Symbol ranking text compressor v0.2
P M Fenwick 9 September 1996.

The basis of symbol-ranking compression is that we have a list of symbols ordered according to their likelihood in the current context. On compression, each input symbol is translated into its index in that list, with the most likely symbol 'Rank-0', the next 'Rank-1', and so on. On expansion, the received index is used to get the symbol from the list. This version is intended for high speed rather than good compression.