Higher-Order Perl: Transforming Programs with Programs

601 Pages·2005·8.56 MB·English

by  Mark Jason Dominus

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Praise forHigher-Order Perl . . .
Asaprogrammer,yourbookshelfisprobablyoverflowingwithbooksthatdidnothingtochangethewayyou
program...orthinkaboutprogramming.
You’regoingtoneedacompletelydifferentshelfforthisbook.
WhilediscussingcachingtechniquesinChapter3,MarkJasonDominuspointsouthowalargeenough
increaseinpowercanchangethefundamentalwayyouthinkaboutatechnology.Andthat’spreciselywhat
thisentirebookdoesforPerl.
ItraidsthedeepestvaultsandhighesttowersofComputerScience,andtransformsthemanyarcanetreasures
itfinds—recursion,iterators,filters,memoization,partitioning,numericalmethods,higher-orderfunctions,
currying,cutsorting,grammar-basedparsing,lazyevaluation,andconstraintprogramming—intopowerful
andpracticaltoolsforreal-worldprogrammingtasks:filesysteminteractions,HTMLprocessing,database
access,webspidering,typesetting,mailprocessing,homefinance,textoutlining,anddiagramgeneration.
Alongthewayitalsoscatterssmaller(butequallyinvaluable)gems,liketheelegantexplanationofthe
differencebetween“scope”and“duration”inChapter3,orthecarefulexplorationofhowbesttoreturn
errorflagsinChapter4.ItevenhaspracticaltipsforPerlevangelists.
Dominuspresentseventhemostcomplexideasinsimple,comprehensibleways,butnevercompromiseson
theprecisionandattentiontodetailforwhichheissowidelyandjustlyadmired.
Hiswritingis—asalways—lucid,eloquent,witty,andcompelling.
Aptlynamed,thistruly/is/aPerlbookofahigherorder,andessentialreadingforeveryseriousPerl
programmer.
—DamianConway,Co-designerofPerl6
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Mark Jason Dominus
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Preface........................................................... xv
  RecursionandCallbacks........................... 1
1.1 ...................................... 1
1.2 ...................................................... 3
1.2.1 WhyPrivateVariablesAreImportant.............................. 5
1.3 .............................................. 6
1.4 ............................................... 12
1.5 ...................... 16
1.6 -....................... 25
1.7 .......................................................... 26
1.7.1 MoreFlexibleSelection........................................ 32
1.8 ......................................... 33
1.8.1 FibonacciNumbers........................................... 33
1.8.2 Partitioning................................................ 35
  DispatchTables.................................... 41
2.1 ....................................... 41
2.1.1 Table-DrivenConfiguration .................................... 43
2.1.2 AdvantagesofDispatchTables................................... 45
2.1.3 DispatchTableStrategies....................................... 49
2.1.4 DefaultActions............................................. 52
2.2 ..................................................... 54
2.2.1 HTMLProcessingRevisited.................................... 59
  CachingandMemoization......................... 63
3.1 ........................................... 65
3.2 .................................................. 66
3.2.1 StaticVariables.............................................. 67
3.3 ..................................................... 68
3.4  ................................................... 69
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