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Programming Scala

Cover of Programming Scala by Dean Wampler... Published by O'Reilly Media, Inc.
  1. Programming Scala
    1. SPECIAL OFFER: Upgrade this ebook with O’Reilly
    2. A Note Regarding Supplemental Files
    3. Foreword
    4. Preface
      1. Welcome to Programming Scala
      2. Conventions Used in This Book
      3. Using Code Examples
      4. Safari® Books Online
      5. How to Contact Us
      6. Acknowledgments
    5. 1. Zero to Sixty: Introducing Scala
      1. Why Scala?
      2. Installing Scala
      3. For More Information
      4. A Taste of Scala
      5. A Taste of Concurrency
      6. Recap and What’s Next
    6. 2. Type Less, Do More
      1. In This Chapter
      2. Semicolons
      3. Variable Declarations
      4. Method Declarations
      5. Inferring Type Information
      6. Literals
      7. Tuples
      8. Option, Some, and None: Avoiding nulls
      9. Organizing Code in Files and Namespaces
      10. Importing Types and Their Members
      11. Abstract Types And Parameterized Types
      12. Reserved Words
      13. Recap and What’s Next
    7. 3. Rounding Out the Essentials
      1. Operator? Operator?
      2. Methods Without Parentheses and Dots
      3. Domain-Specific Languages
      4. Scala if Statements
      5. Scala for Comprehensions
      6. Other Looping Constructs
      7. Conditional Operators
      8. Pattern Matching
      9. Enumerations
      10. Recap and What’s Next
    8. 4. Traits
      1. Introducing Traits
      2. Stackable Traits
      3. Constructing Traits
      4. Recap and What’s Next
    9. 5. Basic Object-Oriented Programming in Scala
      1. Class and Object Basics
      2. Parent Classes
      3. Constructors in Scala
      4. Nested Classes
      5. Visibility Rules
      6. Recap and What’s Next
    10. 6. Advanced Object-Oriented Programming In Scala
      1. Overriding Members of Classes and Traits
      2. Companion Objects
      3. Case Classes
      4. Equality of Objects
      5. Recap and What’s Next
    11. 7. The Scala Object System
      1. The Predef Object
      2. Classes and Objects: Where Are the Statics?
      3. Sealed Class Hierarchies
      4. The Scala Type Hierarchy
      5. Linearization of an Object’s Hierarchy
      6. Recap and What’s Next
    12. 8. Functional Programming in Scala
      1. What Is Functional Programming?
      2. Functional Programming in Scala
      3. Recursion
      4. Tail Calls and Tail-Call Optimization
      5. Functional Data Structures
      6. Traversing, Mapping, Filtering, Folding, and Reducing
      7. Pattern Matching
      8. Partial Functions
      9. Currying
      10. Implicits
      11. Implicit Function Parameters
      12. Call by Name, Call by Value
      13. Lazy Vals
      14. Recap: Functional Component Abstractions
    13. 9. Robust, Scalable Concurrency with Actors
      1. The Problems of Shared, Synchronized State
      2. Actors
      3. Actors in Scala
      4. Traditional Concurrency in Scala: Threading and Events
      5. Recap and What’s Next
    14. 10. Herding XML in Scala
      1. Reading XML
      2. Writing XML
      3. Recap and What’s Next
    15. 11. Domain-Specific Languages in Scala
      1. Internal DSLs
      2. External DSLs with Parser Combinators
      3. Recap and What’s Next
    16. 12. The Scala Type System
      1. Reflecting on Types
      2. Understanding Parameterized Types
      3. Variance Under Inheritance
      4. Type Bounds
      5. Nothing and Null
      6. Understanding Abstract Types
      7. Path-Dependent Types
      8. Value Types
      9. Self-Type Annotations
      10. Structural Types
      11. Existential Types
      12. Infinite Data Structures and Laziness
      13. Recap and What’s Next
    17. 13. Application Design
      1. Annotations
      2. Enumerations Versus Pattern Matching
      3. Thoughts On Annotations and Enumerations
      4. Using Nulls Versus Options
      5. Exceptions and the Alternatives
      6. Scalable Abstractions
      7. Effective Design of Traits
      8. Design Patterns
      9. Better Design with Design By Contract
      10. Recap and What’s Next
    18. 14. Scala Tools, Libraries, and IDE Support
      1. Command-Line Tools
      2. Build Tools
      3. Integration with IDEs
      4. Test-Driven Development in Scala
      5. Other Notable Scala Libraries and Tools
      6. Java Interoperability
      7. Java Library Interoperability
      8. Recap and What’s Next
    19. A. References
    20. Glossary
    21. Index
    22. About the Authors
    23. Colophon
    24. SPECIAL OFFER: Upgrade this ebook with O’Reilly

Reserved Words

Table 2-4 lists the reserved words in Scala, which we sometimes call “keywords,” and briefly describes how they are used (see [ScalaSpec2009]).

Table 2-4. Reserved words

WordDescriptionSee …


Makes a declaration abstract. Unlike Java, the keyword is usually not required for abstract members.

Class and Object Basics


Start a case clause in a match expression.

Pattern Matching


Start a clause for catching thrown exceptions.

Using try, catch, and finally Clauses


Start a class declaration.

Class and Object Basics


Start a method declaration.

Method Declarations


Start a do...while loop.

Other Looping Constructs


Start an else clause for an if clause.

Scala if Statements


Indicates that the class or trait that follows is the parent type of the class or trait being declared.

Parent Classes


Boolean false.

The Scala Type Hierarchy


Applied to a class or trait to prohibit deriving child types from it. Applied to a member to prohibit overriding it in a derived class or trait.

Attempting to Override final Declarations


Start a clause that is executed after the corresponding try clause, whether or not an exception is thrown by the try clause.

Using try, catch, and finally Clauses


Start a for comprehension (loop).

Scala for Comprehensions


Used in existential type declarations to constrain the allowed concrete types that can be used.

Existential Types


Start an if clause.

Scala if Statements


Marks a method as eligible to be used as an implicit ...

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