minix/external/bsd/flex/dist/ccl.c

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2012-06-06 16:10:32 +02:00
/* $NetBSD: ccl.c,v 1.1.1.1 2009/10/26 00:25:06 christos Exp $ */
/* ccl - routines for character classes */
/* Copyright (c) 1990 The Regents of the University of California. */
/* All rights reserved. */
/* This code is derived from software contributed to Berkeley by */
/* Vern Paxson. */
/* The United States Government has rights in this work pursuant */
/* to contract no. DE-AC03-76SF00098 between the United States */
/* Department of Energy and the University of California. */
/* This file is part of flex. */
/* Redistribution and use in source and binary forms, with or without */
/* modification, are permitted provided that the following conditions */
/* are met: */
/* 1. Redistributions of source code must retain the above copyright */
/* notice, this list of conditions and the following disclaimer. */
/* 2. Redistributions in binary form must reproduce the above copyright */
/* notice, this list of conditions and the following disclaimer in the */
/* documentation and/or other materials provided with the distribution. */
/* Neither the name of the University nor the names of its contributors */
/* may be used to endorse or promote products derived from this software */
/* without specific prior written permission. */
/* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR */
/* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED */
/* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
/* PURPOSE. */
#include "flexdef.h"
/* return true if the chr is in the ccl. Takes negation into account. */
static bool
ccl_contains (const int cclp, const int ch)
{
int ind, len, i;
len = ccllen[cclp];
ind = cclmap[cclp];
for (i = 0; i < len; ++i)
if (ccltbl[ind + i] == ch)
return !cclng[cclp];
return cclng[cclp];
}
/* ccladd - add a single character to a ccl */
void ccladd (cclp, ch)
int cclp;
int ch;
{
int ind, len, newpos, i;
check_char (ch);
len = ccllen[cclp];
ind = cclmap[cclp];
/* check to see if the character is already in the ccl */
for (i = 0; i < len; ++i)
if (ccltbl[ind + i] == ch)
return;
/* mark newlines */
if (ch == nlch)
ccl_has_nl[cclp] = true;
newpos = ind + len;
if (newpos >= current_max_ccl_tbl_size) {
current_max_ccl_tbl_size += MAX_CCL_TBL_SIZE_INCREMENT;
++num_reallocs;
ccltbl = reallocate_Character_array (ccltbl,
current_max_ccl_tbl_size);
}
ccllen[cclp] = len + 1;
ccltbl[newpos] = ch;
}
/* dump_cclp - same thing as list_character_set, but for cclps. */
static void dump_cclp (FILE* file, int cclp)
{
register int i;
putc ('[', file);
for (i = 0; i < csize; ++i) {
if (ccl_contains(cclp, i)){
register int start_char = i;
putc (' ', file);
fputs (readable_form (i), file);
while (++i < csize && ccl_contains(cclp,i)) ;
if (i - 1 > start_char)
/* this was a run */
fprintf (file, "-%s",
readable_form (i - 1));
putc (' ', file);
}
}
putc (']', file);
}
/* ccl_set_diff - create a new ccl as the set difference of the two given ccls. */
int
ccl_set_diff (int a, int b)
{
int d, ch;
/* create new class */
d = cclinit();
/* In order to handle negation, we spin through all possible chars,
* addding each char in a that is not in b.
* (This could be O(n^2), but n is small and bounded.)
