Steps in Scala: An Introduction to Object-Functional Programming

Cover......Page 1
Half-title......Page 3
Title......Page 5
Copyright......Page 6
Dedication......Page 7
Contents......Page 9
Preface......Page 15
1.1 Object orientation......Page 21
1.2 An overview of functional programming......Page 27
1.3 Extendable languages......Page 29
1.4 Scala: beyond the Java programming language......Page 34
2.1 “HelloWorld!” in Scala......Page 36
2.2 Scala’s basic types......Page 38
2.3 Classes and objects......Page 44
2.4 Some basic operators......Page 49
2.5 Basic built-in control structures......Page 52
2.6 Subclasses and inheritance......Page 58
2.7 Functions......Page 62
2.8 Arrays and tuples......Page 68
2.9 Command line arguments......Page 73
2.10 Sets......Page 76
2.11 Hash tables......Page 79
2.12 Memo functions......Page 82
2.13 Lists......Page 84
2.14 Strings......Page 94
2.15 Regular expressions......Page 96
2.16 Scientific computation with Scala......Page 104
2.17 Inner classes......Page 107
2.18 Packages......Page 108
2.19 Documentation comments......Page 110
2.20 Annotations......Page 112
3.1 Playing with trees......Page 115
3.2.1 Types of patterns......Page 123
3.2.2 Sealed classes......Page 127
3.2.3 Optional values......Page 128
3.3 Traits and mix-in composition......Page 129
3.4 Sorting objects......Page 136
3.5 More on functions......Page 138
3.6.1 Types of polymorphism......Page 145
3.6.2 Overloading......Page 147
3.6.3 Implicit conversion: a form of coercion......Page 148
3.6.4 Parametric polymorphism......Page 151
3.6.5 More on implicit parameters......Page 156
3.6.6 Inclusion polymorphism......Page 157
3.6.7 Covariance, contravariance and invariance......Page 158
3.6.8 Bounded polymorphism......Page 160
3.6.9 Views and view bounds......Page 163
3.6.10 Existential types......Page 164
3.6.12 Type erasure......Page 167
3.7 Nominal and structural typing......Page 168
3.8∗ Higher order polymorphism......Page 170
3.9 Streams are “infinite” lists!......Page 176
3.10∗ More on memo functions......Page 178
3.11 Assertions......Page 179
3.12 Setters and getters......Page 181
3.13∗ Monads......Page 183
4.1 Language parsers......Page 191
4.2 Scala’s parser builders......Page 194
4.3 An interpreter for a toy language......Page 197
4.4 Domain-specific languages......Page 204
4.5 Monadic parsing......Page 205
5.1 What is XML?......Page 207
5.2 Basic XML content manipulation......Page 209
5.3 Producing XHTML content with Scala......Page 213
5.4 XML input and output......Page 216
5.5 XML searching à la Scala......Page 217
5.6 XML pattern matching......Page 219
6.1 “HelloWorld!” again!......Page 222
6.2 Interactive GUI programming......Page 227
6.3 Building a desktop calculator......Page 232
6.4 Simple graphics with Scala......Page 236
6.5 Creating pictorial data......Page 245
6.6 Dialogs......Page 251
6.7.1 Radio buttons......Page 258
6.7.2 Check boxes......Page 260
6.7.3 Combo boxes......Page 263
6.7.4 Building a text editor with a menu bar and menus......Page 270
6.8.1 Simple tabs......Page 277
6.8.2 User-disposable tabs......Page 278
6.8.3 GUI lists, sliders, and split panes......Page 283
6.9 More on text components......Page 286
6.10 Tables......Page 291
6.11 Applets......Page 295
6.12 Functional graphics......Page 300
7.1 Programming with threads: an overview......Page 303
7.2 Animation with threads......Page 309
7.3 Using mailboxes......Page 313
7.4 Actors: basic ideas......Page 315
7.5 Message passing with actors......Page 318
7.6 Computing factorials with actors......Page 323
8 On paths and a bit of algebraic abstraction......Page 327
8.1 Path requirements......Page 328
8.2 Path API......Page 330
