# File lib/cassiopee.rb, line 359
        def indexFile(f)
         # Parse file, map letters to reduced alphabet
         # Later on, use binary map instead of ascii map
         # Take all suffix, order by length, link to position map on other file
         # Store md5 for easier compare? + 20 bytes per suffix
            @sequence = readSequence(f)
            clear()
            @min_position = 0
                @max_position = 0
        end