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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 1.10 2010/12/19 01:31:14 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)"),
54        (void *) *tree, _nc_visbuf(str), code));
55     if (txt == 0 || *txt == '\0' || code == 0)
56 	returnCode(ERR);
57 
58     if ((*tree) != 0) {
59 	ptr = savedptr = (*tree);
60 
61 	for (;;) {
62 	    unsigned char cmp = *txt;
63 
64 	    while (!CMP_TRY(ptr->ch, cmp)
65 		   && ptr->sibling != 0)
66 		ptr = ptr->sibling;
67 
68 	    if (CMP_TRY(ptr->ch, cmp)) {
69 		if (*(++txt) == '\0') {
70 		    ptr->value = (unsigned short) code;
71 		    returnCode(OK);
72 		}
73 		if (ptr->child != 0)
74 		    ptr = ptr->child;
75 		else
76 		    break;
77 	    } else {
78 		if ((ptr->sibling = typeCalloc(TRIES, 1)) == 0) {
79 		    returnCode(ERR);
80 		}
81 
82 		savedptr = ptr = ptr->sibling;
83 		SET_TRY(ptr, txt);
84 		ptr->value = 0;
85 
86 		break;
87 	    }
88 	}			/* end for (;;) */
89     } else {			/* (*tree) == 0 :: First sequence to be added */
90 	savedptr = ptr = (*tree) = typeCalloc(TRIES, 1);
91 
92 	if (ptr == 0) {
93 	    returnCode(ERR);
94 	}
95 
96 	SET_TRY(ptr, txt);
97 	ptr->value = 0;
98     }
99 
100     /* at this point, we are adding to the try.  ptr->child == 0 */
101 
102     while (*txt) {
103 	ptr->child = typeCalloc(TRIES, 1);
104 
105 	ptr = ptr->child;
106 
107 	if (ptr == 0) {
108 	    while ((ptr = savedptr) != 0) {
109 		savedptr = ptr->child;
110 		free(ptr);
111 	    }
112 	    returnCode(ERR);
113 	}
114 
115 	SET_TRY(ptr, txt);
116 	ptr->value = 0;
117     }
118 
119     ptr->value = (unsigned short) code;
120     returnCode(OK);
121 }
122