Summary

This chapter provides an introduction to most Contextual Abstractions topics, including:

• Extension Methods
• Given Instances and Using Clauses
• Context Bounds
• Given Imports
• Type Classes
• Multiversal Equality
• Implicit Conversions

These features are all variants of the core idea of term inference: given a type, the compiler synthesizes a “canonical” term that has that type.

A few more advanced topics aren’t covered here, including:

• Conditional Given Instances
• Type Class Derivation
• Context Functions
• By-Name Context Parameters
• Relationship with Scala 2 Implicits

Those topics are discussed in detail in the Reference documentation.