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28 
29 /****************************************************************************
30  *  Author: Thomas E. Dickey            1998-on                             *
31  ****************************************************************************/
32 
33 /*
34 **	add_tries.c
35 **
36 **	Add keycode/string to tries-tree.
37 **
38 */
39 
40 #include <curses.priv.h>
41 
42 MODULE_ID("$Id: add_tries.c,v 1.8 2006/12/30 23:15:26 tom Exp $")
43 
44 #define SET_TRY(dst,src) if ((dst->ch = *src++) == 128) dst->ch = '\0'
45 #define CMP_TRY(a,b) ((a)? (a == b) : (b == 128))
46 
47 NCURSES_EXPORT(int)
48 _nc_add_to_try(TRIES ** tree, const char *str, unsigned code)
49 {
50     TRIES *ptr, *savedptr;
51     unsigned const char *txt = (unsigned const char *) str;
52 
53     T((T_CALLED("_nc_add_to_try(%p, %s, %u)"), *tree, _nc_visbuf(str), code));
54     if (txt == 0 || *txt == '\0' || code == 0)
55 	returnCode(ERR);
56 
57     if ((*tree) != 0) {
58 	ptr = savedptr = (*tree);
59 
60 	for (;;) {
61 	    unsigned char cmp = *txt;
62 
63 	    while (!CMP_TRY(ptr->ch, cmp)
64 		   && ptr->sibling != 0)
65 		ptr = ptr->sibling;
66 
67 	    if (CMP_TRY(ptr->ch, cmp)) {
68 		if (*(++txt) == '\0') {
69 		    ptr->value = code;
70 		    returnCode(OK);
71 		}
72 		if (ptr->child != 0)
73 		    ptr = ptr->child;
74 		else
75 		    break;
76 	    } else {
77 		if ((ptr->sibling = typeCalloc(TRIES, 1)) == 0) {
78 		    returnCode(ERR);
79 		}
80 
81 		savedptr = ptr = ptr->sibling;
82 		SET_TRY(ptr, txt);
83 		ptr->value = 0;
84 
85 		break;
86 	    }
87 	}			/* end for (;;) */
88     } else {			/* (*tree) == 0 :: First sequence to be added */
89 	savedptr = ptr = (*tree) = typeCalloc(TRIES, 1);
90 
91 	if (ptr == 0) {
92 	    returnCode(ERR);
93 	}
94 
95 	SET_TRY(ptr, txt);
96 	ptr->value = 0;
97     }
98 
99     /* at this point, we are adding to the try.  ptr->child == 0 */
100 
101     while (*txt) {
102 	ptr->child = typeCalloc(TRIES, 1);
103 
104 	ptr = ptr->child;
105 
106 	if (ptr == 0) {
107 	    while ((ptr = savedptr) != 0) {
108 		savedptr = ptr->child;
109 		free(ptr);
110 	    }
111 	    returnCode(ERR);
112 	}
113 
114 	SET_TRY(ptr, txt);
115 	ptr->value = 0;
116     }
117 
118     ptr->value = code;
119     returnCode(OK);
120 }
121