Programming Language Design Concepts

492 Pages·2004·1.901 MB·

by  Findlay, William, Watt, David Anthony

PROGRAMMING LANGUAGE
DESIGN CONCEPTS

PROGRAMMING LANGUAGE
DESIGN CONCEPTS
David A. Watt, University of Glasgow
with contributions by
William Findlay, University of Glasgow
Copyright2004 JohnWiley&SonsLtd,TheAtrium,SouthernGate,Chichester,
WestSussexPO198SQ,England
Telephone[phone]
Email(forordersandcustomerserviceenquiries):[email protected]
VisitourHomePageonwww.wileyeurope.comorwww.wiley.com
AllRightsReserved.Nopartofthispublicationmaybereproduced,storedinaretrievalsystemortransmittedin
anyformorbyanymeans,electronic,mechanical,photocopying,recording,scanningorotherwise,exceptunder
thetermsoftheCopyright,DesignsandPatentsAct1988orunderthetermsofalicenceissuedbytheCopyright
LicensingAgencyLtd,90TottenhamCourtRoad,LondonW1T4LP,UK,withoutthepermissioninwritingofthe
Publisher,withtheexceptionofanymaterialsuppliedspecificallyforthepurposeofbeingenteredandexecuted
onacomputersystemforexclusiveusebythepurchaseofthepublication.RequeststothePublishershouldbe
addressedtothePermissionsDepartment,JohnWiley&SonsLtd,TheAtrium,SouthernGate,Chichester,West
SussexPO198SQ,England,[email protected],orfaxedto([phone].
Thispublicationisdesignedtoprovideaccurateandauthoritativeinformationinregardtothesubjectmatter
covered.ItissoldontheunderstandingthatthePublisherisnotengagedinrenderingprofessionalservices.If
professionaladviceorotherexpertassistanceisrequired,theservicesofacompetentprofessionalshouldbesought.
ADAisaregisteredtrademarkoftheUSGovernmentAdaJointProgramOffice.
JAVAisaregisteredtrademarkofSunMicrosystemsInc.
OCCAMisaregisteredtrademarkoftheINMOSGroupofCompanies.
UNIXisaregisteredtrademarkofAT&TBellLaboratories.
OtherWileyEditorialOffices
JohnWiley&SonsInc.,111RiverStreet,Hoboken,NJ07030,USA
Jossey-Bass,989MarketStreet,SanFrancisco,CA94103-1741,USA
Wiley-VCHVerlagGmbH,Boschstr.12,D-69469Weinheim,Germany
JohnWiley&SonsAustraliaLtd,33ParkRoad,Milton,Queensland4064,Australia
JohnWiley&Sons(Asia)PteLtd,2ClementiLoop#02-01,JinXingDistripark,Singapore129809
JohnWiley&SonsCanadaLtd,22WorcesterRoad,Etobicoke,Ontario,CanadaM9W1L1
Wileyalsopublishesitsbooksinavarietyofelectronicformats.Somecontentthatappears
inprintmaynotbeavailableinelectronicbooks.
LibraryofCongressCataloging-in-PublicationData
Watt,DavidA.(DavidAnthony)
Programminglanguagedesignconcepts/DavidA.Watt;with
contributionsbyWilliamFindlay.
p.cm.
Includesbibliographicalreferencesandindex.
ISBN0-470-85320-4(pbk.:alk.paper)
1.Programminglanguages(Electroniccomputers)I.Findlay,William,
1947-II.Title.
QA76.7.W3882004
005.13–dc22
2003026236
BritishLibraryCataloguinginPublicationData
AcataloguerecordforthisbookisavailablefromtheBritishLibrary
ISBN0-470-85320-4
Typesetin10/12ptTimesTenbyLaserwordsPrivateLimited,Chennai,India
PrintedandboundinGreatBritainbyBiddlesLtd,King’sLynn
Thisbookisprintedonacid-freepaperresponsiblymanufacturedfromsustainableforestry
inwhichatleasttwotreesareplantedforeachoneusedforpaperproduction.
To Carol