8.3 Empty paths......Page 331
8.4 Unix paths......Page 332
8.5 Windows paths......Page 334
8.5.3 Drive absolute paths......Page 335
8.6 Path factory......Page 338
8.6.1 A few more utility methods......Page 340
8.6.2 The factory method......Page 342
8.6.3 Canonical paths......Page 344
8.7 Notes on representation......Page 346
8.9 Testing paths......Page 347
8.9.1 User-friendliness......Page 348
8.10 Algebraic abstractions......Page 349
8.10.1 Semigroups......Page 350
8.10.2 Monoids......Page 351
9 Virtual files coming into existence......Page 354
9.1.2 Design goals......Page 355
9.1.3 VFS API......Page 356
9.1.4 VFile API......Page 359
9.2 Native file system......Page 362
9.3 Memory file system......Page 366
9.3.1 Memory VFS......Page 367
9.3.2 Memory files and folders......Page 368
9.4.1 Preliminaries......Page 371
9.4.2 Zip VFS......Page 374
9.4.4 A VFile that does not exist......Page 377
9.4.5 Zip VFile......Page 378
10.1 Matching files......Page 380
10.2 A less procedural approach......Page 382
10.3 Glob-style matching implementation......Page 387
10.3.1 Remarks on a (non) pure-Scala implementation......Page 390
10.4 Using glob-style matching......Page 391
10.5 Going boolean......Page 396
10.5.1 Less redundancy......Page 397
10.6 Any level down the hierarchy......Page 399
11.1.1 Iterables......Page 400
11.1.2 Traversables......Page 401
11.1.3 Test trees and expected search results......Page 402
Depth-first search......Page 403
11.2.1 The shape of our data......Page 405
Subtle type inferring issues......Page 407
Can we do better than wrapping?......Page 408
Children provisioning......Page 409
Iteration from the inside......Page 410
11.3 Traversing the hierarchy......Page 417
User-directed versus collection-directed......Page 419
Object-oriented or functional......Page 420
Interchangeability between approaches......Page 421
12.1 Introduction......Page 422
Data-centric decomposition......Page 423
Operation-centric decomposition......Page 424
12.3 Data-centric approach with subclassing......Page 427
Automatic instance transformations......Page 428
On the constructor of ReprPlusD......Page 429
12.4 Operation-centric approach with subclassing......Page 430
12.5 Generic operation-centric approach......Page 432
12.6 Generic data-centric approach......Page 435
12.7 OO decomposition with abstract types......Page 437
Adding new data......Page 438
Adding new operations......Page 439
12.8 Operation-centric decomposition with abstract types......Page 441
Adding new operations......Page 443
12.9 Summary......Page 444
13.1 Mechanical symbol manipulation......Page 446
13.2 The grammar......Page 447
13.3 Basic data model......Page 448
13.4 Experimenting with the data model......Page 449
13.5.1 Finding the derivative of a function......Page 450
13.5.2 Simplifying an expression......Page 452
13.5.3 Pretty-printing expressions......Page 453
13.6 Putting it all together......Page 456
13.8 Summary and further reading......Page 457
Appendix A: Multimedia processing......Page 459
B.1 Introduction......Page 461
B.3 Requirement and candidate application......Page 462
B.4 Proguard configuration......Page 465
B.5 Trading space for time......Page 467
Version of scalac......Page 469
Debugging Info......Page 470
Verbosity......Page 471
Class paths......Page 472
Explain type errors......Page 473
Advanced options related to compiler phases......Page 474
Other advanced options......Page 479
The private/experimental -Y options......Page 480
C.2 The Scala interpreter......Page 482
D.1 Lexical entities......Page 483
D.2 The rest of the language......Page 484
References......Page 490
Name index......Page 494
Subject index......Page 495