An optimizing compiler for the icon programming language

Compiling code for the Icon programming language presents several challenges, particularly in dealing with types and goal-directed expression evaluation. In order to produce optimized code, it is necessary for the compiler to know much more about operations than is necessary for the compilation of most programming languages. This paper describes the organization of the Icon compiler and the way it acquires and maintains information about operations. The Icon compiler generates C code, which makes it portable to a wide variety of platforms and also allows the use of existing C compilers for performing routine optimizations on the final code. A specially designed implementation language, which is a superset of C, is used for writing Icon's run-time system. This language allows the inclusion of information about the abstract semantics of Icon operations and their type-checking and conversion requirements. A translator converts code written in the run-time language to C code to provide an object library for linking with the code produced by the Icon compiler. The translation process also automatically produces a database that contains the information the Icon compiler needs to generate and optimize code. This approach allows easy extension of Icon's computational repertoire, alternate computational extensions, and cross compilation.     

Identification in a high-level graphics programming language

This paper describes programming elements for the identification in the high-level graphics programming language PASCAL/Graph [1]. The result is an extended form of the so-called indirect identification model. The identification process takes place in three steps: the user interaction, the search through the relevant graphical data, and the logical inquiry. By this method all reasonable identification actions can be formulated in a device-independent manner and also implemented efficiently. The concept can be carried over to other graphics programming languages easily.     

The high-level graphics programming language PASCAL/Graph

A high-level programming language like PASCAL offers data types, variables, constants and operators, with which the programmer can represent the actual world as a model inside the computer. The world of numbers and text has been represented in the computer for many years by various kinds of variables. The importance of computer graphics is increasing extremely fast. But the development of high-level programming languages, which include standard constructs for processing graphical informations, is far from where it could be. A good system should be based on understandable concepts, easy to learn and similar to normal programming, so that the programmer can fully concentrate upon the design of his pictures[1–4]. For these purposes PASCAL/Graph³ was designed and implemented[5–8].     

DGLa: A Distributed Graphics Language

A distributed graphics programming language called DGLa is presented,which facilitates the development of distributed graphics application.Facilities for distributed programming and graphics support are included in it,It not only supports synchronous and asynchronous communication but also provides programmer with multiple control mechanism for process communication.The graphics support of DGLa is powerful,for both sequential graphics library and parallel graphics library are provided.The design consideration and implementation experience are discussed in detail in this paper.Application examples are also given.     

基于Linux系统分析计算机C语言编程技巧

C语言程序设计是高效计算机专业学生必修的一门基础课程,同时也是后续课程的入门课程,对于掌握基本计算机技术有着重要意义。尤其在Linux系统下,该系统在所有操作系统中占着重要地位,如何掌握计算机C语言编程技巧是当务之急。为此,本文重点探讨基于Linux系统分析计算机C语言编程技巧。     

Experiences in database system implementation using a persistent programming language

The EXODUS database toolkit, and in particular the E persistent programming language, have been used in two substantial database system implementation efforts by the authors, the Ariel database rule system and the Triton nested relation DBMS. An important advantage of using a persistent programming language for database system implementation is that it is easy to implement special-purpose persistent objects used by the DBMS such as catalogs, rule indexes, and nested relational structures. Support for transactions built into a persistent programming language greatly reduces the effort required to implement a database system. A disadvantage observed is that it is not possible to map the type system of the DBMS to the type system of the underlying programming language while still retaining good performance for ad hoc queries. Also, software engineering difficulties arise when a persistent language makes a distinction between database types and main-memory types.     

Design of an arabic programming language (ARABLAN)

It was observed that school children in Arab countries find difficulty in learning programming in a language other than their native language. There are only few Arabic programming languages in the literature; most of which are never or partially implemented. In this paper, we present the design of a new Arabic programming language (ARABLAN) which is planned to be implemented for use in teaching programming for school children in Arab countries.     

Compiler to interpreter: experiences with a distributed programming language

One interpretive approach for handling concurrency is to provide an interpreter instance for each executing language‐level process. Such an approach has mainly been applied to concurrent implementations of logic and functional languages. This paper describes the use of this approach in constructing an interpreter for an imperative, distributed programming language from an existing compiler and run‐time support system (RTS). Primary design goals were to exploit the existing compiler to the extent possible as well as to have minimal impact on the RTS used to support concurrency. We have been successful in meeting these goals. Additionally, performance results show our interpreter's execution times compare favorably to the times required for compilation, linkage, and execution of small programs or programs with a significant number of calls to the RTS; on such programs, our interpreter's performance also compares favorably to that of the standard Java implementation. However, for larger programs and programs with fewer calls to the underlying RTS, the conventional compiler‐based implementation outperforms the interpreter implementation. For many distributed programs in which network costs dominate, the performances of the two implementations differ little. Copyright © 2001 John Wiley & Sons, Ltd.     

