Tuesday, February 21, 2006

Emacspeak, SuDoKu And History

Here is a small enhancement to playing SuDoKu in Emacspeak. The feature is probably generally useful i.e., it's not specific to eyes-free interaction, but its presence encourages one to try different solution strategies.

Commands emacspeak-sudoku-history-push bound to m and emacspeak-sudoku-history-pop bound to M allow one to mark interesting states in the game and return to these prior states with a single keystroke. This means that when one is confronted with one of two choices, with no apparent additional information on which route to take, it becomes possible to push that state on to the history stack, try one of the alternatives and backtrack if necessary.