Steen Oluf Karlsen wrote: > > Its an identifier just like callStart and callEnd. > > I've spent many a day wondering about these. > > In a programming language you have builtin types. > Then you define your own types. Then you declare > variables - each must be declared as some previously > defined type whether builtin or user defined. > > However in ASN.1 you have components. These are more > like members of big structures (C structs) - often > the whole spec sums up to one big struct - though > most often a kind of "union" of many types. > > The use of variables is rare in protocol specs as I have > come across them. They have this odd name "value" in > ASN.1 (correct me if this was changed).
In ASN.1 you can define "value references". A value reference is a name that designates a particular abstract value. A value reference is not a variable. It is more similar to a constant in programming languages (a name bound to a value that cannot be changed). Alessandro Triglia > > To me a variable can take one of a set of values - this > actually constitites the actual type of the variable. > > All written from the top of my head ! Pls correct if > outdated or wrong ! > > Steen Oluf Karlsen > Soholtvej 6 > Vester Vandet > DK-7700 Thisted > Danmark > Tel +45 97 97 72 72 > email [EMAIL PROTECTED] > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf > Of [EMAIL PROTECTED] > Sent: 19. december 2003 07:33 > To: [EMAIL PROTECTED] > Subject: [ASN.1] When Sequence > > > Hi All, > I am very new to this mailing list and also to ASN.1 > syntax. I just come across "when SEQUENCE" syntax in one of > the message type of RASV4. Following is a syntax of that message - > > CapacityReportingSpecification ::= SEQUENCE > { > when SEQUENCE > { > callStart NULL OPTIONAL, > callEnd NULL OPTIONAL, > ... > }, > ... > } > > > I was just wondering about what is the significance of > "when" as a prefix to SEQUENCE ? Can anybody tell me about this. > > Thanks in advance > Upma > > > > > >
