source: trunk/essentials/sys-devel/flex/ccl.c@ 3706

/* 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"

/* 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;
}


/* 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;
}