1 /* ecs - equivalence class routines */
3 /* Copyright (c) 1990 The Regents of the University of California. */
4 /* All rights reserved. */
6 /* This code is derived from software contributed to Berkeley by */
9 /* The United States Government has rights in this work pursuant */
10 /* to contract no. DE-AC03-76SF00098 between the United States */
11 /* Department of Energy and the University of California. */
13 /* This file is part of flex */
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16 /* modification, are permitted provided that the following conditions */
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25 /* Neither the name of the University nor the names of its contributors */
26 /* may be used to endorse or promote products derived from this software */
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29 /* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR */
30 /* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED */
31 /* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
37 /* ccl2ecl - convert character classes to set of equivalence classes */
41 int i, ich, newlen, cclp, ccls, cclmec;
43 for (i = 1; i <= lastccl; ++i) {
44 /* We loop through each character class, and for each character
45 * in the class, add the character's equivalence class to the
46 * new "character" class we are creating. Thus when we are all
47 * done, character classes will really consist of collections
48 * of equivalence classes
54 for (ccls = 0; ccls < ccllen[i]; ++ccls) {
55 ich = ccltbl[cclp + ccls];
56 cclmec = ecgroup[ich];
59 /* Note: range 1..256 is mapped to 1..255,0 */
60 ccltbl[cclp + newlen] = (unsigned char) cclmec;
70 /* cre8ecs - associate equivalence class numbers with class members
72 * fwd is the forward linked-list of equivalence class members. bck
73 * is the backward linked-list, and num is the number of class members.
75 * Returned is the number of classes.
78 int cre8ecs (int fwd[], int bck[], int num)
84 /* Create equivalence class numbers. From now on, ABS( bck(x) )
85 * is the equivalence class number for object x. If bck(x)
86 * is positive, then x is the representative of its equivalence
89 for (i = 1; i <= num; ++i)
92 for (j = fwd[i]; j != NIL; j = fwd[j])
100 /* mkeccl - update equivalence classes based on character class xtions
103 * unsigned char ccls[];
104 * int lenccl, fwd[llsiz], bck[llsiz], llsiz, NUL_mapping;
105 * void mkeccl( unsigned char ccls[], int lenccl, int fwd[llsiz], int bck[llsiz],
106 * int llsiz, int NUL_mapping );
108 * ccls contains the elements of the character class, lenccl is the
109 * number of elements in the ccl, fwd is the forward link-list of equivalent
110 * characters, bck is the backward link-list, and llsiz size of the link-list.
112 * NUL_mapping is the value which NUL (0) should be mapped to.
115 void mkeccl (unsigned char ccls[], int lenccl, int fwd[], int bck[], int llsiz, int NUL_mapping)
117 int cclp, oldec, newec;
119 static unsigned char cclflags[CSIZE]; /* initialized to all '\0' */
121 /* Note that it doesn't matter whether or not the character class is
122 * negated. The same results will be obtained in either case.
127 while (cclp < lenccl) {
130 if (NUL_mapping && cclm == 0)
138 for (i = fwd[cclm]; i != NIL && i <= llsiz; i = fwd[i]) { /* look for the symbol in the character class */
139 for (; j < lenccl; ++j) {
142 if (NUL_mapping && ccls[j] == 0)
143 ccl_char = NUL_mapping;
150 if (ccl_char == i && !cclflags[j]) {
151 /* We found an old companion of cclm
152 * in the ccl. Link it into the new
153 * equivalence class and flag it as
154 * having been processed.
160 /* Set flag so we don't reprocess. */
163 /* Get next equivalence class member. */
169 /* Symbol isn't in character class. Put it in the old
183 if (bck[cclm] != NIL || oldec != bck[cclm]) {
190 /* Find next ccl member to process. */
192 for (++cclp; cclp < lenccl && cclflags[cclp]; ++cclp) {
193 /* Reset "doesn't need processing" flag. */
200 /* mkechar - create equivalence class for single character */
202 void mkechar (int tch, int fwd[], int bck[])
204 /* If until now the character has been a proper subset of
205 * an equivalence class, break it away to create a new ec
209 bck[fwd[tch]] = bck[tch];
212 fwd[bck[tch]] = fwd[tch];