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1 | /* Copyright (C) 1995, 1996 Tom Lord | |
2 | * | |
3 | * This program is free software; you can redistribute it and/or modify | |
4 | * it under the terms of the GNU Library General Public License as published by | |
5 | * the Free Software Foundation; either version 2, or (at your option) | |
6 | * any later version. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU Library General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU Library General Public License | |
14 | * along with this software; see the file COPYING. If not, write to | |
15 | * the Free Software Foundation, 59 Temple Place - Suite 330, | |
16 | * Boston, MA 02111-1307, USA. | |
17 | */ | |
18 | ||
19 | \f | |
20 | ||
21 | #include "rxall.h" | |
22 | #include "rxsimp.h" | |
23 | ||
24 | \f | |
25 | ||
26 | ||
27 | /* Could reasonably hashcons instead of in rxunfa.c */ | |
28 | ||
29 | #ifdef __STDC__ | |
30 | int | |
31 | rx_simple_rexp (struct rexp_node ** answer, | |
32 | int cset_size, | |
33 | struct rexp_node *node, | |
34 | struct rexp_node ** subexps) | |
35 | #else | |
36 | int | |
37 | rx_simple_rexp (answer, cset_size, node, subexps) | |
38 | struct rexp_node ** answer; | |
39 | int cset_size; | |
40 | struct rexp_node *node; | |
41 | struct rexp_node ** subexps; | |
42 | #endif | |
43 | { | |
44 | int stat; | |
45 | ||
46 | if (!node) | |
47 | { | |
48 | *answer = 0; | |
49 | return 0; | |
50 | } | |
51 | ||
52 | if (!node->observed) | |
53 | { | |
54 | rx_save_rexp (node); | |
55 | *answer = node; | |
56 | return 0; | |
57 | } | |
58 | ||
59 | if (node->simplified) | |
60 | { | |
61 | rx_save_rexp (node->simplified); | |
62 | *answer = node->simplified; | |
63 | return 0; | |
64 | } | |
65 | ||
66 | switch (node->type) | |
67 | { | |
68 | default: | |
69 | case r_cset: | |
70 | case r_string: | |
71 | case r_cut: | |
72 | return -2; /* an internal error, really */ | |
73 | ||
74 | case r_parens: | |
75 | stat = rx_simple_rexp (answer, cset_size, | |
76 | node->params.pair.left, | |
77 | subexps); | |
78 | break; | |
79 | ||
80 | case r_context: | |
81 | if (isdigit (node->params.intval)) | |
82 | stat = rx_simple_rexp (answer, cset_size, | |
83 | subexps [node->params.intval - '0'], | |
84 | subexps); | |
85 | else | |
86 | { | |
87 | *answer = 0; | |
88 | stat = 0; | |
89 | } | |
90 | break; | |
91 | ||
92 | case r_concat: | |
93 | case r_alternate: | |
94 | case r_opt: | |
95 | case r_star: | |
96 | case r_plus: | |
97 | case r_interval: | |
98 | { | |
99 | struct rexp_node *n; | |
100 | n = rexp_node (node->type); | |
101 | if (!n) | |
102 | return -1; | |
103 | ||
104 | if (node->params.cset) | |
105 | { | |
106 | n->params.cset = rx_copy_cset (cset_size, | |
107 | node->params.cset); | |
108 | if (!n->params.cset) | |
109 | { | |
110 | rx_free_rexp (n); | |
111 | return -1; | |
112 | } | |
113 | } | |
114 | n->params.intval = node->params.intval; | |
115 | n->params.intval2 = node->params.intval2; | |
116 | { | |
117 | int s; | |
118 | ||
119 | s = rx_simple_rexp (&n->params.pair.left, cset_size, | |
120 | node->params.pair.left, subexps); | |
121 | if (!s) | |
122 | s = rx_simple_rexp (&n->params.pair.right, cset_size, | |
123 | node->params.pair.right, subexps); | |
124 | if (!s) | |
125 | { | |
126 | *answer = n; | |
127 | stat = 0; | |
128 | } | |
129 | else | |
130 | { | |
131 | rx_free_rexp (n); | |
132 | stat = s; | |
133 | } | |
134 | } | |
135 | } | |
136 | break; | |
137 | } | |
138 | ||
139 | if (!stat) | |
140 | { | |
141 | node->simplified = *answer; | |
142 | rx_save_rexp (node->simplified); | |
143 | } | |
144 | return stat; | |
145 | } | |
146 | ||
147 |