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-rw-r--r--libguile/hash.c252
1 files changed, 252 insertions, 0 deletions
diff --git a/libguile/hash.c b/libguile/hash.c
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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"
+}
+