Programming in Lua Second Edition

329 Pages·2010·1.58 MB·English

Programming
ROBERTO IERUSALIMSCHY
in
Lua
2
nd
edition
Lua.org
Last update: Wed Jan 13 12:07:33 UTC 2010
Programming in Lua
Property of Ian Bloss <[email protected]>
Property of Ian Bloss <[email protected]>
Programming in Lua
Second Edition
Roberto Ierusalimschy
PUC-Rio, Brazil
Lua.org
Rio de Janeiro
Property of Ian Bloss <[email protected]>
Programming in Lua, Second Edition
byRobertoIerusalimschy
ISBN85-903798-2-5
Copyright(cid:13)c 2006,2003byRobertoIerusalimschy. Allrightsreserved.
[email protected].
BookcoverandillustrationsbyDimaquina. LualogodesignbyAlexandreNako.
TypesettingbytheauthorusingLATEX.
Although the author used his best efforts preparing this book, he assumes no
responsibility for errors or omissions, or for any damage that may result from
theuseoftheinformationpresentedhere. Allproductnamesmentionedinthis
bookaretrademarksoftheirrespectiveowners.
CIP(cid:150)BibliotecadoDepartamentodeInforma·tica,PUC-Rio
Ierusalimschy,Roberto
I22 ProgramminginLua/RobertoIerusalimschy. (cid:150)2nded.
(cid:150)RiodeJaneiro,2006.
xviii,308p. : 25cm.
Includesindex.
ISBN85-903798-2-5
1. Lua(Programminglanguage). I.Title.
005.133(cid:150)dc20
Property of Ian Bloss <[email protected]>
to Ida, Noemi, and Ana Lucia
Property of Ian Bloss <[email protected]>
Property of Ian Bloss <[email protected]>
Contents
Preface xiii
I The Language 1
1 GettingStarted 3
1.1 Chunks 4
1.2 SomeLexicalConventions 5
1.3 GlobalVariables 6
1.4 TheStand-AloneInterpreter 7
2 TypesandValues 9
2.1 Nil 10
2.2 Booleans 10
2.3 Numbers 10
2.4 Strings 11
2.5 Tables 13
2.6 Functions 17
2.7 UserdataandThreads 17
3 Expressions 19
3.1 ArithmeticOperators 19
3.2 RelationalOperators 20
3.3 LogicalOperators 21
3.4 Concatenation 22
3.5 Precedence 22
3.6 TableConstructors 22
vii
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viii Contents
4 Statements 27
4.1 Assignment 27
4.2 LocalVariablesandBlocks 28
4.3 ControlStructures 30
4.4 breakandreturn 34
5 Functions 35
5.1 MultipleResults 36
5.2 VariableNumberofArguments 39
5.3 NamedArguments 42
6 MoreAboutFunctions 45
6.1 Closures 47
6.2 Non-GlobalFunctions 50
6.3 ProperTailCalls 52
7 IteratorsandtheGenericfor 55
7.1 IteratorsandClosures 55
7.2 TheSemanticsoftheGenericfor 57
7.3 StatelessIterators 58
7.4 IteratorswithComplexState 60
7.5 TrueIterators 61
8 Compilation,Execution,andErrors 63
8.1 Compilation 63
8.2 CCode 67
8.3 Errors 67
8.4 ErrorHandlingandExceptions 69
8.5 ErrorMessagesandTracebacks 70
9 Coroutines 73
9.1 CoroutineBasics 73
9.2 PipesandFilters 76
9.3 CoroutinesasIterators 79
9.4 Non-PreemptiveMultithreading 81
10 CompleteExamples 87
10.1 DataDescription 87
10.2 MarkovChainAlgorithm 91
II Tables and Objects 95
11 DataStructures 97
11.1 Arrays 97
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ix
11.2 MatricesandMulti-DimensionalArrays 98
11.3 LinkedLists 100
11.4 QueuesandDoubleQueues 100
11.5 SetsandBags 101
11.6 StringBuffers 103
11.7 Graphs 104
12 DataFilesandPersistence 107
12.1 DataFiles 107
12.2 Serialization 109
13 MetatablesandMetamethods 117
13.1 ArithmeticMetamethods 118
13.2 RelationalMetamethods 120
13.3 Library-De(cid:2)nedMetamethods 122
13.4 Table-AccessMetamethods 122
14 TheEnvironment 129
14.1 GlobalVariableswithDynamicNames 129
14.2 Global-VariableDeclarations 131
14.3 Non-GlobalEnvironments 132
15 ModulesandPackages 137
15.1 TherequireFunction 138
15.2 TheBasicApproachforWritingModules 141
15.3 UsingEnvironments 143
15.4 ThemoduleFunction 144
15.5 SubmodulesandPackages 145
16 Object-OrientedProgramming 149
16.1 Classes 151
16.2 Inheritance 152
16.3 MultipleInheritance 154
16.4 Privacy 156
16.5 TheSingle-MethodApproach 158
17 WeakTables 161
17.1 MemoizeFunctions 163
17.2 ObjectAttributes 164
17.3 RevisitingTableswithDefaultValues 165
III The Standard Libraries 167
18 TheMathematicalLibrary 169
Property of Ian Bloss <[email protected]>