McCullough writes a lot about generative structure, drawing on Chomsky and Piaget. While generative structure may no longer be a satisfactory explanation for human language, McCullough sees is as a principle of computing media.
“We have seen the role of structure, particularly generative structure, in several contexts already: the syntax of notation, the design of an interface, the constructions of a type, the essence of a medium. In each of these contexts, structure is revealed in transformation.” (p. 232 of Abstracting Craft)
We learn about the structure of digital media by playing with it – by playing with a software package and seeing what sorts of transformations happen when we try different features. (See the section “Generative Structure” in the chapter “Symbols” – starting page 98.)
This connects to play and games. Generative structures provide the constraints that make play possible and open the possibilities that give play meaning.
McCullough points to Digital Mantras by Steven Holtzman as a work that explores the history of generative structure.
For a good short exchange on Chomsky’s revolution see Searle and others at The New York Review of Books: CHOMSKY’S REVOLUTION.