This paper concerns the development of a family of higher level languages which are to serve as the target languages in the decompiling of assembler coded modules of small computer operating systems. The main objectiv...
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TRAIL is a block-structured language and programming system for the development of programming support systems and translators for problem-oriented languages on minicomputers. The programming system includes an interp...
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We postulate a general computing model and investigate the design and implementation of systems in the postulated environment. The model is drawn from our interpretation of the writings of John von Newmann 1 and other...
ISBN:
(纸本)9781450374903
We postulate a general computing model and investigate the design and implementation of systems in the postulated environment. The model is drawn from our interpretation of the writings of John von Newmann 1 and others. Its central concept is an abstraction of the capability of all digital computers to modify cells contents that represent addresses of other cells. We discuss three formulations of the model; namely, a “programminglanguage” formulation using vectors, pointers, and move operators, an “emulator” formulation extending the first formulation to include control structure and execution semantics, and a “mathematical” formulation. The proposed model is specifically intended for the interactive design and implementation of software (and also hardware) computer systems. The completeness and the hierarchial nature of the descriptions based on the model allow those descriptions to serve as simulation models and documentation for the complete system being described or for any well-defined part of the system.
The subject of data structures has received a great deal of attention in the past few years, especially in relation to computer-aided design. programming systems used for creating data structures (sometimes dignified ...
ISBN:
(纸本)9781450374866
The subject of data structures has received a great deal of attention in the past few years, especially in relation to computer-aided design. programming systems used for creating data structures (sometimes dignified by the name “graphical languages”)vary greatly in the rigidity of their representation and the types of facilities offered to the programmer. As an example of a high-level system, we can mention the formal language LEAP,1 in which the programmer can easily manipulate the logical elements of his model, and the structuring of the information (in the form of hash-coded tables) is performed automatically by the language system. At the other extreme we have a language like L62 which is a macro language useful in creating arbitrary list structures. The difference between these two “graphical languages” is so great that one could easily conceive of implementing the LEAP language using the L6 language. An excellent review of this subject is given by Gray.3The present work is a language in the latter mold, to be used in the implementation of data-structure systems, rather than being a data-structure system itself. In many respects L6 has served as a model of the type of facilities desired, although the final product owes its parentage to several languages.
Numerous papers and conference talks have recently been devoted to the affirmation or reaffirmation of various common-sense principles of computer program design and implementation, particularly with respect to operat...
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This paper presents an on-line, inter-active language system created specifically for scientists and engineers engaged in preparation, setup, control, and monitoring of hybrid computations. Through a special console o...
ISBN:
(纸本)9781450379151
This paper presents an on-line, inter-active language system created specifically for scientists and engineers engaged in preparation, setup, control, and monitoring of hybrid computations. Through a special console or a generalized input/output device, the user is afforded immediate access to both a computational process (software), and computation equipment (hardware). The language combines a complete algebraic interpreter with an expandable command and control repertoire. Through the latter, the language system may be made to perform a variety of special tasks, peculiar to the user, the equipment, or the *** language is designed specifically to facilitate implementation of an interpretive processor on a small digital computer in a hybrid configuration. This does not mean to imply, however, that the design is in any way limited to small computers. Rather, the intrinsic expandability of the language makes it possible to have a single communication medium that is upwards compatible across the whole spectrum of computer capability. The use of this programming system provides the hybrid computer analyst with great on-line flexibility coupled with a substantial reduction in the bothersome detail normally associated with digital computer programming.
This paper describes PAL—a new computer language. Given the fact that new languages seem to appear in computer literature at the rate of several per month, it seems incumbent on one who creates a new language to just...
ISBN:
(纸本)9781450374866
This paper describes PAL—a new computer language. Given the fact that new languages seem to appear in computer literature at the rate of several per month, it seems incumbent on one who creates a new language to justify having done so. In the present case, there are two important considerations: control and specification. Let us consider each of these in *** virtue of our having designed PAL, it is ours. There is no PAL Users Group or Committee of Vested Interests concerned with retaining upward compatibility with what was done last year (or last month). This doesn't mean we change the specifications of the language every few weeks (our students are, in a real sense, our Committee of Vested Interests), but it does mean we can make decisions on changes solely on technical grounds. More important, though, we can design the language to meet the criteria we think important. For example, the language almost demands interpretive execution. Since no one writes production programs in PAL we are able to put up with inefficiencies in the implementation that would otherwise be intolerable. Thus we have designed our own language so that we will have control over it.
THE AMBIT programminglanguage has been applied to problems in two areas. In the area of algebraic symbol manipulation, programs have been written in AMBIT for elementary arithmetic, elementary algebra, formal differe...
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THE AMBIT programminglanguage has been applied to problems in two areas. In the area of algebraic symbol manipulation, programs have been written in AMBIT for elementary arithmetic, elementary algebra, formal differentiation, set operations, and propositional calculus. In the area of list processing, a variety of programs have been written for syntactic analysis, including both "top-down" and "bottom-up" analysis. This programming effort was concurrent with the design of AMBIT and provided practical guidance for that design. It is believed that AMBIT is also appropriate for the programming of heuristic processes, such as formal integration, simplification of algebraic equations, and theorem proving. This paper is intended to exhibit the important features of AMBIT without entering into a complete and formal definition of AMBIT. The paper contains a brief informal definition of the language and several examples of programs written in the language. The informal definition discusses primarily those facilities of the language which are used in the example programs;other facilities currently available in AMBIT are not mentioned. The definition depends on the example programs for the illustration and clarification of difficult points, and the reader is advised to defer a detailed examination of the definition until he has read through the example programs. AMBIT has not yet been implemented for an automatic computer;however, a plan for an efficient implementation of AMBIT strongly influenced the design of the language. It is intended that an AMBIT program be compiled before execution and that operand data be converted from string form to linked-list form upon input to the computer. Rapid computer execution of AMBIT programs is made possible by the special role of parentheses and pointers in the operand data, and the speed of execution of an AMBIT program can approach that of a corresponding program written in machine or pseudo-machine language. This paper will not furthe
A tutoring system typically contains a domain expert, a student model, a pedagogical expert and the user interface. We will discuss the design and implementation of DSTutor, a tutoring system for denotational semantic...
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The general purpose mathematical programming systems have greatly changed in the last few years and the aim of such codes is no longer to give access to an efficient algorithm but to integrate the solution of linear p...
ISBN:
(纸本)9781450374866
The general purpose mathematical programming systems have greatly changed in the last few years and the aim of such codes is no longer to give access to an efficient algorithm but to integrate the solution of linear programming problems into a loop including the generation of the problem, its solution, its post optimal analysis and the edition of an output report of the results. The link between all these operations is done through a so-called control language *** these aspects are more or less the same from one code to another but we think that new approaches should be brought into their design, organization, and implementation. The development cost of such programs being very high, usually in the order of 15 to 30 man years, it is necessary to provide facilities in order to:- offer suitable users and programminglanguages;- have a modular design;- handle memory allocation in a semi-optimal way;- make modifications and extensions easier; and- facilitate day to day programmers tasks.I shall present, in the following pages, the objectives that we had in mind when we began to implement these facilities within the large scale mathematical programming system OPHELIE 2 which we developed for the CDC 6600.
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