6.12

1.3 Lenses on User-Defined Datatypes

In addition to the built-in lenses, lens provides utilities for construcing new lenses for user-defined datatypes. This section covers the utilities for creating lenses for Racket structs, as well as the general lens constructors for making arbitrary lenses.

    1.3.1 Structures

    1.3.2 Constructing Entirely New Lenses