object-systems

See object-oriented-programming before the remainder of this page.

There are several common libraries for Scheme & particular Scheme implementations that claim to be 'object systems,' for varying definitions of 'object system.'

CLOS-Style

• Tiny-CLOS is Gregor Kiczales's variant of CLOS, the Common Lisp Object System, for quite portable Scheme. It implements a hierarchical class-based structure, a meta-object-protocol, and multiple dispatch, i.e. type dispatch occurs on every argument of a generic function invocation. There are several libraries & entire Scheme implementations based on it, including Eli Barzilay's Swindle, Gauche's object system, STklos, and MIT-Scheme-SOS and Meroon? to name a few.
• - Meroon? is another CLOS variant by Christian Queinnec, with a class-based hierarchy, multiple dispatch, and very much syntactic sugar. It is very static, however, in comparison to most CLOS variants; it is designed mostly with the intent of making compiler optimization easier at a high expense of the generally dynamic nature of most CLOS variants.
• GOOPS is GNU Guile's standard Object System. Its implementation is derived from STk-3.99.3 by Erick Gallesio and version 1.3 of Gregor Kiczales Tiny-Clos. It is designed in the spirit of tiny-clos, CLOS and stklos. It has multiple inheritance, generic functions with multi-method dispatch and a meta-object-protocol in the spirit of CLOS.

T Style

• YASOS is Ken Dickey's 'Yet Another Scheme Object System,' composed entirely of simple method dispatch for individual objects and nothing more. It is based on T's object system.

Prototype based

• Protobj is a prototype-based, single-delegation object system by Neil W. Van Dyke
• Prometheus is another very self-like, fully-featured object system
• TinyTalk has self-like delegation semantics https://launchpad.net/kend

Smalltalk Style

• OakLisp is a mixture of Scheme and Smalltalk. Everything is an object, methods are added for one type (so no multiple dispatch).
• ClosureTalk is a simple smalltalk like object system that uses closures to encapsulate data and methods
• LispMeObjects for LispMe. Written by Don Wells. It is a very minimal system, provides encapsulation and inheritance. is available at http://www.c2.com/cgi/wiki?LispMeObjects

jonathan-arkell

edit-hint I think that we should try to merge this list with the Jonathan Rees object-oriented-taxonomy. Just my thought.

Jorgen-Schäfer

I categorized those a bit. It would still be helpful to have a better description for each. From what I've seen from Oaklisp sources - that's not much - the object system seems to be quite CLOSy (make, add-method), but it might be something completely different...