*/
for ( ch = 0; ch < csize; ++ch )
if (ccl_contains (a, ch) && !ccl_contains(b, ch))
ccladd (d, ch);
/* debug */
if (0){
fprintf(stderr, "ccl_set_diff (");
fprintf(stderr, "\n ");
dump_cclp (stderr, a);
fprintf(stderr, "\n ");
dump_cclp (stderr, b);
fprintf(stderr, "\n ");
dump_cclp (stderr, d);
fprintf(stderr, "\n)\n");
}
return d;
}
/* ccl_set_union - create a new ccl as the set union of the two given ccls. */
int
ccl_set_union (int a, int b)
{
int d, i;
/* create new class */
d = cclinit();
/* Add all of a */
for (i = 0; i < ccllen[a]; ++i)
ccladd (d, ccltbl[cclmap[a] + i]);
/* Add all of b */
for (i = 0; i < ccllen[b]; ++i)
ccladd (d, ccltbl[cclmap[b] + i]);
/* debug */
if (0){
fprintf(stderr, "ccl_set_union (%d + %d = %d", a, b, d);
fprintf(stderr, "\n ");
dump_cclp (stderr, a);
fprintf(stderr, "\n ");
dump_cclp (stderr, b);
fprintf(stderr, "\n ");
dump_cclp (stderr, d);
fprintf(stderr, "\n)\n");
}
return d;
}
/* cclinit - return an empty ccl */
int cclinit ()
{
if (++lastccl >= current_maxccls) {
current_maxccls += MAX_CCLS_INCREMENT;
++num_reallocs;
cclmap =
reallocate_integer_array (cclmap, current_maxccls);
ccllen =
reallocate_integer_array (ccllen, current_maxccls);
cclng = reallocate_integer_array (cclng, current_maxccls);
ccl_has_nl =
reallocate_bool_array (ccl_has_nl,
current_maxccls);
}
if (lastccl == 1)
/* we're making the first ccl */
cclmap[lastccl] = 0;
else
/* The new pointer is just past the end of the last ccl.
* Since the cclmap points to the \first/ character of a
* ccl, adding the length of the ccl to the cclmap pointer
* will produce a cursor to the first free space.
*/
cclmap[lastccl] =
cclmap[lastccl - 1] + ccllen[lastccl - 1];
ccllen[lastccl] = 0;
cclng[lastccl] = 0; /* ccl's start out life un-negated */
ccl_has_nl[lastccl] = false;
return lastccl;
}
/* cclnegate - negate the given ccl */
void cclnegate (cclp)
int cclp;
{
cclng[cclp] = 1;
ccl_has_nl[cclp] = !ccl_has_nl[cclp];
}
/* list_character_set - list the members of a set of characters in CCL form
*
* Writes to the given file a character-class representation of those
* characters present in the given CCL. A character is present if it
* has a non-zero value in the cset array.
*/
void list_character_set (file, cset)
FILE *file;
int cset[];
{
register int i;
putc ('[', file);
for (i = 0; i < csize; ++i) {
if (cset[i]) {
register int start_char = i;
putc (' ', file);
fputs (readable_form (i), file);
while (++i < csize && cset[i]) ;
if (i - 1 > start_char)
/* this was a run */
fprintf (file, "-%s",
readable_form (i - 1));
putc (' ', file);
}
}
putc (']', file);
}
/** Determines if the range [c1-c2] is unambiguous in a case-insensitive
* scanner. Specifically, if a lowercase or uppercase character, x, is in the
* range [c1-c2], then we require that UPPERCASE(x) and LOWERCASE(x) must also
* be in the range. If not, then this range is ambiguous, and the function
* returns false. For example, [@-_] spans [a-z] but not [A-Z]. Beware that
* [a-z] will be labeled ambiguous because it does not include [A-Z].
*
* @param c1 the lower end of the range
* @param c2 the upper end of the range
* @return true if [c1-c2] is not ambiguous for a caseless scanner.
*/
bool range_covers_case (int c1, int c2)
{
int i, o;
for (i = c1; i <= c2; i++) {
if (has_case (i)) {
o = reverse_case (i);
if (o < c1 || c2 < o)
return false;
}
}
return true;
}
/** Reverse the case of a character, if possible.
* @return c if case-reversal does not apply.
*/
int reverse_case (int c)
{
return isupper (c) ? tolower (c) : (islower (c) ? toupper (c) : c);
}
/** Return true if c is uppercase or lowercase. */
bool has_case (int c)
{
return (isupper (c) || islower (c)) ? true : false;
}