-/* 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, Inc., 59 Temple Place, Suite 330,
- * Boston, MA 02111-1307 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. */
-\f
-#include <stdio.h>
-#include "_scm.h"
-#include "eq.h"
-
-#include "list.h"
-
-#ifdef __STDC__
-#include <stdarg.h>
-#define var_start(x, y) va_start(x, y)
-#else
-#include <varargs.h>
-#define var_start(x, y) va_start(x)
-#endif
-
-\f
-/* creating lists */
-
-/* SCM_P won't help us deal with varargs here. */
-#ifdef __STDC__
-SCM
-scm_listify (SCM elt, ...)
-#else
-SCM
-scm_listify (elt, va_alist)
- SCM elt;
- va_dcl
-#endif
-{
- va_list foo;
- SCM answer;
- SCM *pos;
-
- var_start (foo, elt);
- answer = SCM_EOL;
- pos = &answer;
- while (elt != SCM_UNDEFINED)
- {
- *pos = scm_cons (elt, SCM_EOL);
- pos = SCM_CDRLOC (*pos);
- elt = va_arg (foo, SCM);
- }
- return answer;
-}
-
-
-SCM_PROC(s_list, "list", 0, 0, 1, scm_list);
-SCM
-scm_list(objs)
- SCM objs;
-{
- return objs;
-}
-
-
-
-\f
-/* general questions about lists --- null?, list?, length, etc. */
-
-SCM_PROC(s_null_p, "null?", 1, 0, 0, scm_null_p);
-SCM
-scm_null_p(x)
- SCM x;
-{
- return SCM_NULLP(x) ? SCM_BOOL_T : SCM_BOOL_F;
-}
-
-SCM_PROC(s_list_p, "list?", 1, 0, 0, scm_list_p);
-SCM
-scm_list_p(x)
- SCM x;
-{
- if (scm_ilength(x)<0)
- return SCM_BOOL_F;
- else
- return SCM_BOOL_T;
-}
-
-
-/* Return the length of SX, or -1 if it's not a proper list.
- This uses the "tortoise and hare" algorithm to detect "infinitely
- long" lists (i.e. lists with cycles in their cdrs), and returns -1
- if it does find one. */
-long
-scm_ilength(sx)
- SCM sx;
-{
- register long i = 0;
- register SCM tortoise = sx;
- register SCM hare = sx;
-
- do {
- if SCM_IMP(hare) return SCM_NULLP(hare) ? i : -1;
- if SCM_NCONSP(hare) return -1;
- hare = SCM_CDR(hare);
- i++;
- if SCM_IMP(hare) return SCM_NULLP(hare) ? i : -1;
- if SCM_NCONSP(hare) return -1;
- hare = SCM_CDR(hare);
- i++;
- /* For every two steps the hare takes, the tortoise takes one. */
- tortoise = SCM_CDR(tortoise);
- }
- while (hare != tortoise);
-
- /* If the tortoise ever catches the hare, then the list must contain
- a cycle. */
- return -1;
-}
-
-SCM_PROC(s_list_length, "list-length", 1, 0, 0, scm_list_length);
-SCM
-scm_list_length(x)
- SCM x;
-{
- int i;
- i = scm_ilength(x);
- SCM_ASSERT(i >= 0, x, SCM_ARG1, s_list_length);
- return SCM_MAKINUM (i);
-}
-
-
-\f
-/* appending lists */
-
-SCM_PROC (s_list_append, "list-append", 0, 0, 1, scm_list_append);
-SCM
-scm_list_append(args)
- SCM args;
-{
- SCM res = SCM_EOL;
- SCM *lloc = &res, arg;
