          split string ?splitChars?
               Returns a list created  by  splitting  string  at  each
               character  that  is  in  the splitChars argument.  Each
               element  of  the  result  list  will  consist  of   the
               characters   from   string  between  instances  of  the
               characters in splitChars.  Empty list elements will  be
               generated  if  string  contains  adjacent characters in
               splitChars, or if the first or last character of string
               is  in  splitChars.   If  splitChars is an empty string
               then  each  character  of  string  becomes  a  separate
               element of the result list.  SplitChars defaults to the
               standard white-space characters.  For example,

                    split "comp.unix.misc" .

               returns "comp unix misc" and

                    split "Hello world" {}

               returns "H e l l o { } w o r l d".
