Effective Haskell: Solving Real-World Problems with Strongly Typed Functional Programming

Cover
Table of Contents
Acknowledgments
Foreword
Introduction
	Why Choose Haskell?
	Why This Book
	How to Read This Book
1. Getting Started with Haskell
	Exploring Haskell Interactively
	Writing Your First Haskell Program
	Formatting Haskell Code
	Creating New Variables
	Writing Functions
	Precedence, Operators, and Fixity
	Creating Local Variables Using Let Bindings
	Running Code Conditionally Using Branches
	Looping
	Summary
	Exercises
2. Working with Lists
	Writing Code Using Lists
	Destructuring Values with Pattern Matching
	Understanding How Programs Are Evaluated
	Hands-On with Infinite Fibonacci Numbers
	Summary
	Exercises
3. Getting Started with Types
	Working with Basic Haskell Types
	Annotating Values with Type Information
	Looking Up Type Information
	Writing Type Annotations for Functions
	Reading Type Errors
	Working with Polymorphic Functions
	Exploring the Type Space of an Application with Undefined
	Getting Help from Type Holes
	Looking at the Type of main
	Summary
	Exercises
4. Creating New Types
	Creating Data Types and Records
	Creating Sum Types
	Creating Inductively Defined Data Structures
	Building a Calculator
	Functions as Values
	Creating Type Aliases
	Summary
	Exercises
5. Creating And Structuring Haskell Projects
	Creating Haskell Projects
	Using Code from Other Modules
	Creating Your Own Modules
	Choosing What to Export
	Documenting Modules
	Summary
	Exercises
6. Type Classes
	Using Ad Hoc Polymorphism with Type classes
	Specifying Type Class Instances with Type Applications
	Wrapping Types with Newtype
	Understanding Higher Kinded Types and Polymorphism
	Deriving Instances
	Deriving More Things
	Summary
	Exercises
7. Understanding IO
	Talking About IO
	Performing IO in a Pure, Lazy Language
	Ordering and Combining IO Actions
	Independently Sequencing IO Actions
	Mapping IO Values with fmap
	Running IO in Real Applications
	Summary
	Exercises
8. Working with the Local System
	Building Applications with IO
	Procedural Shell, Functional Core
	Creating a Pager
	Viewing the Contents of an ASCII or UTF8 Encoded Text File
	Viewing Text One Page at a Time
	Adding a Status Line with Metadata
	Showing the Status Bar and Refactoring runHCat
	Summary
	Exercises
9. Introducing Monads
	Mapping Functors
	Applying Applicatives
	Working with the Monad Type Class
	Understanding the Laws of the Land
	Using the Functor Laws
	Using the Monad Laws
	Using the Applicative Laws
	Summary
	Exercises
10. Mutable Data in the Real World
	Using Mutable References in a Pure Language
	Working with IORefs
	Building a Basic Metrics System with IORefs
	Dealing with Laziness and IO
	Summary
	Exercises
11. Serializing Heterogenous Data
	Heterogenous Data in Haskell
	A First Pass at a File Archiver
	Serializing with Type Classes
	Building a List of FileData Values
	Summary
	Exercises
12. Deserializing Heterogenous Data
	Extracting Heterogenous Values from the Archive
	Deserialization as Parsing
	Creating a Parsing Function
	Building a Monadic Parser
	Parsing a List of Values
	Adding a Monad Instance
	Adding a MonadFail Instance
	Summary
	Exercises
13. Building Applications with Many Effects
	Revisiting the Parsing Problem
	Handling Errors in Other Computations
	State, Transformed
	Stacking Transformers Effectively
	Building a File Archiver
	Summary
	Exercises
14. Building Efficient Programs
	Building a Naive Spellchecker
	Memoizing editDistance
	Internal Mutability with ST
	Optimizing Memory Layout with Vectors
	The Fastest Edit Distance
	Summary
	Exercises
15. Programming with Types
	What Is Type Level Programming?
	Types and Kinds
	Functions from Types to Types
	GADTs: Functions from Terms to Types
	Type Classes: Functions from Types to Terms
	Summary
	Exercises
Index
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