- if SCM_IMP(args) {
- SCM_ASSERT(SCM_NULLP(args), args, SCM_ARGn, s_list_append);
- return res;
- }
- SCM_ASSERT(SCM_CONSP(args), args, SCM_ARGn, s_list_append);
- while (1) {
- arg = SCM_CAR(args);
- args = SCM_CDR(args);
- if SCM_IMP(args) {
- *lloc = arg;
- SCM_ASSERT(SCM_NULLP(args), args, SCM_ARGn, s_list_append);
- return res;
- }
- SCM_ASSERT(SCM_CONSP(args), args, SCM_ARGn, s_list_append);
- for(;SCM_NIMP(arg);arg = SCM_CDR(arg)) {
- SCM_ASSERT(SCM_CONSP(arg), arg, SCM_ARGn, s_list_append);
- *lloc = scm_cons(SCM_CAR(arg), SCM_EOL);
- lloc = SCM_CDRLOC(*lloc);
- }
- SCM_ASSERT(SCM_NULLP(arg), arg, SCM_ARGn, s_list_append);
- }
-}
-
-
-SCM_PROC (s_list_append_x, "list-append!", 0, 0, 1, scm_list_append_x);
-SCM
-scm_list_append_x(args)
- SCM args;
-{
- SCM arg;
- tail:
- if SCM_NULLP(args) return SCM_EOL;
- arg = SCM_CAR(args);
- SCM_ASSERT(SCM_NULLP(arg) || (SCM_NIMP(arg) && SCM_CONSP(arg)), arg, SCM_ARG1, s_list_append_x);
- args = SCM_CDR(args);
- if SCM_NULLP(args) return arg;
- if SCM_NULLP(arg) goto tail;
- SCM_SETCDR (scm_last_pair (arg), scm_list_append_x (args));
- return arg;
-}
-
-
-SCM_PROC(s_last_pair, "last-pair", 1, 0, 0, scm_last_pair);
-SCM
-scm_last_pair(sx)
- SCM sx;
-{
- register SCM res = sx;
- register SCM x;
-
- if (SCM_NULLP (sx))
- return SCM_EOL;
-
- SCM_ASSERT(SCM_NIMP(res) && SCM_CONSP(res), res, SCM_ARG1, s_last_pair);
- while (!0) {
- x = SCM_CDR(res);
- if (SCM_IMP(x) || SCM_NCONSP(x)) return res;
- res = x;
- x = SCM_CDR(res);
- if (SCM_IMP(x) || SCM_NCONSP(x)) return res;
- res = x;
- sx = SCM_CDR(sx);
- SCM_ASSERT(x != sx, sx, SCM_ARG1, s_last_pair);
- }
-}
-
-\f
-/* reversing lists */
-
-SCM_PROC (s_list_reverse, "list-reverse", 1, 0, 0, scm_list_reverse);
-SCM
-scm_list_reverse(lst)
- SCM lst;
-{
- SCM res = SCM_EOL;
- SCM p = lst;
- for(;SCM_NIMP(p);p = SCM_CDR(p)) {
- SCM_ASSERT(SCM_CONSP(p), lst, SCM_ARG1, s_list_reverse);
- res = scm_cons(SCM_CAR(p), res);
- }
- SCM_ASSERT(SCM_NULLP(p), lst, SCM_ARG1, s_list_reverse);
- return res;
-}
-
-SCM_PROC (s_list_reverse_x, "list-reverse!", 1, 1, 0, scm_list_reverse_x);
-SCM
-scm_list_reverse_x (lst, newtail)
- SCM lst;
- SCM newtail;
-{
- SCM old_tail;
- if (newtail == SCM_UNDEFINED)
- newtail = SCM_EOL;
-
- loop:
- if (!(SCM_NIMP (lst) && SCM_CONSP (lst)))
- return lst;
-
- old_tail = SCM_CDR (lst);
- SCM_SETCDR (lst, newtail);
- if (SCM_NULLP (old_tail))
- return lst;
-
- newtail = lst;
- lst = old_tail;
- goto loop;
-}
-
-
-\f
-/* indexing lists by element number */
-
-SCM_PROC(s_list_ref, "list-ref", 2, 0, 0, scm_list_ref);
-SCM
