When carefully selected and used, Domain-Specific Languages (DSLs) may simplify complex code, promote effective communication with customers, improve productivity, and unclog development bottlenecks. In Domain-Specific Languages, noted software development expert Martin Fowler first provides the information software professionals need to decide if and when to utilize DSLs. Then, where DSLs prove suitable, Fowler presents effective techniques for building them, and guides software engineers in choosing the right approaches for their applications.
This book's techniques may be utilized with most modern object-oriented languages; the author provides numerous examples in Java and C#, as well as selected examples in Ruby. Wherever possible, chapters are organized to be self-standing, and most reference topics are presented in a familiar patterns format.
Armed with this wide-ranging book, developers will have the knowledge they need to make important decisions about DSLs-and, where appropriate, gain the significant technical and business benefits they offer.
The topics covered include:
- How DSLs compare to frameworks and libraries, and when those alternatives are sufficient
- Using parsers and parser generators, and parsing external DSLs
- Understanding, comparing, and choosing DSL language constructs
- Determining whether to use code generation, and comparing code generation strategies
- Previewing new language workbench tools for creating DSLs
Autorentext
Martin Fowler is Chief Scientist at ThoughtWorks. He describes himself as "an author, speaker, consultant, and general loudmouth on software development. I concentrate on designing enterprise software-looking at what makes a good design and what practices are needed to come up with good design." Fowler's books include Patterns of Enterprise Application Architecture; UML Distilled, Third Edition; and (with Kent Beck, John Brant, and William Opdyke) Refactoring: Improving the Design of Existing Code. All are published by Addison-Wesley.
Inhalt
Preface xix
Part I: Narratives 1
Chapter 1: An Introductory Example 3
Gothic Security 3
The State Machine Model 5
Programming Miss Grant's Controller 9
Languages and Semantic Model 16
Using Code Generation 19
Using Language Workbenches 22
Visualization 24
Chapter 2: Using Domain-Specific Languages 27
Defining Domain-Specific Languages 27
Why Use a DSL? 33
Problems with DSLs 36
Wider Language Processing 39
DSL Lifecycle 40
What Makes a Good DSL Design? 42
Chapter 3: Implementing DSLs 43
Architecture of DSL Processing 43
The Workings of a Parser 47
Grammars, Syntax, and Semantics 49
Parsing Data 50
Macros 52
Chapter 4: Implementing an Internal DSL 67
Fluent and Command-Query APIs 68
The Need for a Parsing Layer 71
Using Functions 72
Literal Collections 77
Using Grammars to Choose Internal Elements 79
Closures 80
Parse Tree Manipulation 82
Annotation 84
Literal Extension 85
Reducing the Syntactic Noise 85
Dynamic Reception 86
Providing Some Type Checking 87
Chapter 5: Implementing an External DSL 89
Syntactic Analysis Strategy 89
Output Production Strategy 92
Parsing Concepts 94
Mixing-in Another Language 100
XML DSLs 101
Chapter 6: Choosing between Internal and External DSLs 105
Learning Curve 105
Cost of Building 106
Programmer Familiarity 107
Communication with Domain Experts 108
Mixing In the Host Language 108
Strong Expressiveness Boundary 109
Runtime Configuration 110
Sliding into Generality 110
Composing DSLs 111
Summing Up 111
Chapter 7: Alternative Computational Models 113
A Few Alternative Models 116
Chapter 8: Code Generation 121
Choosing What to Generate 122
How to Generate 124
Mixing Generated and Handwritten Code 126
Generating Readable Code 127
Preparse Code Generation 128
Further Reading 128
Chapter 9: Language Workbenches 129
Elements of Language Workbenches 130
Schema Definition Languages and Meta-Models 131
Source and Projectional Editing 136
Illustrative Programming 138
Tools Tour 140
Language Workbenches and CASE tools 141
Should You Use a Language Workbench? 142
Part II: Common Topics 145
Chapter 10: A Zoo of DSLs 147
Graphviz 147
JMock 149
CSS 150
Hibernate Query Language (HQL) 151
XAML 152
FIT 155
Make et al. 156
Chapter 11: Semantic Model 159
How It Works 159
When to Use It 162
The Introductory Example (Java) 163
Chapter 12: Symbol Table 165
How It Works 166
When to Use It 168
Further Reading 168
Dependency Network in an External DSL (Java and ANTLR) 168
Using Symbolic Keys in an Internal DSL (Ruby) 170
Using Enums for Statically Typed Symbols (Java) 172
Chapter 13: Context Variable 175
How It Works 175
When to Use It 176
Reading an INI File (C#) 176
Chapter 14: Construction Builder 179
How It Works 179
When to Use It 180
Building Simple Flight Data (C#) 180
Chapter 15: Macro 183
How It Works 184
When to Use It 192
Chapter 16: Notification 193
How It Works 194
When to Use It 194
A Very Simple Notification (C#) 194
Parsing Notification (Java) 195
Part III: External DSL Topics 199
Chapter 17: Delimiter-Directed Translation 201
How It Works 201
When to Use It 204
Frequent Customer Points (C#) 205
Parsing Nonautonomous Statements with Miss Grant's Controller (Java) 211
Chapter 18: Syntax-Directed Translation 219
How It Works 220
When to Use It 227
Further Reading 227
Chapter 19: BNF 229
How It Works 229
When to Use It 238
Chapter 20: Regex Table Lexer (by Rebecca Parsons) 239
How It Works 240
When to Use It 241
Lexing Miss Grant's Controller (Java) 241
Chapter 21: Recursive Descent Parser (by Rebecca Parsons) 245
How It Works 246
When to Use It 249
Further Reading 249
Recursive Descent and Miss Grant's Controller (Java) 250
Chapter 22: Parser Combinator (by Rebecca Parsons) 255
How It Works 256
When to Use It 261
Parser Combinators and Miss Grant's Controller (Java) 261
Chapter 23: Parser Generator 269
How It Works 269
When to Use It 272
Hello World (Java and ANTLR) 272
Chapter 24: Tree Construction 281
How It Works 281
When to Use It 284
Using ANTLR's Tree Construction Syntax (Java and ANTLR) 284
Tree Construction Using Code Actions (Java and ANTLR) 292
Chapter 25: Embedded Translation 299
How It Works 299
When to Use It 300
Miss Grant's Controller (Java and ANTLR) 300
Chapter 26: Embedded Interpretation 305
How It Works 305
When to Use It 306
A Calculator (ANTLR and Java) 306
Chapter 27: Foreign Code 309
How It Works 309
When to Use It 311
Embedding Dynamic Code (ANTLR, Java, and Javascript) 311
Chapter 28: Alternative Tokenization 319
How It Works 319
When to Use It 326…