIER UNIQUE, &Type } WITH SYNTAX {&Type IDENTIFIED BY &id}
(X.681 (2002), Annex A, Sec. A.2)
This reference is available within a module without the need to import it (that is, it has pervasive scope), but is still subject to the normal scoping rules. If you redefine the name locally, then the pervasive defininition is lost.
For example:
-- redefine pervasive type TYPE-IDENTIFIER TYPE-IDENTIFIER ::= INTEGER
-- will use local definition here v TYPE-IDENTIFIER ::= 1
This is illegal, for TYPE-IDENTIFIER and ABSTRACT-SYNTAX are reserved words (see X.680, 11.27).
--
Olivier DUBUISSON
france telecom R&D
DTL/TAL - 22307 Lannion Cedex - France t: +33 2 96 05 38 50 - f: +33 2 96 05 39 45 - http://asn1.elibel.tm.fr/