Contents
Preface xv
Part I: Introduction 1
1 Programminglanguages 3
1.1 Programminglinguistics 3
1.1.1 Conceptsandparadigms 3
1.1.2 Syntax,semantics,andpragmatics 5
1.1.3 Languageprocessors 6
1.2 Historicaldevelopment 6
Summary 10
Furtherreading 10
Exercises 10
Part II: Basic Concepts 13
2 Valuesandtypes 15
2.1 Types 15
2.2 Primitivetypes 16
2.2.1 Built-inprimitivetypes 16
2.2.2 Definedprimitivetypes 18
2.2.3 Discreteprimitivetypes 19
2.3 Compositetypes 20
2.3.1 Cartesianproducts,structures,andrecords 21
2.3.2 Mappings,arrays,andfunctions 23
2.3.3 Disjointunions,discriminatedrecords,andobjects 27
2.4 Recursivetypes 33
2.4.1 Lists 33
2.4.2 Strings 35
2.4.3 Recursivetypesingeneral 36
2.5 Typesystems 37
2.5.1 Staticvsdynamictyping 38
2.5.2 Typeequivalence 40
2.5.3 TheTypeCompletenessPrinciple 42
2.6 Expressions 43
2.6.1 Literals 43
2.6.2 Constructions 44
2.6.3 Functioncalls 46
2.6.4 Conditionalexpressions 47
2.6.5 Iterativeexpressions 48
2.6.6 Constantandvariableaccesses 49
vii
viii Contents
2.7 Implementationnotes 49
2.7.1 Representationofprimitivetypes 49
2.7.2 RepresentationofCartesianproducts 50
2.7.3 Representationofarrays 50
2.7.4 Representationofdisjointunions 51
2.7.5 Representationofrecursivetypes 51
Summary 52
Furtherreading 52
Exercises 52
3 Variablesandstorage 57
3.1 Variablesandstorage 57
3.2 Simplevariables 58
3.3 Compositevariables 59
3.3.1 Totalvsselectiveupdate 60
3.3.2 Staticvsdynamicvsflexiblearrays 61
3.4 Copysemanticsvsreferencesemantics 63
3.5 Lifetime 66
3.5.1 Globalandlocalvariables 66
3.5.2 Heapvariables 68
3.5.3 Persistentvariables 71
3.6 Pointers 73
3.6.1 Pointersandrecursivetypes 74
3.6.2 Danglingpointers 75
3.7 Commands 77
3.7.1 Skips 77
3.7.2 Assignments 77
3.7.3 Properprocedurecalls 78
3.7.4 Sequentialcommands 79
3.7.5 Collateralcommands 79
3.7.6 Conditionalcommands 80
3.7.7 Iterativecommands 82
3.8 Expressionswithsideeffects 85
3.8.1 Commandexpressions 86
3.8.2 Expression-orientedlanguages 87
3.9 Implementationnotes 87
3.9.1 Storageforglobalandlocalvariables 88
3.9.2 Storageforheapvariables 89
3.9.3 Representationofdynamicandflexiblearrays 90
Summary 91
Furtherreading 91
Exercises 92
4 Bindingsandscope 95
4.1 Bindingsandenvironments 95
4.2 Scope 97
Contents ix
4.2.1 Blockstructure 97
4.2.2 Scopeandvisibility 99
4.2.3 Staticvsdynamicscoping 100
4.3 Declarations 102
4.3.1 Typedeclarations 102
4.3.2 Constantdeclarations 104
4.3.3 Variabledeclarations 104
4.3.4 Proceduredefinitions 105
4.3.5 Collateraldeclarations 105
4.3.6 Sequentialdeclarations 106
4.3.7 Recursivedeclarations 107
4.3.8 Scopesofdeclarations 108
4.4 Blocks 108
4.4.1 Blockcommands 109
4.4.2 Blockexpressions 110
4.4.3 TheQualificationPrinciple 110
Summary 111
Furtherreading 112
Exercises 112
5 Proceduralabstraction 115
5.1 Functionproceduresandproperprocedures 115
5.1.1 Functionprocedures 116
5.1.2 Properprocedures 118
5.1.3 TheAbstractionPrinciple 120
5.2 Parametersandarguments 122
5.2.1 Copyparametermechanisms 124
5.2.2 Referenceparametermechanisms 125
5.2.3 TheCorrespondencePrinciple 128
5.3 Implementationnotes 129
5.3.1 Implementationofprocedurecalls 130
5.3.2 Implementationofparametermechanisms 130
Summary 131
Furtherreading 131
Exercises 131
Part III: Advanced Concepts 133
6 Dataabstraction 135
6.1 Programunits,packages,andencapsulation 135
6.1.1 Packages 136
6.1.2 Encapsulation 137
6.2 Abstracttypes 140
6.3 Objectsandclasses 145
6.3.1 Classes 146
6.3.2 Subclassesandinheritance 151