pathmap_partial (String)

         # File lib/rake.rb, line 107
    107:     def pathmap_partial(n)
    108:       dirs = File.dirname(self).pathmap_explode
    109:       partial_dirs =
    110:         if n > 0
    111:           dirs[0...n]
    112:         elsif n < 0
    113:           dirs.reverse[0...-n].reverse
    114:         else
    115:           "."
    116:         end
    117:       File.join(partial_dirs)
    118:     end