1/*	$NetBSD: parse.c,v 1.18 2021/05/02 12:50:43 rillig Exp $	*/
2
3/*
4 * Copyright (c) 1983, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#ifndef lint
34#if 0
35static char sccsid[] = "@(#)parse.c	8.2 (Berkeley) 4/28/95";
36#else
37__RCSID("$NetBSD: parse.c,v 1.18 2021/05/02 12:50:43 rillig Exp $");
38#endif
39#endif				/* not lint */
40
41#include "extern.h"
42
43#define HASHSIZE	256
44#define HASHMUL		81
45#define HASHMASK	(HASHSIZE - 1)
46
47static int hash(const char *);
48static void install(struct wlist *);
49static struct wlist *lookup(const char *);
50
51static struct wlist *hashtab[HASHSIZE];
52
53void
54wordinit(void)
55{
56	struct wlist *w;
57
58	for (w = wlist; w->string; w++)
59		install(w);
60}
61
62static int
63hash(const char *s)
64{
65	int     hashval = 0;
66
67	while (*s) {
68		hashval += *s++;
69		hashval *= HASHMUL;
70		hashval &= HASHMASK;
71	}
72	return hashval;
73}
74
75static struct wlist *
76lookup(const char   *s)
77{
78	struct wlist *wp;
79
80	for (wp = hashtab[hash(s)]; wp != NULL; wp = wp->next)
81		if (*s == *wp->string && strcmp(s, wp->string) == 0)
82			return wp;
83	return NULL;
84}
85
86static void
87install(struct wlist *wp)
88{
89	int     hashval;
90
91	if (lookup(wp->string) == NULL) {
92		hashval = hash(wp->string);
93		wp->next = hashtab[hashval];
94		hashtab[hashval] = wp;
95	} else
96		printf("Multiply defined %s.\n", wp->string);
97}
98
99void
100parse(void)
101{
102	struct wlist *wp;
103	int     n;
104	int     flag;
105
106	wordnumber = 0;		/* for cypher */
107	for (n = 0; n <= wordcount; n++) {
108		if ((wp = lookup(words[n])) == NULL) {
109			wordvalue[n] = -1;
110			wordtype[n] = -1;
111		} else {
112			wordvalue[n] = wp->value;
113			wordtype[n] = wp->article;
114		}
115	}
116	/* We never use adjectives for anything, so yank them all. */
117	for (n = 1; n < wordcount; n++)
118		if (wordtype[n] == ADJS) {
119			int i;
120			for (i = n + 1; i < wordcount; i++) {
121				wordtype[i - 1] = wordtype[i];
122				wordvalue[i - 1] = wordvalue[i];
123				strlcpy(words[i - 1], words[i], WORDLEN);
124			}
125			wordcount--;
126		}
127	/* Don't let a comma mean AND if followed by a verb. */
128	for (n = 0; n < wordcount; n++)
129		if (wordvalue[n] == AND && words[n][0] == ','
130		    && wordtype[n + 1] == VERB) {
131			wordvalue[n] = -1;
132			wordtype[n] = -1;
133		}
134	/* Trim "AND AND" which can happen naturally at the end of a
135	 * comma-delimited list.
136	 */
137	for (n = 1; n < wordcount; n++)
138		if (wordvalue[n - 1] == AND && wordvalue[n] == AND) {
139			int i;
140			for (i = n + 1; i < wordcount; i++) {
141				wordtype[i - 1] = wordtype[i];
142				wordvalue[i - 1] = wordvalue[i];
143				strlcpy(words[i - 1], words[i], WORDLEN);
144			}
145			wordcount--;
146		}
147
148	/* If there is a sequence (NOUN | OBJECT) AND EVERYTHING
149	 * then move all the EVERYTHINGs to the beginning, since that's where
150	 * they're expected.  We can't get rid of the NOUNs and OBJECTs in
151	 * case they aren't in EVERYTHING (i.e. not here or nonexistent).
152	 */
153	flag = 1;
154	while (flag) {
155		flag = 0;
156		for (n = 1; n < wordcount; n++)
157			if ((wordtype[n - 1] == NOUNS ||
158			    wordtype[n - 1] == OBJECT) &&
159			    wordvalue[n] == AND &&
160			    wordvalue[n + 1] == EVERYTHING) {
161				char tmpword[WORDLEN];
162				wordvalue[n + 1] = wordvalue[n - 1];
163				wordvalue[n - 1] = EVERYTHING;
164				wordtype[n + 1] = wordtype[n - 1];
165				wordtype[n - 1] = OBJECT;
166				strcpy(tmpword, words[n - 1]);
167				strlcpy(words[n - 1], words[n + 1], WORDLEN);
168				strcpy(words[n + 1], tmpword);
169				flag = 1;
170		}
171		/* And trim EVERYTHING AND EVERYTHING. */
172		for (n = 1; n < wordcount; n++)
173			if (wordvalue[n - 1] == EVERYTHING &&
174			    wordvalue[n] == AND &&
175			    wordvalue[n + 1] == EVERYTHING) {
176				int i;
177				for (i = n + 1; i < wordcount; i++) {
178					wordtype[i - 1] = wordtype[i + 1];
179					wordvalue[i - 1] = wordvalue[i + 1];
180					strlcpy(words[i - 1], words[i + 1], WORDLEN);
181				}
182				wordcount--;
183				wordcount--;
184				flag = 1;
185			}
186	}
187}
188