Ranges usages

[Rob T]

FYI

I'm getting these compile errors, must be the compiler flags I'm 
using?

source/main.d(19): Error: cannot implicitly convert expression 
(dictionary.length() - 1LU) of type ulong to int
source/main.d(48): Error: cannot implicitly convert expression 
(dictionary.length() - 1LU) of type ulong to int


17        } else {
18            result ~= dictionary[w];
19**          dictionary[wc] = dictionary.length - 1;
20            w = [ch];
21        }


46        } else {
47            result ~= dictionary[w];
48**          dictionary[wc] = dictionary.length - 1;
49            w = Slice(i, i + 1);
50        }

--rt