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Diffstat (limited to 'libguile/hash.c')
-rw-r--r-- | libguile/hash.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/libguile/hash.c b/libguile/hash.c new file mode 100644 index 000000000..48f171a61 --- /dev/null +++ b/libguile/hash.c @@ -0,0 +1,252 @@ +/* Copyright (C) 1995,1996 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, 675 Mass Ave, Cambridge, MA 02139, 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" + + + +#ifndef floor +extern double floor(); +#endif + +#ifdef __STDC__ +unsigned long +scm_hasher(SCM obj, unsigned long n, scm_sizet d) +#else +unsigned long +scm_hasher(obj, n, d) + SCM obj; + unsigned long n; + scm_sizet d; +#endif +{ + 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_mb_string: + case scm_tc7_substring: + case scm_tc7_mb_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; + } + } +} + + + + +#ifdef __STDC__ +unsigned int +scm_ihashq (SCM obj, unsigned int n) +#else +unsigned int +scm_ihashq (obj, n) + SCM obj; + unsigned int n; +#endif +{ + return (((unsigned int) obj) >> 1) % n; +} + + +SCM_PROC(s_hashq, "hashq", 2, 0, 0, scm_hashq); +#ifdef __STDC__ +SCM +scm_hashq(SCM obj, SCM n) +#else +SCM +scm_hashq(obj, n) + SCM obj; + SCM n; +#endif +{ + SCM_ASSERT(SCM_INUMP(n) && 0 <= n, n, SCM_ARG2, s_hashq); + return SCM_MAKINUM(scm_ihashq (obj, SCM_INUM (n))); +} + + + + +#ifdef __STDC__ +unsigned int +scm_ihashv (SCM obj, unsigned int n) +#else +unsigned int +scm_ihashv (obj, n) + SCM obj; + unsigned int n; +#endif +{ + 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); +#ifdef __STDC__ +SCM +scm_hashv(SCM obj, SCM n) +#else +SCM +scm_hashv(obj, n) + SCM obj; + SCM n; +#endif +{ + SCM_ASSERT(SCM_INUMP(n) && 0 <= n, n, SCM_ARG2, s_hashv); + return SCM_MAKINUM(scm_ihashv (obj, SCM_INUM (n))); +} + + + + +#ifdef __STDC__ +unsigned int +scm_ihash (SCM obj, unsigned int n) +#else +unsigned int +scm_ihash (obj, n) + SCM obj; + unsigned int n; +#endif +{ + return (unsigned int)scm_hasher (obj, n, 10); +} + +SCM_PROC(s_hash, "hash", 2, 0, 0, scm_hash); +#ifdef __STDC__ +SCM +scm_hash(SCM obj, SCM n) +#else +SCM +scm_hash(obj, n) + SCM obj; + SCM n; +#endif +{ + SCM_ASSERT(SCM_INUMP(n) && 0 <= n, n, SCM_ARG2, s_hash); + return SCM_MAKINUM(scm_ihash(obj, SCM_INUM(n))); +} + + + + +#ifdef __STDC__ +void +scm_init_hash (void) +#else +void +scm_init_hash () +#endif +{ +#include "hash.x" +} + |