Hello Andrew, Sunday, July 1, 2007, 1:18:16 PM, you wrote:
encoding is simple - make this traversal one time and store bit sequence for each symbol. for decoding, you can find length of longest symbol MaxBits and build table of 2^MaxBits elements which allows to find next symbol by direct lookup with next input MaxBits. faster algorithms use two-level lookup, first lookup with 9-10 bits is best when your encoded symbols are bytes
I see. So build a table of codes and bitmasks and test against that...
decodeSymbol = do n <- returnNextNBits MaxBits -- this operation doesn't forward input pointer! symbol <- table1 ! n bits <- table2 ! symbol skipNBits bits return symbol -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com