Foreword xvii
Preface xix
About the Author xxi
Chapter 1: The Basics 1
1.1 The Scala Interpreter 1
1.2 Declaring Values and Variables 3
1.3 Commonly Used Types 4
1.4 Arithmetic and Operator Overloading 5
1.5 Calling Functions and Methods 7
1.6 The apply Method 8
1.7 Scaladoc 8
Exercises 11
Chapter 2: Control Structures and Functions 13
2.1 Conditional Expressions 14
2.2 Statement Termination 15
2.3 Block Expressions and Assignments 16
2.4 Input and Output 17
2.5 Loops 18
2.6 Advanced for Loops and for Comprehensions 19
2.7 Functions 20
2.8 Default and Named Arguments 21
2.9 Variable Arguments 22
2.10 Procedures 23
2.11 Lazy Values 23
2.12 Exceptions 24
Exercises 26
Chapter 3: Working with Arrays 29
3.1 Fixed-Length Arrays 29
3.2 Variable-Length Arrays: Array Buffers 30
3.3 Traversing Arrays and Array Buffers 31
3.4 Transforming Arrays 32
3.5 Common Algorithms 34
3.6 Deciphering Scaladoc 35
3.7 Multidimensional Arrays 37
3.8 Interoperating with Java 37
Exercises 38
Chapter 4: Maps and Tuples 41
4.1 Constructing a Map 41
4.2 Accessing Map Values 42
4.3 Updating Map Values 43
4.4 Iterating over Maps 43
4.5 Sorted Maps 44
4.6 Interoperating with Java 44
4.7 Tuples 45
4.8 Zipping 46
Exercises 46
Chapter 5: Classes 49
5.1 Simple Classes and Parameterless Methods 49
5.2 Properties with Getters and Setters 50
5.3 Properties with Only Getters 53
5.4 Object-Private Fields 54
5.5 Bean Properties 55
5.6 Auxiliary Constructors 56
5.7 The Primary Constructor 57
5.8 Nested Classes 60
Exercises 63
Chapter 6: Objects 65
6.1 Singletons 65
6.2 Companion Objects 66
6.3 Objects Extending a Class or Trait 67
6.4 The apply Method 67
6.5 Application Objects 68
6.6 Enumerations 69
Exercises 71
Chapter 7: Packages and Imports 73
7.1 Packages 74
7.2 Scope Rules 75
7.3 Chained Package Clauses 77
7.4 Top-of-File Notation 77
7.5 Package Objects 78
7.6 Package Visibility 78
7.7 Imports 79
7.8 Imports Can Be Anywhere 80
7.9 Renaming and Hiding Members 80
7.10 Implicit Imports 80
Exercises 81
Chapter 8: Inheritance 85
8.1 Extending a Class 85
8.2 Overriding Methods 86
8.3 Type Checks and Casts 87
8.4 Protected Fields and Methods 88
8.5 Superclass Construction 88
8.6 Overriding Fields 89
8.7 Anonymous Subclasses 91
8.8 Abstract Classes 91
8.9 Abstract Fields 91
8.10 Construction Order and Early Definitions 92
8.11 The Scala Inheritance Hierarchy 94
8.12 Object Equality 95
Exercises 96
Chapter 9: Files and Regular Expressions 99
9.1 Reading Lines 100
9.2 Reading Characters 100
9.3 Reading Tokens and Numbers 101
9.4 Reading from URLs and Other Sources 102
9.5 Reading Binary Files 102
9.6 Writing Text Files 102
9.7 Visiting Directories 103
9.8 Serialization 104
9.9 Process Control 105
9.10 Regular Expressions 106
9.11 Regular Expression Groups 107
Exercises 107
Chapter 10: Traits 111
10.1 Why No Multiple Inheritance? 111
10.2 Traits as Interfaces 113
10.3 Traits with Concrete Implementations 114
10.4 Objects with Traits 115
10.5 Layered Traits 116
10.6 Overriding Abstract Methods in Traits 117
10.7 Traits for Rich Interfaces 118
10.8 Concrete Fields in Traits 118
10.9 Abstract Fields in Traits 119
10.10 Trait Construction Order 120
10.11 Initializing Trait Fields 122
10.12 Traits Extending Classes 123
10.13 Self Types 124
10.14 What Happens under the Hood 125
Exercises 127
Chapter 11: Operators 131
11.1 Identifiers 131
11.2 Infix Operators 132
11.3 Unary Operators 133
11.4 Assignment Operators 133
11.5 Precedence 134
11.6 Associativity 135
11.7 The apply and update Methods 135
11.8 Extractors 136
11.9 Extractors with One or No Arguments 138
11.10 The unapplySeq Method 138
Exercises 139
Chapter 12: Higher-Order Functions 143
12.1 Functions as Values 143
12.2 Anonymous Functions 144
12.3 Functions with Function Parameters 145
12.4 Parameter Inference 146
12.5 Useful Higher-Order Functions 146
12.6 Closures 148
12.7 SAM Conversions 149
12.8 Currying 149
12.9 Control Abstractions 150
12.10 The return Expression 152
Exercises 152
Chapter 13: Collections 155
13.1 The Main Collections Traits 156
13.2 Mutable and Immutable Collections 157
13.3 Sequences 158