The systems programming language,Malus

This paper reports on the design and development of a high level language, Malus, for use in implementing a time-sharing system. Emphasized are the ways that the language and its compiler accommodate the specialized requirements of systems programming and programmers. Among these are the need to generate highly efficient object code, to allow inter-programmer communication by program self-documentation, and to define and organize system tables and data. In addition, the Malus compiler is highly modular; thus the language may be modified or augmented in response to user needs unforeseen during langauge design. Systems programs cannot be machine independent and Malus allows explicit control of emitted code when an application requires particular efficiency or use of privileged instructions. There is also a facility allowing nested redefinition of identifiers. Efficient storage management and data access is effected by the availability of based structures, a register storage class and built-in functions to facilitate their use. Malus is evaluated both in terms of some general criteria for systems implementation languages and by an appraisal of user reactions. While this assessment shows a few areas where the language might be improved, it is felt that Malus is a valuable and effective tool for systems implementation.     

The BLISS programming language: a history

The BLISS programming language was invented by William A. Wulf and others at Carnegie‐Mellon University in 1969, originally for the DEC PDP‐10. BLISS‐10 caught the interest of Ronald F. Brender of DEC (Digital Equipment Corporation). After several years of collaboration, including the creation of BLISS‐11 for the PDP‐11, BLISS was adopted as DEC's implementation language for use on its new line of VAX computers in 1975. DEC developed a completely new generation of BLISSs for the VAX, PDP‐10 and PDP‐11, which became widely used at DEC during the 1970s and 1980s. With the creation of the Alpha architecture in the early 1990s, BLISS was extended again, in both 32‐ and 64‐bit flavors. BLISS support for the Intel IA‐32 architecture was introduced in 1995 and IA‐64 support is now in progress. BLISS has a number of unusual characteristics: it is typeless, requires use of an explicit contents of operator (written as a period or ‘dot’), takes an algorithmic approach to data structure definition, has no goto , is an expression language, and has an unusually rich compile‐time language. This paper reviews the evolution and use of BLISS over its three decade lifetime. Emphasis is on how the language evolved to facilitate portable programming while retaining its initial highly machine‐specific character. Finally, the success of its characteristics are assessed. Copyright © 2002 John Wiley & Sons, Ltd.     

A language for high-level description of adaptive web systems

Adaptive Web systems (AWS) are Web-based systems that can adapt their features such as, presentation, content, and structure, based on users’ behaviour and preferences, device capabilities, and environment attributes. A framework was developed in our research group to provide the necessary components and protocols for the development of adaptive Web systems; however, there were several issues and shortcomings (e.g. low productivity, lack of verification mechanisms, etc.) in using the framework that inspired the development of a domain-specific language for the framework. This paper focuses on the proposal, design, and implementation of AWL, the Adaptive Web Language, which is used to develop adaptive Web systems within our framework. Not only does AWL address the existing issues in the framework, but it also offers mechanisms to increase software quality attributes, especially, reusability. An example application named PENS (a personalized e-News system) is explained and implemented in AWL. AWL has been designed based on the analysis of the adaptive Web domain, having taken into account the principles of reuse-based software engineering (product-lines), domain-specific languages, and aspect-oriented programming. Specially, a novel design decision, inspired by aspect-oriented programming paradigm, allows separate specification of presentation features in an application from its adaptation features. The AWL’s design decisions and their benefits are explained.     

C语言程序设计课程教学改革与实践

为提高C语言程序设计课程的教学质量,让学生更好地掌握核心技能,针对课程中教学难点多、语法知识多、学生重视程度不够等问题进行了认真分析,同时结合笔者在长期的教学实践过程中积累的经验,从教学目标、教学设计、教学内容选取、教学方法应用、考核方式等方面进行教学改革,提出了相关的解决方案,取得了较好的教学效果,教学质量明显提高。     

On the design of a special-purpose scientific programming language

Observations on the design of the special-purpose scientific programming language SL/1 are presented. SL/1 is intended for applications programming of the Control Data Corporation Cyber 203, a very high-performance vector processor, which is mainly used for scientific computation. The language design has been heavily influenced by the hardware characteristics of this machine and the needs of the Cyber 203 user community. Various aspects of the design of SL/1 are discussed and measurements of their use are presented. In addition, unexpected similarities between the resulting design of SL/1 and the design of FORTRAN are examined and several reasons for the continued widespread use of FORTRAN are suggested.     

