摘要:

AbstractCode generators based on bottom‐up rewrite systems (BURS) are automatically generated from machine‐description grammars. They produce locally optimal code for expression trees, but their tables are large and require compile‐time interpretation. This paper describes a program that compiles BURS tables into a combination of hard code and data. Hard‐coding exposed important opportunities for compression that were previously hidden in the tables, so the hard‐coded code generators are not just faster but also significantly smaller than their predecessors. A VAX code generator takes 21.4Kbytes and identifies optimal assembly code in about 50 VAX instructions

ISSN:0038-0644    

DOI:10.1002/spe.4380210102

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractWe built a limited but successful user interface management system named HYPE which supports rapid interactive creation and organization of user interfaces for a large class of applications. HYPE is targeted at applications for which the user interface is only loosely coupled to the application. Examples of this class of application are ‘command line‐driven’ programs. Many applications in this class can be quickly given satisfactory direct‐manipulation interfaces with little or no reprogramming of the application. The programmer need only be familiar with HYPE, and not with the particular windowing system upon which it sits.1Theappearanceof the interface is specified interactively through the direct manipulation of interface components.2Thebehaviourof the interface is programmed with an interpreted procedural language which can send and receive messages and invoke system services. In particular, it can execute applications.3Thestructureof the interface is a tree of potentially‐visible objects which communicate with the user, the system, and each other through message passing. The tree structure facilitates grouping interfaces for related applications, or families of applications, into a single master interface.Visual layout, tree‐building, behaviour assignment (programming) and execution of the interface all occur within HYPE, a conjunction that makes it a powerful proto

ISSN:0038-0644    

DOI:10.1002/spe.4380210103

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractIn this paper, a new letter‐oriented perfect hashing scheme based on Ziegler's row displacement method is presented. A uniquen‐tuple from a given set of static letter‐oriented key words can be extracted by a heuristic algorithm. Then the extracted distinct n‐tuples are associated with a 0/1 sparse matrix. Using a sparse matrix compression technique, a perfect hashing function on the key words is then cons

ISSN:0038-0644    

DOI:10.1002/spe.4380210104

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractLANSF is a software package that was originally designed as a tool to investigate the behaviour of medium access control (MAC) level protocols. These protocols form an interesting class of distributed computations: timing of events is the key factor in them. The protocol definition language of LANSF is based on C, and protocols are specified (programmed) as collections of communicating, interrupt‐driven processes. These specifications are executable: an event‐driven emulator of MAC‐level communication phenomena forms the foundation of the implementation. Some tools for debugging, testing, and validation of protocol specifications are provided. We present key features of LANSF at the syntactic level, comment informally on the semantics of these features, and highlight some implementation issues. A complete example of a LANSF application is discussed in the App

ISSN:0038-0644    

DOI:10.1002/spe.4380210105

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractDistributed programming can be greatly simplified by language support for distributed communication, such as that provided by remote procedure call (RPC) or remote object invocation. This paper examines design and implementation issues in these systems, and focuses on the influence of the communication system on a distributed program. To make the discussion concrete, we introduce a single application as implemented in two environments: Modula‐2+, an extension of Modula‐2 with RPC, and Emerald, an object‐based language that supports remote object invocation. We show that small differences in the implementation of the communication system can have a significant impact on how distributed applications are struc

ISSN:0038-0644    

DOI:10.1002/spe.4380210106

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractEmerald is ageneral‐purposelanguage with aspects of traditional object‐oriented languages, such as Smalltalk, and abstract data type languages, such as Modula‐2 and Ada. It is strongly typed with a non‐traditional object model and type system that emphasize abstract types, allow separation of typing and implementation, and provide the flexibility of polymorphism and subtyping with compile‐time checking. This paper describes the Emerald language and its programming methodology. We give examples that demonstrate Emerald's features, and compare and contrast the Emerald approach to programming with the approaches used in other similar

ISSN:0038-0644    

DOI:10.1002/spe.4380210107

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380210101

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY