mongodb/pcre-7.4/pcre_ucp_searchfuncs.c

/*************************************************
*      Perl-Compatible Regular Expressions       *
*************************************************/

/* PCRE is a library of functions to support regular expressions whose syntax
and semantics are as close as possible to those of the Perl 5 language.

                       Written by Philip Hazel
           Copyright (c) 1997-2007 University of Cambridge

-----------------------------------------------------------------------------
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.

    * 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 of Cambridge 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 BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
-----------------------------------------------------------------------------
*/


/* This module contains code for searching the table of Unicode character
properties. */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "pcre_internal.h"

#include "ucp.h"               /* Category definitions */
#include "ucpinternal.h"       /* Internal table details */
#include "ucptable.h"          /* The table itself */


/* Table to translate from particular type value to the general value. */

static const int ucp_gentype[] = {
  ucp_C, ucp_C, ucp_C, ucp_C, ucp_C,  /* Cc, Cf, Cn, Co, Cs */
  ucp_L, ucp_L, ucp_L, ucp_L, ucp_L,  /* Ll, Lu, Lm, Lo, Lt */
  ucp_M, ucp_M, ucp_M,                /* Mc, Me, Mn */
  ucp_N, ucp_N, ucp_N,                /* Nd, Nl, No */
  ucp_P, ucp_P, ucp_P, ucp_P, ucp_P,  /* Pc, Pd, Pe, Pf, Pi */
  ucp_P, ucp_P,                       /* Ps, Po */
  ucp_S, ucp_S, ucp_S, ucp_S,         /* Sc, Sk, Sm, So */
  ucp_Z, ucp_Z, ucp_Z                 /* Zl, Zp, Zs */
};



/*************************************************
*         Search table and return type           *
*************************************************/

/* Three values are returned: the category is ucp_C, ucp_L, etc. The detailed
character type is ucp_Lu, ucp_Nd, etc. The script is ucp_Latin, etc.

Arguments:
  c           the character value
  type_ptr    the detailed character type is returned here
  script_ptr  the script is returned here

Returns:      the character type category
*/

int
_pcre_ucp_findprop(const unsigned int c, int *type_ptr, int *script_ptr)
{
int bot = 0;
int top = sizeof(ucp_table)/sizeof(cnode);
int mid;

/* The table is searched using a binary chop. You might think that using
intermediate variables to hold some of the common expressions would speed
things up, but tests with gcc 3.4.4 on Linux showed that, on the contrary, it
makes things a lot slower. */

for (;;)
  {
  if (top <= bot)
    {
    *type_ptr = ucp_Cn;
    *script_ptr = ucp_Common;
    return ucp_C;
    }
  mid = (bot + top) >> 1;
  if (c == (ucp_table[mid].f0 & f0_charmask)) break;
  if (c < (ucp_table[mid].f0 & f0_charmask)) top = mid;
  else
    {
    if ((ucp_table[mid].f0 & f0_rangeflag) != 0 &&
        c <= (ucp_table[mid].f0 & f0_charmask) +
             (ucp_table[mid].f1 & f1_rangemask)) break;
    bot = mid + 1;
    }
  }

/* Found an entry in the table. Set the script and detailed type values, and
return the general type. */

*script_ptr = (ucp_table[mid].f0 & f0_scriptmask) >> f0_scriptshift;
*type_ptr = (ucp_table[mid].f1 & f1_typemask) >> f1_typeshift;

return ucp_gentype[*type_ptr];
}



/*************************************************
*       Search table and return other case       *
*************************************************/

/* If the given character is a letter, and there is another case for the
letter, return the other case. Otherwise, return -1.

Arguments:
  c           the character value

Returns:      the other case or NOTACHAR if none
*/

unsigned int
_pcre_ucp_othercase(const unsigned int c)
{
int bot = 0;
int top = sizeof(ucp_table)/sizeof(cnode);
int mid, offset;

/* The table is searched using a binary chop. You might think that using
intermediate variables to hold some of the common expressions would speed
things up, but tests with gcc 3.4.4 on Linux showed that, on the contrary, it
makes things a lot slower. */

for (;;)
  {
  if (top <= bot) return -1;
  mid = (bot + top) >> 1;
  if (c == (ucp_table[mid].f0 & f0_charmask)) break;
  if (c < (ucp_table[mid].f0 & f0_charmask)) top = mid;
  else
    {
    if ((ucp_table[mid].f0 & f0_rangeflag) != 0 &&
        c <= (ucp_table[mid].f0 & f0_charmask) +
             (ucp_table[mid].f1 & f1_rangemask)) break;
    bot = mid + 1;
    }
  }

/* Found an entry in the table. Return NOTACHAR for a range entry. Otherwise
return the other case if there is one, else NOTACHAR. */

if ((ucp_table[mid].f0 & f0_rangeflag) != 0) return NOTACHAR;

offset = ucp_table[mid].f1 & f1_casemask;
if ((offset & f1_caseneg) != 0) offset |= f1_caseneg;
return (offset == 0)? NOTACHAR : c + offset;
}


/* End of pcre_ucp_searchfuncs.c */