Lambda the Ultimate

Generic programming — Or: write everything once

Ralf Hinze summarizes polytypic programming, with a focus on Generic Haskell. He discusses:

• Generic functions on types
• Generic functions on type constructors
• Generic types

In addition to the usual generic equality and serialization, he mentions fold and map (though not by name), along with a dozen other ideas that use polytypism. He also notes that the Generic Haskell experiment will be continued and integrated into a "standard Haskell compiler".