1 /****************************************************************************
2  * Copyright 2019,2020 Thomas E. Dickey                                     *
3  * Copyright 1998-2009,2010 Free Software Foundation, Inc.                  *
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29 
30 /****************************************************************************
31  *  Author: Thomas E. Dickey            1998-on                             *
32  ****************************************************************************/
33 
34 /*
35 **	add_tries.c
36 **
37 **	Add keycode/string to tries-tree.
38 **
39 */
40 
41 #include <curses.priv.h>
42 
43 MODULE_ID("$Id: add_tries.c,v 1.12 2020/02/02 23:34:34 tom Exp $")
44 
45 #define SET_TRY(dst,src) if ((dst->ch = *src++) == 128) dst->ch = '\0'
46 #define CMP_TRY(a,b) ((a)? (a == b) : (b == 128))
47 
48 NCURSES_EXPORT(int)
49 _nc_add_to_try(TRIES ** tree, const char *str, unsigned code)
50 {
51     TRIES *ptr, *savedptr;
52     unsigned const char *txt = (unsigned const char *) str;
53 
54     T((T_CALLED("_nc_add_to_try(%p, %s, %u)"),
55        (void *) *tree, _nc_visbuf(str), code));
56     if (txt == 0 || *txt == '\0' || code == 0)
57 	returnCode(ERR);
58 
59     if ((*tree) != 0) {
60 	ptr = savedptr = (*tree);
61 
62 	for (;;) {
63 	    unsigned char cmp = *txt;
64 
65 	    while (!CMP_TRY(ptr->ch, cmp)
66 		   && ptr->sibling != 0)
67 		ptr = ptr->sibling;
68 
69 	    if (CMP_TRY(ptr->ch, cmp)) {
70 		if (*(++txt) == '\0') {
71 		    ptr->value = (unsigned short) code;
72 		    returnCode(OK);
73 		}
74 		if (ptr->child != 0)
75 		    ptr = ptr->child;
76 		else
77 		    break;
78 	    } else {
79 		if ((ptr->sibling = typeCalloc(TRIES, 1)) == 0) {
80 		    returnCode(ERR);
81 		}
82 
83 		savedptr = ptr = ptr->sibling;
84 		SET_TRY(ptr, txt);
85 		ptr->value = 0;
86 
87 		break;
88 	    }
89 	}			/* end for (;;) */
90     } else {			/* (*tree) == 0 :: First sequence to be added */
91 	savedptr = ptr = (*tree) = typeCalloc(TRIES, 1);
92 
93 	if (ptr == 0) {
94 	    returnCode(ERR);
95 	}
96 
97 	SET_TRY(ptr, txt);
98 	ptr->value = 0;
99     }
100 
101     /* at this point, we are adding to the try.  ptr->child == 0 */
102 
103     while (*txt) {
104 	ptr->child = typeCalloc(TRIES, 1);
105 
106 	ptr = ptr->child;
107 
108 	if (ptr == 0) {
109 	    while ((ptr = savedptr) != 0) {
110 		savedptr = ptr->child;
111 		free(ptr);
112 	    }
113 	    *tree = NULL;
114 	    returnCode(ERR);
115 	}
116 
117 	SET_TRY(ptr, txt);
118 	ptr->value = 0;
119     }
120 
121     ptr->value = (unsigned short) code;
122     returnCode(OK);
123 }
124