Free Scala programming books and guides

摘自：http://stackoverflow.com/tags/scala/info

 

About scala

Scala is a general purpose programming language principally targeting the Java Virtual Machine. Designed to express common programming patterns in a concise, elegant, and type-safe way, it fuses both imperative and functional programming styles. Its key features are:

• Static typing
• Advanced type system with type inference and declaration-site variance
• Function types (including anonymous) which support lexical closures
• Pattern-matching
• Implicit parameters and conversions which support the typeclass and enrich-my-library patterns
• Mixin composition
• Full interoperability with Java
• Powerful concurrency constructs
• Advanced language constructs such as delimited continuations and an experimental macro system

For more information, see the official Scala Introduction and Scala Documentation.

To search for Scala symbols such as "=>" in Stack Overflow, you can use symbolhound search.

To search Scala documentation, you can use scalex.

Free Scala programming books and guides

• Programming in Scala, First Edition
• Scala By Example (PDF)
• A Scala Tutorial for Java programmers
• Scala for Java refugees
• Scala School
• Scala Tutorials
• Scala Tour
• Scala for the Impatient (first part available for free at http://typesafe.com/resources/free-books)

Stack Overflow Scala Tutorial

1. Introduction to Scala
   • What's so great about Scala?
2. Variables/values
   • Difference between val and var
   • val-mutable versus var-immutable
   • How to assign vals correctly?
   • Multiple variable declarations
   • Lazy vals
     • What do they do?
     • How are they implemented?
   • Identifier rules
3. Methods
   • Equal sign in methods
   • Operator notation and the rules
   • Multiple ways to define a method/function (leave parentheses in method calls)
   • Unary operators
   • Multiple parameter lists
   • Right-associative method names
   • Side effect free methods
     • Missing parentheses at methods
     • Why no i++ in Scala?
   • How to mix punctuation with alphanumeric characters in method names?
   • Shortcut methods (+=, -=, *=, ...)
   • List of "magic method" names (apply, unapply/unapplySeq, update)
   • Named arguments / optional parameters
   • Type inference in return type
   • Difference between ## and hashCode
4. Literals, statements and blocks
   • Difference between block and statement
   • Weak conformance
   • Symbols
   • Difference between braces and parentheses
   • Dereference keyword (backtick usage)
   • Local definitions
   • Uses of an underscore
   • Identifier rules
   • Punctuation (operator) overview
5. Loops/recursion
   • Loop
     • Simple loop
     • Break out of a loop
     • How to call a function x times
   • Tail recursion
     • What is tail recursion?
     • How to write tail recursive code?
     • Performance
     • Optimization rules
   • Trampolining
6. Data structures / Collections
   • Collections design tutorial
   • Collection standard practice
   • Immutable Collections
     • List
     • Vector
     • Range
     • Tuple
     • Map
     • Set
   • Mutable Collections
     • Array and multi-dimensional Arrays
     • Buffer
     • How to use mutable Collections?
     • Mutating a mutable collection using map?
   • Lazy Collections
     • Why are they needed?
     • View
     • Iterator
     • Stream
     • Streams vs Views vs Iterators
     • Return a lazy collection
   • Parallel Collections
     • How do they work?
     • Is is possible to change their behavior?
   • Conversions
     • Casting and ascription
     • Java Collection to Scala Collection and vice versa
     • Convert to another Collections
     • breakout
   • Memory footprint
   • How are Scala collections able to return the correct collection type from an operation?
7. For-comprehension
   • Explanation
   • nested for-expressions
   • Use for inside expressions
   • yield is not a return
8. Enumeration
   • Explanation
9. Pattern matching
   • Explanation
   • Value binding (x @ X) / type binding (x: X)
   • How to do a multi-match
   • Guards
   • How to match variables or values?
   • How is pattern match implemented under the hood?
   • Exhaustive pattern
   • Assignment via pattern
   • Pattern match in for-expressions
   • Ignore cases / no default value
   • Conjunction
   • Pattern match PartialFunctions
   • Match Regex
   • Pattern matching with more than one match
10. Classes, objects and types
    • Difference between class and object
    • Why is object a Singleton?
    • Why are singleton objects more object orientated?
    • Companion objects
    • Difference between class and type
    • What's the difference between a class with a companion object and a class and object with the same name?
    • Static initializer
    • Constructor overloading
    • Static data in non-objects
    • How to get the static/runtime type of a class
    • Type projection (A#B)
11. Packages, imports and visibility identifiers
    • Imports
      • Multiple imports / import renames / hide imports
      • Shorthand imports
      • Local imports
