In Mr. Dubuisson's book ("ASN.1 - Communication between Heterogenous
Systems") it is suggested (page 236) that if AUTOMATIC TAGS clause is not
used in the header module, a tag of class context-specific should be
inserted before each CHOICE type. The example reads:
T ::= CHOICE { a [0] INTEGER,
b [1] NULL }
U ::= SET { x [0] REAL,
y [1] T,
z [2] CHOICE { c [1] BIT STRING,
d [2] OCTET STRING } }
If U were a SEQUENCE, I guess the correct definitions would be:
T ::= CHOICE { a [0] INTEGER,
b [1] NULL }
U ::= SEQUENCE { x [0] REAL,
y [1] T,
z [2] CHOICE { c [1] BIT STRING,
d [2] OCTET STRING } }
Does that mean that when (BER) encoding the object, the choice will have two
tags in a row: first to tell that the CHOICE is present within its parent
SET or SEQUENCE type and the second to indicate which is the chosen
object/type inside the CHOICE?
Regards,
Eddie L
Eddie Lascu
Senior Software Developer, Associate
IBI Group
230 Richmond St. W., 5th Floor
Toronto ON M5V 1V6
Tel. (416) 596-1930 x312
Fax. (416) 596-0644
www.ibigroup.com
NOTE: This e-mail message and attachments may contain privileged and
confidential information. If you have received this message in error,
please immediately notify the sender and delete this e-mail message.
"NOTE: Ce courriel peut contenir de l'information privil�gi�e et
confidentielle. Si vous avez re�u ce message par erreur, veuillez le
mentionner imm�diatement � l'exp�diteur et effacer ce courriel."
_______________________________________________
ASN1 mailing list
[email protected]
http://lists.asn1.org/mailman/listinfo/asn1
