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## Type_Families_Sealed_Traits_and_Exhaustive_Pattern_Matching_in_Scala.md

      
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              November 18, 2018 17:45
                — forked from mattbarackman/Type_Families_Sealed_Traits_and_Exhaustive_Pattern_Matching_in_Scala.md
            
              
                A brief lesson on Type Families, Sealed Traits, and Exhaustive Pattern Matching in Scala
              
          
    Scala: Type Families, Sealed Traits, and Exhaustive Pattern Matching

By: Matt Barackman
What is a Type Family?

A collection of objects or case classes that share a sealed trait.
In the example below, the type family would be a collection of traffic light colors with Red, Yellow, and Green as member objects.

  
## gist:9d27a92c3cb9537146a16ffe1ba55799
scala> import shapeless._, record._
import shapeless._
import record._

scala> case class Person(name: String, address: String, age: Int)
defined class Person

scala> val joe = Person("Joe", "Brighton", 33)
joe: Person = Person(Joe,Brighton,33)
	scala> import shapeless._, record._
	import shapeless._
	import record._

	scala> case class Person(name: String, address: String, age: Int)
	defined class Person

	scala> val joe = Person("Joe", "Brighton", 33)
	joe: Person = Person(Joe,Brighton,33)