Herbarium Racketensis: a stroll through the woods (functional pearl)

Domain-specific languages are the ultimate abstraction, dixit Paul Hudak. But what abstraction should we use to build such ultimate abstractions? What is sauce for the goose is sauce for the gander: a language, of course! Racket is the ultimate abstraction-abstraction, a platform for quickly and easily building new ultimate abstractions. This pearl demonstrates Racket's power by taking a leisurely walk through the implementation of a DSL for Lindenmayer systems, the computational model par excellence of theoretical botany.