-scm_list_ref(lst, k)
- SCM lst;
- SCM k;
-{
- register long i;
- SCM_ASSERT(SCM_INUMP(k), k, SCM_ARG2, s_list_ref);
- i = SCM_INUM(k);
- SCM_ASSERT(i >= 0, k, SCM_ARG2, s_list_ref);
- while (i-- > 0) {
- SCM_ASRTGO(SCM_NIMP(lst) && SCM_CONSP(lst), erout);
- lst = SCM_CDR(lst);
- }
-erout: SCM_ASSERT(SCM_NIMP(lst) && SCM_CONSP(lst),
- SCM_NULLP(lst)?k:lst, SCM_NULLP(lst)?SCM_OUTOFRANGE:SCM_ARG1, s_list_ref);
- return SCM_CAR(lst);
-}
-
-SCM_PROC(s_list_set_x, "list-set!", 3, 0, 0, scm_list_set_x);
-SCM
-scm_list_set_x(lst, k, val)
- SCM lst;
- SCM k;
- SCM val;
-{
- register long i;
- SCM_ASSERT(SCM_INUMP(k), k, SCM_ARG2, s_list_set_x);
- i = SCM_INUM(k);
- SCM_ASSERT(i >= 0, k, SCM_ARG2, s_list_set_x);
- while (i-- > 0) {
- SCM_ASRTGO(SCM_NIMP(lst) && SCM_CONSP(lst), erout);
- lst = SCM_CDR(lst);
- }
-erout: SCM_ASSERT(SCM_NIMP(lst) && SCM_CONSP(lst),
- SCM_NULLP(lst)?k:lst, SCM_NULLP(lst)?SCM_OUTOFRANGE:SCM_ARG1, s_list_set_x);
- SCM_SETCAR (lst, val);
- return val;
-}
-
-
-SCM_PROC(s_list_cdr_ref, "list-cdr-ref", 2, 0, 0, scm_list_tail);
-SCM_PROC(s_list_tail, "list-tail", 2, 0, 0, scm_list_tail);
-SCM
-scm_list_tail(lst, k)
- SCM lst;
- SCM k;
-{
- register long i;
- SCM_ASSERT(SCM_INUMP(k), k, SCM_ARG2, s_list_tail);
- i = SCM_INUM(k);
- while (i-- > 0) {
- SCM_ASSERT(SCM_NIMP(lst) && SCM_CONSP(lst), lst, SCM_ARG1, s_list_tail);
- lst = SCM_CDR(lst);
- }
- return lst;
-}
-
-
-SCM_PROC(s_list_cdr_set_x, "list-cdr-set!", 3, 0, 0, scm_list_cdr_set_x);
-SCM
-scm_list_cdr_set_x(lst, k, val)
- SCM lst;
- SCM k;
- SCM val;
-{
- register long i;
- SCM_ASSERT(SCM_INUMP(k), k, SCM_ARG2, s_list_cdr_set_x);
- i = SCM_INUM(k);
- SCM_ASSERT(i >= 0, k, SCM_ARG2, s_list_cdr_set_x);
- while (i-- > 0) {
- SCM_ASRTGO(SCM_NIMP(lst) && SCM_CONSP(lst), erout);
- lst = SCM_CDR(lst);
- }
-erout: SCM_ASSERT(SCM_NIMP(lst) && SCM_CONSP(lst),
- SCM_NULLP(lst)?k:lst, SCM_NULLP(lst)?SCM_OUTOFRANGE:SCM_ARG1, s_list_cdr_set_x);
- SCM_SETCDR (lst, val);
- return val;
-}
-
-
-\f
-/* copying lists, perhaps partially */
-
-SCM_PROC(s_list_head, "list-head", 2, 0, 0, scm_list_head);
-SCM
-scm_list_head(lst, k)
- SCM lst;
- SCM k;
-{
- SCM answer;
- SCM * pos;
- register long i;
-
- SCM_ASSERT(SCM_INUMP(k), k, SCM_ARG2, s_list_head);
- answer = SCM_EOL;
- pos = &answer;
- i = SCM_INUM(k);
- while (i-- > 0)
- {
- SCM_ASSERT(SCM_NIMP(lst) && SCM_CONSP(lst), lst, SCM_ARG1, s_list_head);
- *pos = scm_cons (SCM_CAR (lst), SCM_EOL);
- pos = SCM_CDRLOC (*pos);
- lst = SCM_CDR(lst);
- }
- return answer;
-}
-
-
-SCM_PROC (s_list_copy, "list-copy", 1, 0, 0, scm_list_copy);
-SCM
