Rationale for SQL Ada Module Description Language SAMeDL

G. Chastek
M. Graham
G. Zelesnik

Technical Report
CMU/SEI-91-TR-004

The SQL Ada Module Description Language, SAMeDL, is a language for the specification of Abstract Interfaces as delineated by the SQL Ada Module Extensions (SAME) methodology. The language is formally defined in the SAMeDL Reference Manual. This document is a companion to the Reference Manual. Whereas the Reference Manual is meant to be precise, the Rationale is meant to be clear.

An explanation of the problem solved by the SAMeDL is given. The creation of a new language is justified and the underlying principles of that language are described. Crucial issues in the language are then explained. These include:

The form and meaning of identifiers in the SAMeDL.
The role of and procedures for data definition in the SAMeDL. This includes support for enumerations and constants in the SAM- eDL.
The typing rules of the SAMeDL.

The proposed use of some SAMeDL features is also illustrated. These include Standard Post Processing and User Defined Base Domains.