implementing-type-classes

scala oops context-abstractions

Type classes

A type class or trait is an abstract class taking a generic type.

trait UtilMath[T]:
    def add(x: T, y: T): T

So, UtilMath is a type class.

Implementing a Type class

A type classes can be implemented using two methods

1. Extending the type class using extends
2. Creating a context using given with

Extending a type class

object StringMath extends UtilMath[String]:
    def add(x: String, y: String): String = x + y

given with

given UtilMath[String] with
    def add(x: String, y: String): String = x + y

Now, UtilMath[String] will be implicitly inferred by the compiler.

summon[UtilMath[String]].add("hello ", "world")

Read about given instance for given keyword.

References

1. Implementing type classes