Abstract syntax notation two
Timothy Ray Hines · 1996
Abstract Syntax Notation One is a formal notation for specifying data types and values for networking applications, e.g. client/server applications. Abstract Syntax Notation One was first used for specifying data types in Open Systems Interconnection service elements, e.g. Remote Operations Service Elements, and data types in Open Systems Interconnection protocols, e.g. Common Management Information Protocol. Compilers were soon written to convert Abstract Syntax Notation One source code into target programming languages, e.g. C or Pascal source code. The source code produced by an Abstract Syntax Notation One compiler was then integrated into a network application program. The original Abstract Syntax Notation One International standards included notation for defining macros. Abstract Syntax Notation One compiler writers found that writing Abstract Syntax Notation One compilers for macros was very difficult. The 1994 Abstract Syntax Notation One International standards moved macros to an appendix and replaced them by object-oriented constructs and techniques. Although the object-oriented constructs and techniques were included in Abstract Syntax Notation One, the writer(s) of the 1994 International standards did not include all constructs and techniques of the object-oriented paradigm. They did not include notation for defining class variables, instance variables, methods, superclasses and messages. This research examined the Abstract Syntax Notation One production rules and found that they were not usable by a compiler. Thus, an Abstract Syntax Notation LR(1) grammar was written from the Abstract Syntax Notation One production rules and used for an Abstract Syntax Notation One LR(1) compiler. Two new data types were added to the Abstract Syntax Notation One LR(1) grammar, OPERATION and MESSAGE, and changes were made to the existing CLASS data type to allow for class variables, instance variables, methods, superclasses and class keys. The new grammar is called Abstract Syntax Notation Two.