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-rw-r--r--doc/ref/api-control.texi7
-rw-r--r--libguile/values.c25
-rw-r--r--libguile/values.h1
-rw-r--r--test-suite/standalone/Makefile.am7
-rw-r--r--test-suite/standalone/test-scm-values.c69
5 files changed, 109 insertions, 0 deletions
diff --git a/doc/ref/api-control.texi b/doc/ref/api-control.texi
index c1502b032..559677874 100644
--- a/doc/ref/api-control.texi
+++ b/doc/ref/api-control.texi
@@ -785,6 +785,13 @@ the current implementation that object shares structure with
@var{args}, so @var{args} should not be modified subsequently.
@end deffn
+@deffn {C Function} scm_c_value_ref (values, idx)
+Returns the value at the position specified by @var{idx} in
+@var{values}. Note that @var{values} will ordinarily be a
+multiple-values object, but it need not be. Any other object
+represents a single value (itself), and is handled appropriately.
+@end deffn
+
@rnindex call-with-values
@deffn {Scheme Procedure} call-with-values producer consumer
Calls its @var{producer} argument with no values and a
diff --git a/libguile/values.c b/libguile/values.c
index ab7773141..9c9e5ff6d 100644
--- a/libguile/values.c
+++ b/libguile/values.c
@@ -67,6 +67,31 @@ print_values (SCM obj, SCM pwps)
return SCM_UNSPECIFIED;
}
+SCM
+scm_c_value_ref (SCM obj, size_t idx)
+{
+ if (SCM_LIKELY (SCM_VALUESP (obj)))
+ {
+ SCM values = scm_struct_ref (obj, SCM_INUM0);
+ size_t i = idx;
+ while (SCM_LIKELY (scm_is_pair (values)))
+ {
+ if (i == 0)
+ return SCM_CAR (values);
+ values = SCM_CDR (values);
+ i--;
+ }
+ }
+ else if (idx == 0)
+ return obj;
+
+ scm_error (scm_out_of_range_key,
+ "scm_c_value_ref",
+ "Too few values in ~S to access index ~S",
+ scm_list_2 (obj, scm_from_unsigned_integer (idx)),
+ scm_list_1 (scm_from_unsigned_integer (idx)));
+}
+
SCM_DEFINE (scm_values, "values", 0, 0, 1,
(SCM args),
"Delivers all of its arguments to its continuation. Except for\n"
diff --git a/libguile/values.h b/libguile/values.h
index 65ad8a119..5f79855be 100644
--- a/libguile/values.h
+++ b/libguile/values.h
@@ -33,6 +33,7 @@ SCM_API SCM scm_values_vtable;
SCM_INTERNAL void scm_i_extract_values_2 (SCM obj, SCM *p1, SCM *p2);
SCM_API SCM scm_values (SCM args);
+SCM_API SCM scm_c_value_ref (SCM values, size_t idx);
SCM_INTERNAL void scm_init_values (void);
#endif /* SCM_VALUES_H */
diff --git a/test-suite/standalone/Makefile.am b/test-suite/standalone/Makefile.am
index 08d249c48..d8cfafa25 100644
--- a/test-suite/standalone/Makefile.am
+++ b/test-suite/standalone/Makefile.am
@@ -189,6 +189,13 @@ test_scm_to_latin1_string_LDADD = $(LIBGUILE_LDADD)
check_PROGRAMS += test-scm-to-latin1-string
TESTS += test-scm-to-latin1-string
+# test-scm-values
+test_scm_values_SOURCES = test-scm-values.c
+test_scm_values_CFLAGS = ${test_cflags}
+test_scm_values_LDADD = $(LIBGUILE_LDADD)
+check_PROGRAMS += test-scm-values
+TESTS += test-scm-values
+
if HAVE_SHARED_LIBRARIES
# test-extensions
diff --git a/test-suite/standalone/test-scm-values.c b/test-suite/standalone/test-scm-values.c
new file mode 100644
index 000000000..ece62dab6
--- /dev/null
+++ b/test-suite/standalone/test-scm-values.c
@@ -0,0 +1,69 @@
+/* Copyright (C) 2012 Free Software Foundation, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <assert.h>
+#include <libguile.h>
+#include <stdlib.h>
+#include <string.h>
+
+static void
+test_scm_c_value_ref_on_multiple_values ()
+{
+ SCM values = scm_values (scm_list_3 (scm_from_latin1_string ("foo"),
+ scm_from_latin1_string ("bar"),
+ scm_from_latin1_string ("baz")));
+
+ char *foo = scm_to_latin1_string (scm_c_value_ref (values, 0));
+ char *bar = scm_to_latin1_string (scm_c_value_ref (values, 1));
+ char *baz = scm_to_latin1_string (scm_c_value_ref (values, 2));
+
+ assert (strcmp (foo, "foo") == 0);
+ assert (strcmp (bar, "bar") == 0);
+ assert (strcmp (baz, "baz") == 0);
+
+ free (foo);
+ free (bar);
+ free (baz);
+}
+
+static void
+test_scm_c_value_ref_on_a_single_value ()
+{
+ SCM value = scm_from_latin1_string ("foo");
+ char *foo = scm_to_latin1_string (scm_c_value_ref (value, 0));
+ assert (strcmp (foo, "foo") == 0);
+ free (foo);
+}
+
+static void
+tests (void *data, int argc, char **argv)
+{
+ test_scm_c_value_ref_on_multiple_values ();
+ test_scm_c_value_ref_on_a_single_value ();
+}
+
+int
+main (int argc, char *argv[])
+{
+ scm_boot_guile (argc, argv, tests, NULL);
+ return 0;
+}