Scala in Depth

Chapter 5. Using implicits to write expressive code

 

In this chapter

• Introduction to implicits
• Mechanics of the implicit resolution system
• Using implicits to enhance classes
• Using implicits to enforce scope rules

 

The implicit system in Scala allows the compiler to adjust code using a well-defined lookup mechanism. A programmer in Scala can leave out information that the compiler will attempt to infer at compile time. The Scala compiler can infer one of two situations:

• A method call or constructor with a missing parameter.
• Missing conversion from one type to another type. This also applies to method calls on an object that would require a conversion.

In both of these situations, the compiler follows a set of rules to resolve missing data ...