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This text contains description of the syntax and semantics of the language, MODEL, and techniques for its use. MODEL is a fifth-generation computer language. It is equational and non-procedural. (What these terms mean will be made clear to you as you begin to get involved in the MODEL system.) In this chapter, we shall discuss the value of the language. MODEL is a tool for systems and program design and development. Like most computer languages, the MODEL system comes with a compiler which is used to receive and analyze the language statements. But as we shall see later on, the whole process of analysis and coding is radically different in the MODEL system from programming methods in current practice.
Using today's conventional technology, it is necessary for the analyst to have knowledge of how a computer works internally. Otherwise, the analysis is often unusable by the programmers. To express data processing requirements that are translatable into a procedural language requires knowledge of how a computer executes the solution of the problem Non-procedural languages are problem-oriented and independent of knowledge of how the computer works.
MODEL eliminates the need for transfer of information from analyst to programmer. The MODEL system uses the computer to perform program design and coding automatically. In traditional systems design, after the requirements and analysis phases are completed, the programming task begins. Specifications are given to programmers who fmt perform the program &sign and then write and debug the programs. In MODEL, once a specification is completed, the "programming" task is also done as a byproduct The specification itself is entered into the computer; submitted to the MODEL compiler. A PL/I program is generated, as well as a series of reports about the newly generated program.
MODEL has facilities for automating all program development phases: design, coding and testing. It reduces the analyst's involvement with computer execution through having the compiler interface with the computer and its environment. The analyst writes a specification which is entered into the computer. The specification is transformed into a PL/I program by the MODEL compiler. As soon as the specification is completed the system is ready for testing. In short, MODEL is an outgrowth of a widespread need to make programming more natural and more accessible to non-programmers.
Welcome to the realm of non-procedurality. You are going to learn a new methodology for systems analysis. It will help you to complete complex projects and enable you to conceptualize problems in a clear, precise manner, without having to at the same time worry about its implementation in a computer.
Stanley M. Schwartz, "The Model Concept: Nonprocedural Programming for Nonprogrammers, II", . January 1986.
Date Posted: 28 January 2008