Post on 06-Mar-2018
Programming Ruby 1.9The Pragmatic Programmers Guide
Dave Thomas
with Chad Fowler
and Andy Hunt
The Pragmatic BookshelfRaleigh, North Carolina Dallas, Texas
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Contents
FOREWORD 16
PREFACE 17
ROAD MAP 22
PART IFACETS OF RUBY
1 GETTING STARTED 25The Command Prompt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Installing Ruby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Running Ruby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Ruby Documentation: RDoc and ri . . . . . . . . . . . . . . . . . . . . . . . . 32
2 RUBY.NEW 35Ruby Is an Object-Oriented Language . . . . . . . . . . . . . . . . . . . . . . 35
Some Basic Ruby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Arrays and Hashes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Control Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Regular Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Blocks and Iterators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Reading and Riting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Command-Line Arguments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Onward and Upward . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3 CLASSES, OBJECTS, AND VARIABLES 50Objects and Attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Classes Working with Other Classes . . . . . . . . . . . . . . . . . . . . . . . 58
Access Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Report erratum4
http://books.pragprog.com/titles/ruby3/errata/add?pdf_page=4
CONTENTS 5
4 CONTAINERS, BLOCKS, AND ITERATORS 67Blocks and Iterators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Containers Everywhere . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
5 SHARING FUNCTIONALITY: INHERITANCE, MODULES, AND MIXINS 91Inheritance and Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Mixins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Iterators and the Enumerable Module . . . . . . . . . . . . . . . . . . . . . . . 100
Composing Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Inheritance, Mixins, and Design . . . . . . . . . . . . . . . . . . . . . . . . . 104
6 STANDARD TYPES 106Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Strings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
7 REGULAR EXPRESSIONS 117What Regular Expressions Let You Do . . . . . . . . . . . . . . . . . . . . . . 117
Rubys Regular Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Digging Deeper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Pattern-Based Substitution . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Advanced Regular Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . 130
8 MORE ABOUT METHODS 137Defining a Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Calling a Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
9 EXPRESSIONS 146Operator Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Miscellaneous Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Conditional Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Case Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Variable Scope, Loops, and Blocks . . . . . . . . . . . . . . . . . . . . . . . . 165
10 EXCEPTIONS, CATCH, AND THROW 167The Exception Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Handling Exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Raising Exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
Catch and Throw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
11 BASIC INPUT AND OUTPUT 176What Is an IO Object? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Opening and Closing Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Reading and Writing Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Talking to Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
Report erratum
http://books.pragprog.com/titles/ruby3/errata/add?pdf_page=5
CONTENTS 6
12 FIBERS, THREADS, AND PROCESSES 184Fibers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
Multithreading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Controlling the Thread Scheduler . . . . . . . . . . . . . . . . . . . . . . . . . 190
Mutual Exclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
Running Multiple Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
13 UNIT TESTING 198The Testing Framework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
Structuring Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Organizing and Running Tests . . . . . . . . . . . . . . . . . . . . . . . . . . 206
RSpec and Shoulda . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
14 WHEN TROUBLE STRIKES 220Ruby Debugger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Interactive Ruby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
Editor Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
But It Doesnt Work! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
But Its Too Slow! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
PART IIRUBY IN ITS SETTING
15 RUBY AND ITS WORLD 233Command-Line Arguments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
Program Termination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Environment Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
Where Ruby Finds Its Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . 238
RubyGems Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
The Rake Build Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
Build Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
16 NAMESPACES, SOURCE FILES, AND DISTRIBUTION 249Namespaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Organizing Your Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
Distributing and Installing Your Code . . . . . . . . . . . . . . . . . . . . . . 258
17 CHARACTER ENCODING 264Encodings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
Source Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
Transcoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Input and Output Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Default External Encoding . . . . . .