Actually. As a programmer I'm usually more interested in how terms may be composed than how data is stored. Btw, this reminds me of a fascinating paper[1] on t

Actually. As a programmer I'm usually more interested in how terms may be composed than how data is stored. Btw, this reminds me of a fascinating paper[1] on the subject which "rather than interpreting type systems as categories, [it] describe them as functors from a category of typing derivations to a category of underlying terms. Then, turning this around, [it] explain how in fact any functor gives rise to a generalized type system, with an abstract notion of typing judgment, typing derivations and typing rules." [1] http://noamz.org/papers/funts.pdf http://noamz.org/papers/funts.pdf