Applications of Euclidean constructions to computer graphics

This paper presents an interactive graphics system called L.E.G.O. The purpose of L.E.G.O. is to model two- and three-dimensional objects using Euclidean geometry constructions. L.E.G.O. has a layered structure which makes it convenient to use, both for the experienced programmer and the novice. The programs may be written in a compiled language (C), written interactively in an interpreted language (LISP) or developed using a graphical interface in a multiple-window environment. Applications of L.E.G.O. include computer-assisted instruction of geometry and computer graphics, geometric modeling, and kinematic analysis. The use of imperative constructions and the powerful interface based on the idea of graphical programming are the most distinctive features of the system.     

Using the programming walkthrough to aid in programming language design

The programming walkthrough is a method for assessing how easy or hard it will be for users to write programs in a programming language. It is intended to enable language designers to identify problems early in design and to help them choose among alternative designs. We describe the method and present experience in applying it in four language design projects. Results indicate that the method is a useful supplement to existing design approaches.     

BCOOPL: Basic concurrent object‐oriented programming language

A small, object‐oriented language is introduced: BCOOPL (Basic Concurrent Object‐Oriented Programming Language). This language is specifically targeted to support component‐oriented programming. The main design goal of BCOOPL was to provide a small, but powerful set of language features that supports the construction of high‐quality components through well‐established software engineering practices, which include the separation of interfaces and implementations, weakly‐coupled objects, and abstraction. A number of design patterns based on these principles is actually built in the language. In particular, the observer, the mediator and the bridge are supported directly. This provides a strong foundation on which higher level component specification languages can be built. BCOOPL has a long research history. Its roots can be traced back to path expressions, and the concurrent object‐oriented programming languages Procol and Talktalk. As a result, BCOOPL only integrates essential language features that blend well and have proven their value in practice. Copyright © 2000 John Wiley & Sons, Ltd.     

The design and implementation of K: a high-level knowledge-base programming language of OSAM*.KBMS

The OSAM*.KBMS is a knowledge-base management system, or the so-called next-generation database management system, for non-traditional data/knowledge-intensive applications. In order to define, query, and manipulate a knowledge base, as well as to write codes to implement any application system, we have developed an object-oriented knowledge-base programming language called K to serve as the high-level interface of OSAM*.KBMS. This paper presents the design of K, its implementation, and its supporting KBMS developed at the Database Systems Research and Development Center of the University of Florida. Edited by Dennis McLeod. Received July 1992 / Accepted August 1995     

Adding multidimensionality to procedural programming languages

One of the most serious shortcomings of multidimensional languages is their inability to collaborate with conventional programming languages and systems. Multidimensional languages are used to define (potentially infinite) streams, grids, cubes, and so on, concepts which resemble in nature the familiar imperative arrays. The main difference is that the former entities are lazy while the latter are generally eager. This paper proposes the embedding of multidimensional languages into conventional ones as a form of definitional lazy arrays. The paper describes the details of an implementation of the proposed idea, as well as the expressibility and the performance of the resulting system. The main advantage of the new approach is that multidimensional languages can now benefit from the advanced features that have been developed for conventional languages. Moreover, multidimensionality adds to conventional languages the idea of lazy arrays, which in many cases offer significant advantages compared to the classical imperative arrays. Copyright © 1999 John Wiley & Sons, Ltd.     

HAGI, a High-level Application/Graphics Interface

HAGI is an object-oriented graphics system developed on top of the X window system. In addition to providing facilities that structured graphics systems such as GKS usually have, HAGI supports a high- level graphics paradigm with the following features:

• + In addition to graphical objects, the system provides a class of application objects with a higher level of abstraction than graphical objects.
• + Graphics manipulation operations can be issued simplyfrom application objects without explicitly referring to specific graphical objects. Thus graphics manipulation appears to be transparent to application programmers.
• + Graphical objects are designed to encompass more semantics, thus are at a level close to the application. For example, they useflexible visual objects to determine their visual appearance.

HAGI provides such a high-level application/graphics interface by maintaining a dependency relationship between graphical objects and application objects.