/****************************  Listing 1  ****************************/
/*******                                                       *******/
/******* Add this code to the declarations section of yref2.y, *******/
/*******             between the %{ and %} symbols             *******/
/*******                                                       *******/
/*********************************************************************/

struct symlist                     /*  Linked list for storing line numbers */
        {
        int line;                  /*  Line number for this instance */
        int decl;                  /*  Declaration = 1, reference = 0 */
        struct symlist *next;      /*  Pointer to next instance */
        };

struct tnode
        {
        char *word;                /*  Identifier */
        int count;                 /*  Total instances */
        struct symlist *first;     /*  Pointer to beginning of line list */
        struct symlist *current;   /*  Pointer to most recent line instance */
        struct tnode *left;        /*  Pointer to left node in tree */
        struct tnode *right;       /*  Pointer to right node in tree */
        };

struct tnode *root;
int yn_decl = 0;           /*  Declaration = 1, reference = 0 */

struct tnode *addtree(struct tnode *, char *);
void treeprint(struct tnode *);
void listprint(struct symlist *, int );
struct tnode *talloc(void);
struct symlist *lalloc(void);