Parse a string as an integer, encapsulating error handling. 

   None. 

   Variable  I/O  Description 
   --------  ---  -------------------------------------------------- 
   string     I   String representing an integer. 
   intval     O   Integer value obtained by parsing string. 

   string         is a string representing an integer.  Any string 
                  acceptable to the CSPICE routine nparsi_ is 
                  allowed. 

   intval         is the integer obtained by parsing string. 

   None. 

   The purpose of this routine is to enable safe parsing of integers 
   without the necessity of in-line error checking.  This routine is 
   based on the CSPICE routine nparsi_. 

   See the routine NPARSI for an examples of allowed strings. 

   None. 

   1) If the input string pointer is null, the error 
      SPICE(NULLPOINTER) will be signaled.

   2) If the input string does not contain at least one character, 
      the error SPICE(EMPTYSTRING) will be signaled.

   3) If the input string cannot be parsed, the error 
      SPICE(NOTANINTEGER) is signaled. 

   None. 

   N.J. Bachman       (JPL) 

   None. 

   -CSPICE Version 1.1.1, 26-AUG-1999 (NJB)  

      Header was updated to list string exceptions.

   -CSPICE Version 1.1.0, 08-FEB-1998 (NJB)  

       References to C2F_CreateStr_Sig were removed; code was
       cleaned up accordingly.  String checks are now done using
       the macro CHKFSTR.

   -CSPICE Version 1.0.0, 25-OCT-1997 (NJB)

   parse integer with encapsulated error handling