scope:

Scope and objective

This Recommendation defines the data and action language features of the Specification and Description Language. The features defined in this document include: encoding and decoding of data communicated over channels, the definition of data types (including interfaces), the definition of variables (including parameters), the definition and application of operations, the evaluation of expressions and assignment of values to variables. Without these features the language would be of limited use. For this reason, even very simple specifications in the Specification and Description Language use ITU-T Z.104 features. Together with [ITU-T Z.100], [ITU-T Z.101], [ITU-T Z.102], [ITU-T Z.103], [ITU-T Z.105], [ITU-T Z.106] and [ITU-T Z.107], this Recommendation forms a reference manual for the language.

Objective

The objective of this Recommendation is to fully define the data related features of the Specification and Description Language (except [ITU-T Z.105] and [ITU-T Z.107] features). Some of the ITU-T Z.104 material is also in [ITU-T Z.100] and [ITU-T Z.101]. These definitions should be entirely consistent. The difference between the descriptions in [ITU-T Z.100] and [ITU-T Z.101] and the definition in Recommendation ITU-T Z.104 is that the former descriptions are overviews to enable data to be used with other features of SDL-2010, whereas the ITU-T Z.104 definition is intended to be complete (with the exception of definition of data types in ASN.1 modules and object-oriented - see [ITU-T Z.105] and [ITU-T Z.107] respectively).

Recommendation ITU-T Z.104 also includes a mechanism for binding data definitions and actions expressed in the concrete syntax from other notations as described in Annex C to the abstract grammar and semantics of SDL-2010 and data binding in clause 7.2. By default, the concrete grammar is as given in the main body of ITU-T Z.104 or [ITU-T Z.101], [ITU-T Z.102], [ITU-T Z.103], [ITU-T Z.105], [ITU-T Z.106] and [ITU-T Z.107].

Application

This Recommendation is part of the reference manual for the Specification and Description Language.

The use of data is so fundamental, that even the simplest specifications need some data language features. Therefore, it is almost certain that some features defined in Recommendation ITU-T Z.104 will appear in any specification in SDL-2010.