code: def charindex(self, line, column):
          
          #Make sure that we have chars and lines to work from if this
          #gets called before linenum() does.
          if len(self._lines) == 0:
              self.linenum(1)
  
          if line < len(self._chars):
              return self._chars[line - 1] + column
          else:
              return len(self.refstring)
docs: Gets the absolute character index of the line and column
          in the continuous string.