Example Token Data Structure

typedef struct tokn {
  int   tokentype;  /* OPERATOR, etc */
  int   basicdt; /* INTEGER REAL POINTER */
  struct symtbr * symtype;
  struct symtbr * symentry;
  struct tokn *operands;
  struct tokn *link;
  union { char  tokenstring[16];
          int   which;
          long  intnum;
          float realnum; } tokenval;
  } TOKENREC, *TOKEN;

symtype	pointer to type in symbol table
symentry	pointer to variable in symbol table
operands	down pointer to operand tokens
link	side pointer to sibling token
whichval	integer code: which operator, etc.
	defined as tokenval.which
stringval	string constant or variable name
intval	value of integer constant
realval	value of real constant