Target Programming Language Research Articles

A sequential real-time refinement calculus

We present a comprehensive refinement calculus for the development of sequential, real-time programs from real-time specifications. A specification may include not only execution time limits, but also requirements on the behaviour of outputs over the duration of the execution of the program. The approach allows refinement steps that separate timing constraints and functional requirements. New rules are provided for handling timing constraints, but the refinement of components implementing functional requirements is essentially the same as in the standard refinement calculus. The product of the refinement process is a program in the target programming language extended with timing deadline directives. The extended language is a machine-independent, real-time programming language. To provide valid machine code for a particular model of machine, the machine code produced by a compiler must be analysed to guarantee that it meets the specified timing deadlines.

Program design languages: How much detail should they include?

This experiment evaluated the effectiveness of using a program design language (PDL) specifically designed to aid in coding a corresponding programming language. PDLs were designed to reflect the constructs and level of detail of three particular programming languages (i.e. MACRO-11, FORTRAN and APL). We measured the performance of programmers coding from these various PDLs in MACRO-11 and FORTRAN. Each participant was presented with three programs in one of the two programming languages. Several lines had been deleted from each program. A participant's task, performed online, was to complete the code using the PDLs. For programmers coding in MACRO-11, the MACRO-like PDL was associated with the shortest coding times. Further, the participants said they found the MACRO-like PDL easiest to use, and they relied on it most heavily. For programmers coding in FORTRAN, the FORTRAN-like PDL was associated with the shortest coding times; the participants said they found the FORTRAN-like PDL easiest to use, and they relied on it most heavily. From these data we conclude that optimal use of a PDL requires that it be tailored to the target programming language in terms of type of construct and level of detail.

The challenges of teaching computer programming

The challenges of teaching computer programming

An example of stepwise refinement of distributed programs: quiescence detection

We propose a methodology for the development of concurrent programs and apply it to an important class of problems: quiescence detection. The methodology is based on a novel view of programs. A key feature of the methodology is the separation of concerns between the core problem to be solved and details of the forms of concurrency employed in the target architecture and programming language. We begin development of concurrent programs by ignoring issues dealing with concurrency and introduce such concerns in manageable doses. The class of problems solved includes termination and deadlock detection.