--- /dev/null
+/* Copyright (C) 1995,1996,2000,2001, 2004, 2005, 2006, 2008 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 2.1 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
+ */
+
+
+\f
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "libguile/_scm.h"
+#include "libguile/validate.h"
+
+#include "libguile/pairs.h"
+
+\f
+
+/* {Pairs}
+ */
+
+#if (SCM_DEBUG_PAIR_ACCESSES == 1)
+
+#include "libguile/ports.h"
+#include "libguile/strings.h"
+
+void scm_error_pair_access (SCM non_pair)
+{
+ static unsigned int running = 0;
+ SCM message = scm_from_locale_string ("Non-pair accessed with SCM_C[AD]R: `~S'\n");
+
+ if (!running)
+ {
+ running = 1;
+ scm_simple_format (scm_current_error_port (),
+ message, scm_list_1 (non_pair));
+ abort ();
+ }
+}
+
+#endif
+
+SCM_DEFINE (scm_cons, "cons", 2, 0, 0,
+ (SCM x, SCM y),
+ "Return a newly allocated pair whose car is @var{x} and whose\n"
+ "cdr is @var{y}. The pair is guaranteed to be different (in the\n"
+ "sense of @code{eq?}) from every previously existing object.")
+#define FUNC_NAME s_scm_cons
+{
+ return scm_cell (SCM_UNPACK (x), SCM_UNPACK (y));
+}
+#undef FUNC_NAME
+
+
+SCM
+scm_cons2 (SCM w, SCM x, SCM y)
+{
+ return scm_cons (w, scm_cons (x, y));
+}
+
+
+SCM_DEFINE (scm_pair_p, "pair?", 1, 0, 0,
+ (SCM x),
+ "Return @code{#t} if @var{x} is a pair; otherwise return\n"
+ "@code{#f}.")
+#define FUNC_NAME s_scm_pair_p
+{
+ return scm_from_bool (scm_is_pair (x));
+}
+#undef FUNC_NAME
+
+SCM
+scm_car (SCM pair)
+{
+ if (!scm_is_pair (pair))
+ scm_wrong_type_arg_msg (NULL, 0, pair, "pair");
+ return SCM_CAR (pair);
+}
+
+SCM
+scm_cdr (SCM pair)
+{
+ if (!scm_is_pair (pair))
+ scm_wrong_type_arg_msg (NULL, 0, pair, "pair");
+ return SCM_CDR (pair);
+}
+
+SCM
+scm_i_chase_pairs (SCM tree, scm_t_uint32 pattern)
+{
+ do
+ {
+ if (!scm_is_pair (tree))
+ scm_wrong_type_arg_msg (NULL, 0, tree, "pair");
+ tree = (pattern & 1) ? SCM_CAR (tree) : SCM_CDR (tree);
+ pattern >>= 2;
+ }
+ while (pattern);
+ return tree;
+}
+
+SCM_DEFINE (scm_set_car_x, "set-car!", 2, 0, 0,
+ (SCM pair, SCM value),
+ "Stores @var{value} in the car field of @var{pair}. The value returned\n"
+ "by @code{set-car!} is unspecified.")
+#define FUNC_NAME s_scm_set_car_x
+{
+ SCM_VALIDATE_CONS (1, pair);
+ SCM_SETCAR (pair, value);
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_set_cdr_x, "set-cdr!", 2, 0, 0,
+ (SCM pair, SCM value),
+ "Stores @var{value} in the cdr field of @var{pair}. The value returned\n"
+ "by @code{set-cdr!} is unspecified.")
+#define FUNC_NAME s_scm_set_cdr_x
+{
+ SCM_VALIDATE_CONS (1, pair);
+ SCM_SETCDR (pair, value);
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+\f
+
+/* Every cxr-pattern is made up of pairs of bits, starting with the two least
+ * significant bits. If in a pair of bits the least significant of the two
+ * bits is 0, this means CDR, otherwise CAR. The most significant bits of the
+ * two bits is only needed to indicate when cxr-ing is ready. This is the
+ * case, when all remaining pairs of bits equal 00. */
+
+typedef struct {
+ const char *name;
+ unsigned char pattern;
+} t_cxr;
+
+static const t_cxr cxrs[] =
+{
+ {"cdr", 0x02}, /* 00000010 */
+ {"car", 0x03}, /* 00000011 */
+ {"cddr", 0x0a}, /* 00001010 */
+ {"cdar", 0x0b}, /* 00001011 */
+ {"cadr", 0x0e}, /* 00001110 */
+ {"caar", 0x0f}, /* 00001111 */
+ {"cdddr", 0x2a}, /* 00101010 */
+ {"cddar", 0x2b}, /* 00101011 */
+ {"cdadr", 0x2e}, /* 00101110 */
+ {"cdaar", 0x2f}, /* 00101111 */
+ {"caddr", 0x3a}, /* 00111010 */
+ {"cadar", 0x3b}, /* 00111011 */
+ {"caadr", 0x3e}, /* 00111110 */
+ {"caaar", 0x3f}, /* 00111111 */
+ {"cddddr", 0xaa}, /* 10101010 */
+ {"cdddar", 0xab}, /* 10101011 */
+ {"cddadr", 0xae}, /* 10101110 */
+ {"cddaar", 0xaf}, /* 10101111 */
+ {"cdaddr", 0xba}, /* 10111010 */
+ {"cdadar", 0xbb}, /* 10111011 */
+ {"cdaadr", 0xbe}, /* 10111110 */
+ {"cdaaar", 0xbf}, /* 10111111 */
+ {"cadddr", 0xea}, /* 11101010 */
+ {"caddar", 0xeb}, /* 11101011 */
+ {"cadadr", 0xee}, /* 11101110 */
+ {"cadaar", 0xef}, /* 11101111 */
+ {"caaddr", 0xfa}, /* 11111010 */
+ {"caadar", 0xfb}, /* 11111011 */
+ {"caaadr", 0xfe}, /* 11111110 */
+ {"caaaar", 0xff}, /* 11111111 */
+ {0, 0}
+};
+
+\f
+
+void
+scm_init_pairs ()
+{
+ unsigned int subnr = 0;
+
+ for (subnr = 0; cxrs[subnr].name; subnr++)
+ {
+ SCM (*pattern) () = (SCM (*) ()) (scm_t_bits) cxrs[subnr].pattern;
+ scm_c_define_subr (cxrs[subnr].name, scm_tc7_cxr, pattern);
+ }
+
+#include "libguile/pairs.x"
+}
+
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/
projects / lilypond.git / blobdiff