计算机科学概论 课件chap 06

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1、Chapter6:ProgrammingLanguages6-1Chapter6:ProgrammingLanguages程序设计语言•6.1HistoricalPerspective•6.2TraditionalProgrammingConcepts•6.3ProceduralUnits•6.4LanguageImplementation•*6.5ObjectOrientedProgramming•*6.6ProgrammingConcurrentActivities•*6.7DeclarativeProg

2、ramming6-26.1HistoricalPerspective历史回顾•Machinelanguage-binaryformdirectcontrolsthehardware.机器语言•Assemblylanguage-mnemonicformofthemachinelanguage.汇编语言•High-levelprogramminglanguage-Englishlikelanguage.高级语言6-3Figure6.1Generationsofprogramminglanguages6-4Seco

3、nd-generation:Assemblylanguage•Assemblylanguage(汇编语言)-Amnemonicsystemforrepresentingmachineinstructions–Mnemonicnamesforop-codes–Identifiers:Descriptivenamesformemorylocations,chosenbytheprogrammer6-5AssemblyLanguageCharacteristics•One-to-onecorrespondenceb

4、etweenmachineinstructionsandassemblyinstructions–Programmermustthinklikethemachine•Inherentlymachine-dependent•Convertedtomachinelanguagebyaprogramcalledanassembler(汇编器、汇编程序)6-6ProgramExampleMachinelanguageAssemblylanguage156CLDR5,Price166DLDR6,ShippingChar

5、ge5056ADDIR0,R5R630CESTR0,TotalCostC000HLT6-7ThirdGenerationLanguage•Useshigh-levelprimitives–SimilartoourpseudocodeinChapter5•Machineindependent(mostly)•Examples:FORTRAN,COBOL•Eachprimitivecorrespondstoasequenceofmachinelanguageinstructions•Convertedtomach

6、inelanguagebyaprogramcalledacompiler(编译器)6-8ProgramExampleMachinelanguageAssemblylanguage156CLDR5,Price166DLDR6,ShippingCharge5056ADDIR0,R5R630CESTR0,TotalCostC000HLTClanguageTotalCost=Price+ShippingCharge;6-9Figure6.2Theevolutionofprogrammingparadigms程序设计范

7、型Functional函数式范型Objected-oriented面向对象范型Imperative命令型范型Declarative说明性范型6-10•TranslatorvsInterpreter–Translator(翻译器)/compiler(编译器)•aprogram,translatingprogramsexpressedinthesehigh-levelprimitivesintomachine-languageprograms–Interpreter(解释器)•Aprogram,similarto

8、translatorsexceptthattheyexecutetheinstructionsastheyaretranslatedinsteadofrecordingthetranslatedversionforfutureuse.6-116.2TraditionalProgrammingConcept•Aprogramconsistsofacollectionofstatements.•Stat