计算机专业英语(霍洪涛)课件Chapter 5

1、Chapter 5 Programming LanguageReviewv终端v领域v内核模式v如鲠在喉v杰出的v诉讼v常规的v占主导的v成见v专利税2terminalprovince，territorykernel modelawsuitconventionalstereotypeprominent, remarkable, extraordinarya lump in the throatroyaltypredominantReviewvThe Structure of A Computer System 3at the bottom the lowest layer next comes

2、In machine language layeron the top finally A major function of ReviewvLayered Systems Layer 0 dealt with(p71P2L1) 0层处理进程的分配，在干扰发生或者计时器终止时在进程件转换。 Layer 1 did (p71P3L1) 1层是内存管理。 Layer 2 handled (p71P3L1) 2层控制各进程和操作平台之间的通信。 Layer 3 took care of (p71P2L2) 3层管理输入/输出设备以及进出的信息流缓冲。 Layer 4 was where (p72L1

3、) 4层放置的是用户程序。 was located in layer 5 (p71L3).系统操作进程放在5层。 4Unit 1 History of Programming Languagev1. Prehistory Herman Hollerith realized that he could encode information on punch cards when he observed that railroad train conductors would encode the appearance of the ticket holders on the train tick

4、ets using the position of punched holes on the tickets(p94L2). 在看见检票员把乘客的外形通过穿孔的位置编码在票上的时候，Hollerith意识到他可以把信息编码在穿孔卡片上。5Unit 1 History of Programming Languagev1. Prehistory The Turing machine was an abstraction of the operation of a tape-marking machine, for example, in use at the telephone companies

5、(p94P2L4). 图灵机是一台磁带标记机器的操作的抽象，例如，用在电讯公司。6Unit 1 History of Programming Languagev albeit(p94RL4) conj. 虽然；即使 introduce a fact or comment that reduces the force or significance of what you have just said. 例： Charless letter was indeed published, albeit in a somewhat abbreviated form. 查尔斯的信确实被刊登了出来，尽管有

6、些删节。v though conj.虽然 introduce a statement in a subordinate clause which contrasts with the statement in the main clause. 例： Everything I told them was correct, though I forgot a few things. 我告诉他们的全部正确，尽管我忘了几件事。7Unit 1 History of Programming Languagev2. The 1940s The limited speed and memory capacit

7、y forced programmers to write hand tuned assembly language programs(p94RL3). 有限的速度和内存容量迫使程序员手工编写优化 的汇编程序。 force v.强迫，迫使 drive into 例句：The recession and hospital bills drove them into bankruptcy. 经济萧条和医院的账单逼得他们破产了。8Unit 1 History of Programming Languagev3. The 1950s and 1960s-two key innovationsA.The

8、 use of Backus-Naur Form(BNF) for describing the languages syntax. Nearly all subsequent programming languages have used a variant of BNF to describe the context-free portion of their syntax(p95Pr3P2). 使用巴科斯范式来描述语言的句法。几乎所有后来的编程语言都使用了巴科斯范式的变体来描述语法中与上下文无关的那部分。vsyntax n.句法，语法vsubsequent adj. 后来的，随后的vva

9、riant n.变体，变化9varied adj.各种各样的variable n.变量Unit 1 History of Programming Languagev portion n.部分A portion of something is a part of it. 例：Damage was confined to a small portion of the castle. 城堡仅有一小部分受到了损坏。v proportion n.部分A proportion of a group or an amount is a part of it. 例： A large proportion of

10、 the dolphins in that area will eventually die. 那个地区的很大一部分海豚最终会死。v part n.部分A part of something is one of the pieces, sections, or elements that it consists of. 例： I like that part of Cape Town. 我喜欢开普敦的那个地方。10Unit 1 History of Programming Languagev3. The 1950s and 1960s-two key innovationsB. The int

11、roduction of lexical scoping for names in arbitrarily nested scopes(p95Pr3P2). 为任意嵌套作用域的命名引进了词法域vlexical adj.词法的varbitrary adj.数任意的；武断的 arbitrary value 任意值vnest v.筑巢；计嵌套vscope n.范围；计作用域11Unit 1 History of Programming Languagev4. 1967-1978: Establishing Fundamental Paradigms Although the debate raged

12、 hotly at the time, nearly all programmers now agree that, even in languages that provide GOTO, it is bad style to use it except in rare circumstances(p96P3L4). 尽管当时的辩论很激烈，现在几乎所有的程序员都同意，就算是在提供了GOTO的语言，使用GOTO也是不好的编程风格，也只有在极少的情况下才会使用。paradigm n.范例rage vi. 流行，风行；大怒，发怒rare adj.稀有的，罕见的12Unit 1 History of

13、 Programming Languagevmerit(p96L4) 好处n. its advantages or other good points. 例： They have been persuaded of the merits of peace. 他们已经被说服，认识到了和平的好处。vadvantage 优势n. a way in which one thing is better than another. 例： The great advantage of home-grown oranges is their magnificent flavour. 自产橙子的巨大优势是其极好

14、的味道。13Unit 1 History of Programming Languagev5. The 1980s: Consolidation, Modules, Performance(p96Pr5)1.The 1980s were years of relative consolidation. 20世纪80年代相对整合的一段时期2. One important new trend in language design was an increased focus on programming for large-scale systems through the use of modu

