1987 4th Southern African Computer Symposiumhttps://hdl.handle.net/10500/244462024-03-29T06:33:09Z2024-03-29T06:33:09ZSet-oriented functional style of programmingMueller, CSMhttps://hdl.handle.net/10500/254432019-05-16T01:00:37Z1987-01-01T00:00:00ZSet-oriented functional style of programming
Mueller, CSM
Kritzinger, P.
A novel way of programming, which starts with specific details of a particular example
and abstracts these details into generalised sets, is proposed. The whole program is
constructed around the definition of these sets. Once the structure and type of the sets have been specified, the relationship between the sets is added to these set defintions. Thus, there is a move away from seeing the description of the data and relationships between the data as two separate parts, i.e. , the data definition and the body of the block. This paper concentrates on the method used to develop programs, using a tutorial approach to illustrate the ease of programming, debugging and modifiablity . An interesting aspect of the method is how a program can be developed by studying the details in the problem domain using a procedural approach and abstracting them into a final declarative definition.
1987-01-01T00:00:00ZExperience with a pattern-matching code generatorMulders, MASerwy, DAVan Biljon, WRhttps://hdl.handle.net/10500/254412019-05-16T01:00:34Z1987-01-01T00:00:00ZExperience with a pattern-matching code generator
Mulders, MA; Serwy, DA; Van Biljon, WR
Kritzinger, P.
An implementation of a Graham-Glanville type pattern-matching code generator for the NRIMS systems programming language SCRAP is discussed. The simple heuristic algorithm on which the pattern matcher is based is presented and compared to more exhaustive and complex algorithms implemented elsewhere. Finally, optimal instruction selection as a method of code improvement is discussed. The pattern matcher has been implemented for the Perkin Elmer 3200 and the Motorola 68000 instruction sets.
1987-01-01T00:00:00ZA data structure for exchanging geographical informationCooper, AKhttps://hdl.handle.net/10500/254212019-05-15T01:00:26Z1987-01-01T00:00:00ZA data structure for exchanging geographical information
Cooper, AK
Kritzinger, P.
Geographical information consists of non-spatial information (alphanumeric) and spatial information (vector and raster), the relationships between the non-spatial information and the spatial information, as well as the spatial relationships inherent in the spatial information, known as topology. It is undesirable for any exchange standard to lose, reduce or alter any information exchanged through the standard. For this reason, current alphanumeric and graphic exchange standards are insufficient for geographical information.
The project team drawing up a proposed South African standard for the exchange of geographical information has studied the proposals and standards of other countries and has held discussions with the users and potential users of computerized geographical information in this country. The project team fells that the best model for use with the data structures of the exchange standard is the relational one. This paper describes the nature of geographical information and the advantages of the relational model.
1987-01-01T00:00:00ZProtocol performance using image protocolsKritzinger, PShttps://hdl.handle.net/10500/254202019-05-15T01:00:25Z1987-01-01T00:00:00ZProtocol performance using image protocols
Kritzinger, PS
Kritzinger, P.
Performance analyses of data communication systems do not always rely
on a detailed analysis of the underlying protocols. Those analyses which do, usually
rely on an analysis of the protocol state transition graph. These graphs tend to become
very large for nontrivial protocols and the analyses correspondingly complex.
Image protocols are a recent approach to reduce the complexity of communication
protocol analysis. The method allows for the construction of an image protocol
which is generally sma.ller than the original protocol and its analysis therefore less
complex. An image protocol system is said to be faithful if it preserves the safety
and liveness properties \ of the original protocol system. In this paper we show
that an image protocol is also faithful as far as its performance is concerned, a result
which simplifies performance studies of the protocol considerably. An example
which illustrates the principles involved is included.
1987-01-01T00:00:00Z