-scm_list_copy (lst)
- SCM lst;
-{
- SCM newlst;
- SCM * fill_here;
- SCM from_here;
-
- newlst = SCM_EOL;
- fill_here = &newlst;
- from_here = lst;
-
- while (SCM_NIMP (from_here) && SCM_CONSP (from_here))
- {
- SCM c;
- c = scm_cons (SCM_CAR (from_here), SCM_CDR (from_here));
- *fill_here = c;
- fill_here = SCM_CDRLOC (c);
- from_here = SCM_CDR (from_here);
- }
- return newlst;
-}
-
-\f
-/* membership tests (memq, memv, etc.) */
-
-static void sloppy_mem_check SCM_P ((SCM obj, char * where, char * why));
-
-static void
-sloppy_mem_check (obj, where, why)
- SCM obj;
- char * where;
- char * why;
-{
- SCM_ASSERT ((scm_ilength (obj) >= 0), obj, where, why);
-}
-
-
-SCM_PROC (s_sloppy_memq, "sloppy-memq", 2, 0, 0, scm_sloppy_memq);
-SCM
-scm_sloppy_memq(x, lst)
- SCM x;
- SCM lst;
-{
- for(; SCM_NIMP(lst) && SCM_CONSP (lst); lst = SCM_CDR(lst))
- {
- if (SCM_CAR(lst)==x)
- return lst;
- }
- return lst;
-}
-
-
-SCM_PROC (s_sloppy_memv, "sloppy-memv", 2, 0, 0, scm_sloppy_memv);
-SCM
-scm_sloppy_memv(x, lst)
- SCM x;
- SCM lst;
-{
- for(; SCM_NIMP(lst) && SCM_CONSP (lst); lst = SCM_CDR(lst))
- {
- if (SCM_BOOL_F != scm_eqv_p (SCM_CAR(lst), x))
- return lst;
- }
- return lst;
-}
-
-
-SCM_PROC (s_sloppy_member, "sloppy-member", 2, 0, 0, scm_sloppy_member);
-SCM
-scm_sloppy_member (x, lst)
- SCM x;
- SCM lst;
-{
- for(; SCM_NIMP(lst) && SCM_CONSP (lst); lst = SCM_CDR(lst))
- {
- if (SCM_BOOL_F != scm_equal_p (SCM_CAR(lst), x))
- return lst;
- }
- return lst;
-}
-
-
-
-SCM_PROC(s_memq, "memq", 2, 0, 0, scm_memq);
-SCM
-scm_memq(x, lst)
- SCM x;
- SCM lst;
-{
- SCM answer;
- answer = scm_sloppy_memq (x, lst);
- sloppy_mem_check (answer, (char *)SCM_ARG2, s_memq);
- return (answer == SCM_EOL) ? SCM_BOOL_F : answer;
-}
-
-
-
-SCM_PROC(s_memv, "memv", 2, 0, 0, scm_memv);
-SCM
-scm_memv(x, lst)
- SCM x;
- SCM lst;
-{
- SCM answer;
- answer = scm_sloppy_memv (x, lst);
- sloppy_mem_check (answer, (char *)SCM_ARG2, s_memv);
- return (answer == SCM_EOL) ? SCM_BOOL_F : answer;
-}
-
-
-SCM_PROC(s_member, "member", 2, 0, 0, scm_member);
-SCM
-scm_member(x, lst)
- SCM x;
- SCM lst;
-{
- SCM answer;
- answer = scm_sloppy_member (x, lst);
- sloppy_mem_check (answer, (char *)SCM_ARG2, s_member);
- return (answer == SCM_EOL) ? SCM_BOOL_F : answer;
-}
-
-
-\f
-/* deleting elements from a list (delq, etc.) */
-
-SCM_PROC(s_delq_x, "delq!", 2, 0, 0, scm_delq_x);
-SCM
-scm_delq_x (item, lst)
- SCM item;
- SCM lst;
-{
- SCM walk;
- SCM *prev;
-
- for (prev = &lst, walk = lst;
- SCM_NIMP (walk) && SCM_CONSP (walk);
- walk = SCM_CDR (walk))
- {
- if (SCM_CAR (walk) == item)
