★ /prog/ Challenge Vol. 5 ★

The challenge suggestion thread was too busy going nowhere, and I feel like writing some code, so here is a /prog/ challenge.

THE CHALLENGE:
Design a ^_toy programming language. You may implement either a compiler or interpreter, and you may write the implementation in any language of your choosing.

Post the source code to your implementation as well as programs in your language to accomplish ^{at least} two of the following tasks, plus one ``wild card'' program not listed here.

    • Factorial calculator
    • Fibonacci sequence generator
    • Prime number sieve (e.g. Eratosthenes, Atkin, etc.)
    • fgrep (output lines of input containing a given string)
    • Caesar cipher
    • Simple interactive calculator
    • Tic-tac-toe (AI not required)
    • The game of Nim (http://en.wikipedia.org/wiki/Nim)

Entries must be submitted prior to 2010-06-21 00:00, which gives one full week and two weekends. Judgment will be in three categories: presentation and cleverness of designed language, clarity of implementation, and overall usefulness/entertainment/trolling value of the ``wild card'' program.

Winner will receive ten Susscoins, to be transferred via /prog/mail.

>>142
There's no lisp because making lisp interpreters in lisp is easy if not cheating (no need for writing one's own parser, free AST representation, homoiconicity of the language giving you cheap low-level macros and making eval easy to describe in itself). The tricky part is making something new, which is what the challenge is. Reimplementing someone else's lisp is easy. Inventing some new unique semantics or ideas that nobody else had is something much harder and rarer in the Lisp world, because just about anything was already tried.
Trivial interpreters can be expressed in a single page of code.

Of course, some simple esolangs shouldn't be hard to make in it, but it's more fun to try to create something which you could find useful yourself.