add_tries.c revision 62449 
1/****************************************************************************
2 * Copyright (c) 1998,2000 Free Software Foundation, Inc.                   *
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28
29/****************************************************************************
30 *  Author: Thomas E. Dickey <dickey@clark.net> 1998                        *
31 ****************************************************************************/
32
33/*
34**	add_tries.c
35**
36**	Add keycode/string to tries-tree.
37**
38*/
39
40#include <curses.priv.h>
41
42MODULE_ID("$Id: add_tries.c,v 1.2 2000/03/18 22:23:56 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
47void
48_nc_add_to_try(struct tries **tree, const char *str, unsigned short code)
49{
50    static bool out_of_memory = FALSE;
51    struct tries *ptr, *savedptr;
52    unsigned const char *txt = (unsigned const char *) str;
53
54    if (txt == 0 || *txt == '\0' || out_of_memory || code == 0)
55	return;
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		    return;
71		}
72		if (ptr->child != 0)
73		    ptr = ptr->child;
74		else
75		    break;
76	    } else {
77		if ((ptr->sibling = typeCalloc(struct tries, 1)) == 0) {
78		    out_of_memory = TRUE;
79		    return;
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(struct tries, 1);
91
92	if (ptr == 0) {
93	    out_of_memory = TRUE;
94	    return;
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(struct tries, 1);
105
106	ptr = ptr->child;
107
108	if (ptr == 0) {
109	    out_of_memory = TRUE;
110
111	    while ((ptr = savedptr) != 0) {
112		savedptr = ptr->child;
113		free(ptr);
114	    }
115
116	    return;
117	}
118
119	SET_TRY(ptr, txt);
120	ptr->value = 0;
121    }
122
123    ptr->value = code;
124    return;
125}
126