interfaces.md

Interfaces: using constrained generic types

Contents

• Constraining generic types using interfaces
• Implementing interfaces for specific contexts
• Using interfaces defined in the Prelude

Notes

• Interfaces in Idris are similar to type classes in Haskell, with some differences:

  • interfaces can be parameterized by values of any type, and are not limited to types or type constructors.
  • interfaces can have multiple implementations.

• Interfaces are limited to names introduced by either a data or record declaration, or primitive types.

• Interfaces in Idris can have any number of parameters, including zero. For example, interface Cast has two parameters.