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/* Copyright (C) 1995,1996, 1997 Free Software Foundation, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*
* As a special exception, the Free Software Foundation gives permission
* for additional uses of the text contained in its release of GUILE.
*
* The exception is that, if you link the GUILE library with other files
* to produce an executable, this does not by itself cause the
* resulting executable to be covered by the GNU General Public License.
* Your use of that executable is in no way restricted on account of
* linking the GUILE library code into it.
*
* This exception does not however invalidate any other reasons why
* the executable file might be covered by the GNU General Public License.
*
* This exception applies only to the code released by the
* Free Software Foundation under the name GUILE. If you copy
* code from other Free Software Foundation releases into a copy of
* GUILE, as the General Public License permits, the exception does
* not apply to the code that you add in this way. To avoid misleading
* anyone as to the status of such modified files, you must delete
* this exception notice from them.
*
* If you write modifications of your own for GUILE, it is your choice
* whether to permit this exception to apply to your modifications.
* If you do not wish that, delete this exception notice. */
#include <stdio.h>
#include "_scm.h"
#include "chars.h"
#include "hash.h"
#ifndef floor
extern double floor();
#endif
unsigned long
scm_hasher(obj, n, d)
SCM obj;
unsigned long n;
scm_sizet d;
{
switch (7 & (int) obj) {
case 2: case 6: /* SCM_INUMP(obj) */
return SCM_INUM(obj) % n;
case 4:
if SCM_ICHRP(obj)
return (unsigned)(scm_downcase(SCM_ICHR(obj))) % n;
switch ((int) obj) {
#ifndef SICP
case (int) SCM_EOL: d = 256; break;
#endif
case (int) SCM_BOOL_T: d = 257; break;
case (int) SCM_BOOL_F: d = 258; break;
case (int) SCM_EOF_VAL: d = 259; break;
default: d = 263; /* perhaps should be error */
}
return d % n;
default: return 263 % n; /* perhaps should be error */
case 0:
switch SCM_TYP7(obj) {
default: return 263 % n;
case scm_tc7_smob:
switch SCM_TYP16(obj) {
case scm_tcs_bignums:
bighash: return SCM_INUM(scm_modulo(obj, SCM_MAKINUM(n)));
default: return 263 % n;
#ifdef SCM_FLOATS
case scm_tc16_flo:
if SCM_REALP(obj) {
double r = SCM_REALPART(obj);
if (floor(r)==r) {
obj = scm_inexact_to_exact (obj);
if SCM_IMP(obj) return SCM_INUM(obj) % n;
goto bighash;
}
}
obj = scm_number_to_string(obj, SCM_MAKINUM(10));
#endif
}
case scm_tcs_symbols:
case scm_tc7_string:
case scm_tc7_substring:
return scm_strhash(SCM_ROUCHARS(obj), (scm_sizet) SCM_ROLENGTH(obj), n);
case scm_tc7_wvect:
case scm_tc7_vector:
{
scm_sizet len = SCM_LENGTH(obj);
SCM *data = SCM_VELTS(obj);
if (len>5)
{
scm_sizet i = d/2;
unsigned long h = 1;
while (i--) h = ((h<<8) + (scm_hasher(data[h % len], n, 2))) % n;
return h;
}
else
{
scm_sizet i = len;
unsigned long h = (n)-1;
while (i--) h = ((h<<8) + (scm_hasher(data[i], n, d/len))) % n;
return h;
}
}
case scm_tcs_cons_imcar: case scm_tcs_cons_nimcar:
if (d) return (scm_hasher(SCM_CAR(obj), n, d/2)+scm_hasher(SCM_CDR(obj), n, d/2)) % n;
else return 1;
case scm_tc7_port:
return ((SCM_RDNG & SCM_CAR(obj)) ? 260 : 261) % n;
case scm_tcs_closures: case scm_tc7_contin: case scm_tcs_subrs:
return 262 % n;
}
}
}
unsigned int
scm_ihashq (obj, n)
SCM obj;
unsigned int n;
{
return (((unsigned int) obj) >> 1) % n;
}
SCM_PROC(s_hashq, "hashq", 2, 0, 0, scm_hashq);
SCM
scm_hashq(obj, n)
SCM obj;
SCM n;
{
SCM_ASSERT(SCM_INUMP(n) && 0 <= n, n, SCM_ARG2, s_hashq);
return SCM_MAKINUM(scm_ihashq (obj, SCM_INUM (n)));
}
unsigned int
scm_ihashv (obj, n)
SCM obj;
unsigned int n;
{
if (SCM_ICHRP(obj))
return ((unsigned int)(scm_downcase(SCM_ICHR(obj)))) % n; /* downcase!?!! */
if (SCM_NIMP(obj) && SCM_NUMP(obj))
return (unsigned int) scm_hasher(obj, n, 10);
else
return ((unsigned int)obj) % n;
}
SCM_PROC(s_hashv, "hashv", 2, 0, 0, scm_hashv);
SCM
scm_hashv(obj, n)
SCM obj;
SCM n;
{
SCM_ASSERT(SCM_INUMP(n) && 0 <= n, n, SCM_ARG2, s_hashv);
return SCM_MAKINUM(scm_ihashv (obj, SCM_INUM (n)));
}
unsigned int
scm_ihash (obj, n)
SCM obj;
unsigned int n;
{
return (unsigned int)scm_hasher (obj, n, 10);
}
SCM_PROC(s_hash, "hash", 2, 0, 0, scm_hash);
SCM
scm_hash(obj, n)
SCM obj;
SCM n;
{
SCM_ASSERT(SCM_INUMP(n) && 0 <= n, n, SCM_ARG2, s_hash);
return SCM_MAKINUM(scm_ihash(obj, SCM_INUM(n)));
}
void
scm_init_hash ()
{
#include "hash.x"
}
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