    • Packages
      • Nested packages / multiple package definitions
      • Package objects
    • Visibility
      • Explanation
      • Private constructors
      • Private variables
12. Inheritance
    • Explanation
    • Early initializer
13. Extractors
    • Explanation (Example: conjunctions)
    • Infix notation for type parameters (X[A, B] => A X B)
14. Case classes
    • Explanation
    • case classes vs. enums
    • What are the disadvantages to declaring Scala case classes
    • compiler generated code for case classes
15. Parameterized types
    • How to declare them?
    • Upper / lower bounds
    • Unify numerics
    • How to get around type erasure?
    • Abstract Types vs Generics
    • Variances
16. Traits
    • Usage
    • Mixin multiple traits
    • Traits vs abstract classes
    • What does trait A <: B mean?
    • Linearization
    • Mixin a trait with overridden behavior
    • Dynamic mixins
    • How are they implemented under the hood?
    • How to access one of multiple traits of superclass?
17. Self references
    • Unify types
    • Self reference naming
    • Multiple self references
    • Difference between self references and subtyping
18. Error handling
    • Exceptions
      • Explanation
      • Stand-alone try block
      • Ignore an exception
      • Try-catch-generalization
    • Option
      • Explanation
    • Either
      • Explanation
      • How to use them?
    • What to use?
19. Type handling
    • Context ([A : B]) and view bounds ([A <% B])
    • Types
      • Non-Nullable type
      • Existential type
      • Structural type ("duck typing")
      • Path-dependent type
      • Union types (type disjunction)
      • Monad type
      • Compound type in structural type
      • Compound type in self references
      • Compound type in parameterized type
    • Advantages of Scalas type system
20. Annotations
    • What are they?
    • How to use them?
21. Functions/Function literals
    • Explanation
    • Functions vs methods
    • Pass functions
    • Currying
    • PartialFunction
    • Placeholder syntax and their replacement rules
    • Placeholder syntax with right-associative methods
    • Difference between => Type, () => Type and Unit => Type
    • Functional Quicksort
    • Keyword return in higher order functions and performance problem with that
    • Function composition
    • Closures in Scala
22. Type safety
    • Manifest
      • Explanation
      • How do they work?
      • Are Manifests possible in constructors?
    • Generalized Type Constraints (<:<, <%<, =:=)
    • Path-Dependent Types
    • Enforce type difference
    • Enforce no type bounds
23. Implicits
    • Implicit definitions / parameters
    • Implicit conversions / Monkey patching
    • Identifier implicitly
    • Where does Scala look for implicits?
    • Should implicits used?
    • Style of implicits
    • Convert multiple values with one implicit conversion
    • Chaining implicits
24. Reflection
    • What is a TypeTag and how do I use it?
    • How to work with Reflection?
25. Enrich-my-library pattern (formerly known as pimp-my-library)
    • Explanation
    • CanBuildFrom
    • Returning original types while extending the Collection API
26. Concurrency overview
27. Actors
    • Differences between Actor implementations
    • Design Patterns
    • Worst practices
28. Use Java from Scala and vice versa
    • Iterate over Java collection
    • Migrate Java to Scala
    • Transparent conversions useful?
    • Using Scala traits with implemented methods in Java
    • How to work with javap for Scala/Java interop?
    • Scala signatures
    • How does abstract override work internally?
29. XML literals
    • Explanation
30. Scala Swing
    • Explanation
    • Examples
31. Type Programming
    • Overview
32. Functional Scala
    • Is immutability expensive?
    • Is Scala functional programming slower than traditional coding?
    • OOP in a purely FP context?
    • Continuations
      • Explanation
      • How to activate them?
    • Design patterns for functional-oo hybrid languages?
    • Type programming
    • Higher kinded types
    • Type lambdas (SomeType[({type λ[α] = Either[A, α]})#λ])
    • Virtual Classes
    • forall in Scala

Further learning

1. Learning Resources
   • How can I learn more about Scala's type relationships?
   • Scala Cheat Sheet
   • Good examples of idiomatic scala code?
   • Solidifying Scala knowledge
2. REPL
   • How does it work behind the scenes?
3. Working with scalac and scala
   • Show syntax trees
   • Meaning of !# (bang-pound) in a shell script?
4. Operator precedence
   • Specification rules
   • Actual scalac precedence implementation
   • Understanding precedence rules in practice
5. Scala blogs to follow
6. Scala style
   • Scala Style Guide
   • Elements of Scala Style
   • Effective Scala
7. Functional Programming Principles in Scala, a free functional programming course on Coursera taught by Martin Odersky, the creator of Scala
8. Principles of Reactive Programming, a free reactive functional programming course on Coursera taught by Martin Odersky, Erik Meijer, Roland Kuhn.