13.4 Lists 159
13.5 Mutable Lists 160
13.6 Sets 161
13.7 Operators for Adding or Removing Elements 162
13.8 Common Methods 164
13.9 Mapping a Function 167
13.10 Reducing, Folding, and Scanning 168
13.11 Zipping 171
13.12 Iterators 172
13.13 Streams 173
13.14 Lazy Views 174
13.15 Interoperability with Java Collections 175
13.16 Threadsafe Collections 177
13.17 Parallel Collections 178
Exercises 179
Chapter 14: Pattern Matching and Case Classes 183
14.1 A Better Switch 184
14.2 Guards 185
14.3 Variables in Patterns 185
14.4 Type Patterns 186
14.5 Matching Arrays, Lists, and Tuples 187
14.6 Extractors 188
14.7 Patterns in Variable Declarations 188
14.8 Patterns in for Expressions 189
14.9 Case Classes 189
14.10 The copy Method and Named Parameters 190
14.11 Infix Notation in case Clauses 191
14.12 Matching Nested Structures 192
14.13 Are Case Classes Evil? 192
14.14 Sealed Classes 193
14.15 Simulating Enumerations 194
14.16 The Option Type 194
14.17 Partial Functions 195
Exercises 196
Chapter 15: Annotations 199
15.1 What Are Annotations? 200
15.2 What Can Be Annotated? 200
15.3 Annotation Arguments 201
15.4 Annotation Implementations 202
15.5 Annotations for Java Features 203
15.6 Annotations for Optimizations 206
15.7 Annotations for Errors and Warnings 210
Exercises 211
Chapter 16: XML Processing 213
16.1 XML Literals 214
16.2 XML Nodes 214
16.3 Element Attributes 216
16.4 Embedded Expressions 217
16.5 Expressions in Attributes 218
16.6 Uncommon Node Types 219
16.7 XPath-like Expressions 220
16.8 Pattern Matching 221
16.9 Modifying Elements and Attributes 222
16.10 Transforming XML 223
16.11 Loading and Saving 223
16.12 Namespaces 226
Exercises 227
Chapter 17: Type Parameters 231
17.1 Generic Classes 232
17.2 Generic Functions 232
17.3 Bounds for Type Variables 232
17.4 View Bounds 234
17.5 Context Bounds 234
17.6 The Manifest Context Bound 235
17.7 Multiple Bounds 235
17.8 Type Constraints 236
17.9 Variance 237
17.10 Co- and Contravariant Positions 238
17.11 Objects Can't Be Generic 240
17.12 Wildcards 241
Exercises 241
Chapter 18: Advanced Types 245
18.1 Singleton Types 246
18.2 Type Projections 247
18.3 Paths 248
18.4 Type Aliases 249
18.5 Structural Types 250
18.6 Compound Types 250
18.7 Infix Types 251
18.8 Existential Types 252
18.9 The Scala Type System 253
18.10 Self Types 254
18.11 Dependency Injection 255
18.12 Abstract Types 257
18.13 Family Polymorphism 259
18.14 Higher-Kinded Types 263
Exercises 265
Chapter 19: Parsing 269
19.1 Grammars 270
19.2 Combining Parser Operations 271
19.3 Transforming Parser Results 273
19.4 Discarding Tokens 274
19.5 Generating Parse Trees 275
19.6 Avoiding Left Recursion 276
19.7 More Combinators 277
19.8 Avoiding Backtracking 280
19.9 Packrat Parsers 280
19.10 What Exactly Are Parsers? 281
19.11 Regex Parsers 282
19.12 Token-Based Parsers 283
19.13 Error Handling 285
Exercises 286
Chapter 20: Actors 289
20.1 Creating and Starting Actors 290
20.2 Sending Messages 291
20.3 Receiving Messages 292
20.4 Sending Messages to Other Actors 293
20.5 Channels 294
20.6 Synchronous Messages and Futures 295
20.7 Thread Sharing 296
20.8 The Actor Life Cycle 299
20.9 Linking Actors 300
20.10 Designing with Actors 301
Exercises 302
Chapter 21: Implicits 305
21.1 Implicit Conversions 306
21.2 Using Implicits for Enriching Existing Libraries 306
21.3 Importing Implicits 307
21.4 Rules for Implicit Conversions 308
21.5 Implicit Parameters 309
21.6 Implicit Conversions with Implicit Parameters 310
21.7 Context Bounds 311
21.8 Evidence 312
21.9 The @implicitNotFound Annotation 313
21.10 CanBuildFrom Demystified 314
Exercises 316
Chapter 22: Delimited Continuations 319
22.1 Capturing and Invoking a Continuation 320
22.2 The Computation with a Hole 321
22.3 The Control Flow of reset and shift 322
22.4 The Value of a reset Expression 323
22.5 The Types of reset and shift Expressions 323
22.6 CPS Annotations 325
22.7 Turning a Recursive Visit into an Iteration 326
22.8 Undoing Inversion of Control 329
22.9 The CPS Transformation 332
22.10 Transforming Nested Control Contexts 334
Exercises 336
Index 339