- *prev = SCM_CDR (walk);
- else
- prev = SCM_CDRLOC (walk);
- }
-
- return lst;
-}
-
-
-SCM_PROC(s_delv_x, "delv!", 2, 0, 0, scm_delv_x);
-SCM
-scm_delv_x (item, lst)
- SCM item;
- SCM lst;
-{
- SCM walk;
- SCM *prev;
-
- for (prev = &lst, walk = lst;
- SCM_NIMP (walk) && SCM_CONSP (walk);
- walk = SCM_CDR (walk))
- {
- if (SCM_BOOL_F != scm_eqv_p (SCM_CAR (walk), item))
- *prev = SCM_CDR (walk);
- else
- prev = SCM_CDRLOC (walk);
- }
-
- return lst;
-}
-
-
-
-SCM_PROC(s_delete_x, "delete!", 2, 0, 0, scm_delete_x);
-SCM
-scm_delete_x (item, lst)
- SCM item;
- SCM lst;
-{
- SCM walk;
- SCM *prev;
-
- for (prev = &lst, walk = lst;
- SCM_NIMP (walk) && SCM_CONSP (walk);
- walk = SCM_CDR (walk))
- {
- if (SCM_BOOL_F != scm_equal_p (SCM_CAR (walk), item))
- *prev = SCM_CDR (walk);
- else
- prev = SCM_CDRLOC (walk);
- }
-
- return lst;
-}
-
-
-\f
-
-
-SCM_PROC (s_delq, "delq", 2, 0, 0, scm_delq);
-SCM
-scm_delq (item, lst)
- SCM item;
- SCM lst;
-{
- SCM copy;
-
- copy = scm_list_copy (lst);
- return scm_delq_x (item, copy);
-}
-
-SCM_PROC (s_delv, "delv", 2, 0, 0, scm_delv);
-SCM
-scm_delv (item, lst)
- SCM item;
- SCM lst;
-{
- SCM copy;
-
- copy = scm_list_copy (lst);
- return scm_delv_x (item, copy);
-}
-
-SCM_PROC (s_delete, "delete", 2, 0, 0, scm_delete);
-SCM
-scm_delete (item, lst)
- SCM item;
- SCM lst;
-{
- SCM copy;
-
- copy = scm_list_copy (lst);
- return scm_delete_x (item, copy);
-}
-
-
-\f
-void
-scm_init_list ()
-{
-#include "list.x"
-}
+/* Copyright (C) 1995,1996,1997,2000,2001,2003,2004
+ * 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
+#include "libguile/_scm.h"
+#include "libguile/eq.h"
+#include "libguile/lang.h"
+
+#include "libguile/validate.h"
+#include "libguile/list.h"
+#include "libguile/eval.h"
+
+#include <stdarg.h>
+
+\f
+/* creating lists */
+
+#define SCM_I_CONS(cell, x, y) \
+do { \
+ cell = scm_cell ((scm_t_bits)x, (scm_t_bits)y); \
+} while (0)
+
+SCM
+scm_list_1 (SCM e1)
+{
+ SCM c1;
+ SCM_I_CONS (c1, e1, SCM_EOL);
+ return c1;
+}
+
+SCM
+scm_list_2 (SCM e1, SCM e2)
+{
+ SCM c1, c2;
+ SCM_I_CONS (c2, e2, SCM_EOL);
+ SCM_I_CONS (c1, e1, c2);
+ return c1;
+}
+
+SCM
+scm_list_3 (SCM e1, SCM e2, SCM e3)
+{
+ SCM c1, c2, c3;
+ SCM_I_CONS (c3, e3, SCM_EOL);
+ SCM_I_CONS (c2, e2, c3);
+ SCM_I_CONS (c1, e1, c2);
+ return c1;
+}
+
+SCM
+scm_list_4 (SCM e1, SCM e2, SCM e3, SCM e4)
+{
+ return scm_cons2 (e1, e2, scm_list_2 (e3, e4));
+}
+
+SCM
+scm_list_5 (SCM e1, SCM e2, SCM e3, SCM e4, SCM e5)
+{
+ return scm_cons2 (e1, e2, scm_list_3 (e3, e4, e5));
+}
+
+SCM
+scm_list_n (SCM elt, ...)
