I believe I have got the first Scheme application past Apple review into the iTunes App Store. It is yet another Reversi clone, called Reverso. It is a combination of 90% Scheme and 10% Objective-C, written with Gambit-C Scheme. James Long has already shown how to compile Gambit-C for the iPhone, and I started from there. My Scheme code is compiled to C by Gambit and later by GCC to produce native ARM code, bundled in a static library, which is ok with the iPhone SDK license agreement. The Objective-C then calls the library as a pure C library. The Scheme code deals with position evaluation, alpha-beta pruning, transposition tables, move legality, different strategies and so on. The Objective-C code deals with sound, animations, GUI, user preferences, basically everything that calls the iPhone OS API. Reversi was chosen because I like strategy games and it is much more algorithmic than artistic, and I am no artist.
The performance of the code is excellent. I used some Gambit-specific declarations, only fixnum arithmetic, pre-allocated a large heap, and called the garbage-collector every time the user needed to think. The search is not memory intensive, but the transposition tables are. I did not write a specific hash function but relied on Gambit-C’s table type. The boards used during search were retrieved from a pool (the newest Gambit-C has made subu8vector-move! a public API), so they did not put pressure on the garbage-collector. In the end it was a very successful experiment. Developing with Scheme is orders of magnitude more productive than with most other languages. Gambit-C is also one of the best Scheme compilers out there, and made my job a lot easier.
Numbness, especially persistent is a strong warning sign. Don't ignore it like I did!
First off, you should see a qualified physical therapist (someone who knows the wrist) immediately. She will help you change your setup to be more ergonomic and probably give you some light exercises. Another benefit is that she can measure the problem, allowing you to track your progress and the effectiveness of any treatment.
Next, I can recommend a few products that have really helped me out:
Number one, make sure your keyboard is big enough if you're using a laptop. I used to use an IBM Thinkpad X31, the keyboard was way too small and that was the beginning of my serious wrist problems.
Next, for mice, I heartily recommend the Evoluent Vertical Mouse. There is a bit of a price premium, but these are great optical mice for those with wrist issues. I have two, one for right and left that I switch between if I feel any pain or tingling.
For keyboards, I've stuck with the Microsoft Natural Keyboard Pro. Once you have it at the right height, and you're using it at the right angle, this makes a fine keyboard.
Best of luck. I got over this completely and so can you.
Reverso: http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftwa...
Gambit Scheme: http://dynamo.iro.umontreal.ca/~gambit/wiki/index.php/Main_P...
James Longster - Scheme on the iPhone: http://jlongster.com/blog/2009/06/17/write-apps-iphone-schem...