Programming_in Lua_2nd_Edition.pdf

PropertyoflanBloss ProgramminginLua Secondedition Robertolerusalimsch PUC-Rio.brazil ua.org Riodejaneiro PropertyoflanBloss ProgramminginLua.SecondEdition byRobertolerusalimschy ISBN85903798-2-5 Copyright2006,2003byRobertoIerusalimschy.Allrightsreserved. Theauthorcanbecontactedatrobertooluaorg BookcoverandillustrationsbyDimaquina.lualogodesignbyAlexandreNako TypesettingbytheauthorusingATEX Althoughtheauthorusedhisbesteffortspreparingthisbook,heassumesno responsibilityforerrorsoromissions,orforanydamagethatmayresultfrom theuseoftheinformationpresentedhere.Allproductnamesmentionedinthis bookaretrademarksoftheirrespectiveowners CIP-BibliotecadoDepartamentodeInformatica,PUC-Rio ferusalimschy,Roberto I22 ProgramminginLua/Robertolerusalimschy.-2nded Riodejaneiro.2006 xvi,308p.:25cm. Includesindex SBN85-9037982-5 1.Lua(Programminglanguage).I.Title 005.133-dc20 PropertyoflanBloss toIdanoemiandAnalucia PropertyoflanBloss PropertyoflanBloss Contents Prefacexiii TheLanguage 1GettingStarted3 1.1Chunks4 1.2SomeLexicalConventions5 1.3Globalvariables6 1.4TheStand-AloneInterpreter7 2Typesandvalues9 2.1Nil10 2.2Booleans10 2.3Numbers10 2.4Strings11 2.5Tables13 2.6Functions17 2.7UserdataandThreads17 3Expressions19 3.1ArithmeticOperators19 3.2RelationalOperators20 3.3LogicalOperators21 3.4Concatenation22 3.5Precedence22 3.6Tableconstructors22 PropertyoflanBloss Conte 4Statements27 4.1Assignment27 4.2Localvariablesandblocks28 4.3Controlstructures30 4.4breakandreturn34 5 unctions35 5.1MultipleResults36 5.2VariableNumberofArguments39 5.3NamedArguments42 6MoreAboutFunctions45 6.1Closures47 6.2Non-GlobalFunctions50 6.3ProperTailcalls52 7Iteratorsandthegenericfor55 7.1Iteratorsandclosures55 7.2TheSemanticsofthegenericfor57 7.3Statelessiterators58 7.4IteratorswithComplexState60 7.5TrueIterators61 8Compilation,Execution,andErrors63 8.1Compilation63 8.2CCode67 8.3Errors67 8.4ErrorHandlingandExceptions69 8.5ErrorMessagesandtracebacks70 9Coroutines73 9.1Coroutinebasics73 9.2Pipesandfilters76 9.3Coroutinesasiterators79 9.4Non-PreemptiveMultithreading81 10CompleteExamples87 10.1DataDescription87 10.2MarkovChainAlgorithm91 ITablesandobjects95 11Datastructures97 11.1Arrays97 PropertyoflanBloss 11.2Matricesandmulti-DimensionalArrays98 11.3LinkedLists100 11.4Queuesanddoublequeues100 11.5SetsandBags10 11.6StringBuffers103 11.7Graphs104 12DataFilesandPersistence107 12.1DataFiles107 12.2Serialization109 13Metatablesandmetamethods117 13.1ArithmeticMetamethods118 13.2RelationalMetamethods120 13.3Library-DefinedMetamethods122 13.4Table-Accessmetamethods122 14TheEnvironment129 14.1GlobalVariableswithDynamicNames129 14.2Global-VariableDeclarations131 14.3Non-GlobalEnvironments132 15Modulesandpackages137 15.1TherequireFunction138 15.2TheBasicapproachforWritingmodules141 15.3UsingEnvironments143 15.4ThemoduleFunction144 15.5Submodulesandpackages145 16object-OrientedProgramming149 16.1Classes151 16.2Inheritance152 16.3MultipleInheritance154 16.4Privacy156 16.5TheSingle-MethodApproach158 17WeakTables161 17.1MemoizeFunctions163 17.2ObjectAttributes164 17.3Revisitingtableswithdefaultvalues165 lThestandardlibraries167 18TheMathematicalLibrary169 PropertyoflanBloss