Swindle

Swindle extends Racket with many additional features. The main feature that started this project is a CLOS-like object system based on Tiny-CLOS from Xerox, but there is a lot more.

Some documentation is available at http://barzilay.org/Swindle/.

1 Features

The following is a high-level description of major features provided by Swindle. For every feature, the file that provides it is specified, if only a subset of the system is needed.

• Some basic syntax extensions, including lambda &-keywords, and improved define and let forms. (Available separately using swindle/base)

• Generic setters with set!, additional useful mutation forms: pset!, shift!, rotate!, and some simple ones like inc!, and push!. (Available separately using swindle/setf, where the names setf! and psetf! are used to avoid changing the Racket form)

• Easy macro-defining macros — simple syntax-rules macros with defsubst, and a generic defmacro utility, all with a local let... form, and extended to easily create symbol macros. (swindle/misc)

• A collect macro that provides very sophisticated list comprehensions and much more. (swindle/misc)

• An echo mechanism which is an alternative to using format strings, and contains many useful features including a list iteration construct, and is easy to extend. (swindle/misc)

• A regexp-case syntax which is similar to a case on strings with easy access to submatches. (swindle/misc)

• A CLOS-like object system – based on Tiny CLOS, but with many extensions that bring it much closer to CLOS, and heavily optimized. Some added features include singleton and struct classes, applicable stand-alone methods, method-combination, and some MOP extensions. (Available without syntax bindings in swindle/tiny-clos)

• Good integration with the Racket implementation: primitive values have corresponding Swindle classes, and struct types can also be used as type specializers. A Swindle class will be made when needed, and it will reflect the struct hierarchy. In addition, structs can be defined with a Swindle-line defstruct syntax which will also make it possible to create these structs with make using keyword arguments. (swindle/tiny-clos and swindle/extra)

• Many hairy macros that make the object system much more convenient (CLOS has also a lot of macro code). Some of the macros (especially defclass) can be customized. (swindle/clos)

• Useful generic functions, including print-object which is used to display all objects. (swindle/extra)

• A match mechanism with a generic-like interface. (swindle/extra)

• The fun amb toy. (swindle/extra)

• A language that can easily create HTML, where the result is human-editable. (swindle/html)

• Customizable syntax: easy to add customized languages to DrRacket. (custom)

2 Libraries

Files marked with “module” provide a module by the same name, files marked with "language module" modify the language and should be used as an initial import for other modules. Most files (and especially all language modules) are useful by themselves, even without using the whole Swindle environment.

• swindle/base (language module) — Basic syntax extensions, mainly Lisp-like lambda argument &-keywords.

• swindle/setf (module) — Generic setters similar to setf in Lisp, and a few more useful macros.

• swindle/misc (module) — Lots of useful functionality bits, including everything from frequently useful Racket legacy libraries (mzlib/list, mzlib/etc, and mzlib/string).

• swindle/turbo (language module) — A module that packages functionality from swindle/base, swindle/setf (overriding set! with setf!), and swindle/misc.

• swindle/tiny-clos (module) — The core object system, based on Tiny CLOS from Xerox, but heavily modified, optimized and extended.

• swindle/clos (module) — Convenient macro wrappers for swindle/tiny-clos.

• swindle/extra (module) — Extra functionality on top of swindle/clos.

• swindle/swindle (language module) — The main Swindle environment module: packages swindle/tiny-clos, swindle/clos, and swindle/extra on top of swindle/turbo, and some more general definitions.

• swindle/info (module) — Compilation definitions.

• swindle/tool (module) — Setup for Swindle in DrRacket: makes some languages available in DrRacket, including custom Swindle-based languages.

• swindle/custom (module) — A sample file that demonstrates how to create a Swindle-based customized language; see the source for instructions.

• swindle/html (module) — A language for creating HTML.