mevins at me dot com
The beautiful and the absurd, stories and songs, games and tools, facts and opinions, hopes and regrets. friends and foes.
mevins at me dot com
The beautiful and the absurd, stories and songs, games and tools, facts and opinions, hopes and regrets. friends and foes.
Download: Categories v0.1
Categories is an experimental object system, created to explore separating representation, behavior, and taxonomy into orthogonal parts.
Categories v0.1 is a preliminary version of Categories with the following features:
It's written in R5RS Scheme, with the intention that it should work in any R5RS-compliant implementation.
It provides most, but not all, of the defined features of Categories, including user-defined structure data types, polymorphic functions with multiple dispatch, and user-programable dispatching.
It includes an example implementation of the -flat- domain.
The R5RS implementation is simple, and not particularly efficient. With luck, though, it's small enough and portable enough that anyone who cares can make a more efficient implementation that takes advantage of some particular Scheme's features.
This release comes with just one domain: -flat-. The -flat- domain provides polymorphic functions and multiple dispatch, but no inheritance. I plan an additional release that will include two more domains: the -c3- domain will provide multiple inheritance and dispatch that uses the C3 class-linearization algorithm (see this paper for more about C3); the -pred- domain will provide predicate dispatch with C3 linearization of predicates.
Past that, I also plan a release of Categories for Gambit that takes advantage of some Gambit-specific features to make things faster and more convenient, and a release of Categories for Clojure.