Finish converting struct variable to an opaque type. In this

[pspp-builds.git] / src / data / value.c

diff --git a/src/data/value.c b/src/data/value.c
new file mode 100644 (file)
index 0000000..2de3adb
--- /dev/null
+++ b/src/data/value.c
@@ -0,0 +1,56 @@
+/* PSPP - computes sample statistics.
+   Copyright (C) 1997-9, 2000 Free Software Foundation, Inc.
+   Written by Ben Pfaff <blp@gnu.org>.
+
+   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 of the
+   License, 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 program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301, USA. */
+
+#include <config.h>
+#include "value.h"
+
+#include <libpspp/hash.h>
+#include <libpspp/str.h>
+
+#include "xalloc.h"
+
+/* Duplicate a value.
+   The caller is responsible for freeing the returned value. */
+union value *
+value_dup (const union value *val, int width)
+{
+  return xmemdup (val, MAX (width, sizeof *val));
+}
+
+/* Compares A and B, which both have the given WIDTH, and returns
+   a strcmp()-type result.
+   Only the short string portion of longer strings are
+   compared. */
+int
+compare_values (const union value *a, const union value *b, int width) 
+{
+  return (width == 0
+          ? (a->f < b->f ? -1 : a->f > b->f)
+          : memcmp (a->s, b->s, MIN (MAX_SHORT_STRING, width)));
+}
+
+/* Create a hash of V, which has the given WIDTH.
+   Only the short string portion of a longer string is hashed. */
+unsigned 
+hash_value (const union value *v, int width)
+{
+  return (width == 0
+          ? hsh_hash_double (v->f)
+          : hsh_hash_bytes (v->s, MIN (MAX_SHORT_STRING, width)));
+}