module LineCache

def remap_file_lines(from_file, to_file, range, start)
  range = (range..range) if range.is_a?(Fixnum)
  to_file = from_file unless to_file
  if @@file2file_remap_lines[to_file]
    # FIXME: need to check for overwriting ranges: whether
    # they intersect or one encompasses another.
    @@file2file_remap_lines[to_file] << [from_file, range, start]
  else
    @@file2file_remap_lines[to_file]  = [[from_file, range, start]]
  end
end