15、les, or large-scale organizational units of code. 语言设计的一个重要的新趋势是应用模块或者大型企业级代码来开发大规模系统已经成为关注的焦点。14Unit 1 History of Programming Languagev5. The 1980s: Consolidation, Modules, Performance(p96Pr5)3. The 1980s also brought advances in programming language implementation. 20世纪80年代也带来了程序语言实施方面的发展。15Unit 1

16、 History of Programming Languagev6. The 1990s: the Internet Age In particular, the Java programming language rose to popularity because of its early integration with the Netscape Navigator web browser, and various scripting languages achieved widespread use in developing customized applications for

17、web servers(p97L3). 特别是，Java编程语言因为早期和网景领航员浏览器的集成流行起来。另外，多种多样的脚本语言在为网络服务器开发定制化应用时得到广泛应用。16Unit 1 History of Programming LanguagevKey wordvpredate(p94L1)vintellectual(p94RL1)visolate(p95L3)vmilestone(p95Pr3P2L1)vinfluential(p95Pr3P3L1)vdescendant(p96L2)vancestry(p96L3)vbewildering(p96P3RL1)17v.(日期上日期上

18、)早于早于; 先于先于adj.智力的智力的v. 隔离；孤立隔离；孤立n.里程碑里程碑adj.有影响力的有影响力的n. 后裔；子孙后裔；子孙n. 祖先祖先adj.令人疑惑的令人疑惑的Unit 2 Object-oriented Programmingv Definition(What is OOP?): Object-oriented programming (OOP) is a programming paradigm that uses “objects” to design applications and computer programs(p99L1). 面向对象编程是使用“对象”来设

19、计应用和计算机游戏的一种编程范例。v Function(What problems and how the problems are addressed?)： Object-oriented programming in part addresses the problem of maintaining software quality by strongly emphasizing modularity in software(p99P2RL2). 面向对象编程通过强烈地强调软件里的模块部分解决了保证软件质量的问题。18Unit 2 Object-oriented ProgrammingvD

20、ifferences with traditional views： Object-oriented programming may be seen as a collection of cooperating objects as opposed to a traditional view in which a program may be seen as a collection of functions, or simply as a list of instructions to the computer(p99P3L1). 面向对象的程序可以看做是一个由相互合作的对象组成的集合，而传

21、统的看法则被程序看成有许多函数组成的集合，或者简单的计算机指令集合。19Unit 2 Object-oriented Programmingvcapable(p99P3L3) adj. If a person or thing is capable of doing something, they have the ability to do it. 有能力的 He appeared hardly capable of conducting a coherent conversation. 他看起来几乎没有能力进行连贯的谈话vcompetent adj. Someone who is comp

22、etent is efficient and effective. 有能力的 例： He was a loyal and very competent civil servant. 他是一个忠诚、很有能力的公务员。20Unit 2 Object-oriented Programmingv1. Fundamental conceptsv1.1 Class A class should typically be recognizable to a non-programmer familiar with the problem domain, meaning that the characteri

23、stics of the class should make sense in context. Collectively, the properties and methods defined by a class are called members(p99RL4). 类对于熟悉问题域的非程序员来说通常应当是可识别的，也就是说，类的特征在上下文中应该是有意义的。共同地，由类决定的属性和动作被称为成员。21Unit 2 Object-oriented Programmingv1. Fundamental conceptsv1.2 Object An object is a particula

24、r instance of a class. The set of values of the attributes of a particular object is called its state(p100Pr1.2). 一个对象就是类的一个特定的实例。一个特定对象的一组属性值称为它的状态。v1.3 Method A method is an objects abilities(p100Pr1.3). 一个方法就是一个对象的能力。22Unit 2 Object-oriented Programmingv1. Fundamental conceptsv1.4 Inheritance Sub

25、classes inherit attributes and behaviors from their parent classes, and can introduce their own. When an object or class inherits its traits from more than one ancestor class, and neither of these ancestors is an ancestor of the other, then its called multiple inheritance(p100Pr1.4L3). 子类从它们的父类继承了属性

26、和动作，并且可以引入它们自己的(属性和动作)。当一个对象或者类从不止一个祖先类继承特点，并且这些祖先类相互并不是另一个的祖先，那么这就叫做多重继承。23Unit 2 Object-oriented Programmingv1. Fundamental conceptsv1.5 Encapsulation Conceals the exact details of how a particular class works from objects that use its code or send massages to it(p100RL4). (封装)向对象隐藏了一个特定类如何运作的具体细节

27、。对象只是使用类的编码或者发消息给类。24Unit 2 Object-oriented Programmingv1. Fundamental conceptsv1.6 Abstraction Simplifying complex reality by modeling classes appropriate to the problem, and working at the most appropriate level of inheritance for a given aspect of the problem(p101Pr1.6L1). 通过塑造对问题合适的类来简化复杂的现实，并且对

28、于特定方面的问题选择在最合适的继承层工作。25Unit 2 Object-oriented Programmingv1. Fundamental conceptsv1.7 Polymorphism Polymorphism is behavior that varies depending on the class in which the behavior is invoked, that is, two or more classes can react differently to the same message(p101Pr1.7L1). 多态性是根据在不同类被调用而产生不同的行为，也就是，多个类可以对同样的信息有不同的反应。26Unit 2 Object-oriented Programmingv2. History Introduceobject IntroduceOOP Develop Increasingly popularvIntroduceobject Objects as programming entities were introduced in the 1960s in Simula 67(p101RP1L1). 对象作为编程实体在20世纪60年代引入Sim