+{
+ va_list foo;
+ SCM answer = SCM_EOL;
+ SCM *pos = &answer;
+
+ va_start (foo, elt);
+ while (! SCM_UNBNDP (elt))
+ {
+#if (SCM_DEBUG_CELL_ACCESSES == 1)
+ if (SCM_NIMP (elt))
+ SCM_VALIDATE_CELL(elt, 0);
+#endif
+ *pos = scm_cons (elt, SCM_EOL);
+ pos = SCM_CDRLOC (*pos);
+ elt = va_arg (foo, SCM);
+ }
+ va_end (foo);
+ return answer;
+}
+
+
+SCM_DEFINE (scm_make_list, "make-list", 1, 1, 0,
+ (SCM n, SCM init),
+ "Create a list containing of @var{n} elements, where each\n"
+ "element is initialized to @var{init}. @var{init} defaults to\n"
+ "the empty list @code{()} if not given.")
+#define FUNC_NAME s_scm_make_list
+{
+ unsigned nn = scm_to_uint (n);
+ unsigned i;
+ SCM ret = SCM_EOL;
+
+ if (SCM_UNBNDP (init))
+ init = SCM_EOL;
+
+ for (i = 0; i < nn; i++)
+ ret = scm_cons (init, ret);
+ return ret;
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_cons_star, "cons*", 1, 0, 1,
+ (SCM arg, SCM rest),
+ "Like @code{list}, but the last arg provides the tail of the\n"
+ "constructed list, returning @code{(cons @var{arg1} (cons\n"
+ "@var{arg2} (cons @dots{} @var{argn})))}. Requires at least one\n"
+ "argument. If given one argument, that argument is returned as\n"
+ "result. This function is called @code{list*} in some other\n"
+ "Schemes and in Common LISP.")
+#define FUNC_NAME s_scm_cons_star
+{
+ SCM ret = SCM_EOL;
+ SCM *p = &ret;
+
+ SCM_VALIDATE_REST_ARGUMENT (rest);
+
+ for ( ; scm_is_pair (rest); rest = SCM_CDR (rest))
+ {
+ *p = scm_cons (arg, SCM_EOL);
+ p = SCM_CDRLOC (*p);
+ arg = SCM_CAR (rest);
+ }
+
+ *p = arg;
+ return ret;
+}
+#undef FUNC_NAME
+
+
+\f
+/* general questions about lists --- null?, list?, length, etc. */
+
+SCM_DEFINE (scm_null_p, "null?", 1, 0, 0,
+ (SCM x),
+ "Return @code{#t} iff @var{x} is the empty list, else @code{#f}.")
+#define FUNC_NAME s_scm_null_p
+{
+ return scm_from_bool (SCM_NULL_OR_NIL_P (x));
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_list_p, "list?", 1, 0, 0,
+ (SCM x),
+ "Return @code{#t} iff @var{x} is a proper list, else @code{#f}.")
+#define FUNC_NAME s_scm_list_p
+{
+ return scm_from_bool (scm_ilength (x) >= 0);
+}
+#undef FUNC_NAME
+
+
+/* Return the length of SX, or -1 if it's not a proper list.
+ This uses the "tortoise and hare" algorithm to detect "infinitely
+ long" lists (i.e. lists with cycles in their cdrs), and returns -1
+ if it does find one. */
+long
+scm_ilength(SCM sx)
+{
+ long i = 0;
+ SCM tortoise = sx;
+ SCM hare = sx;
+
+ do {
+ if (SCM_NULL_OR_NIL_P(hare)) return i;
+ if (!scm_is_pair (hare)) return -1;
+ hare = SCM_CDR(hare);
+ i++;
+ if (SCM_NULL_OR_NIL_P(hare)) return i;
+ if (!scm_is_pair (hare)) return -1;
+ hare = SCM_CDR(hare);
+ i++;
+ /* For every two steps the hare takes, the tortoise takes one. */
+ tortoise = SCM_CDR(tortoise);
+ }
+ while (!scm_is_eq (hare, tortoise));
+
+ /* If the tortoise ever catches the hare, then the list must contain
+ a cycle. */
+ return -1;
+}
+
+
+SCM_DEFINE (scm_length, "length", 1, 0, 0,
+ (SCM lst),
+ "Return the number of elements in list @var{lst}.")
+#define FUNC_NAME s_scm_length
+{
+ long i;
+ SCM_VALIDATE_LIST_COPYLEN (1, lst, i);
+ return scm_from_long (i);
+}
+#undef FUNC_NAME
+
+
+\f
+/* appending lists */
+
+SCM_DEFINE (scm_append, "append", 0, 0, 1,
+ (SCM args),
+ "Return a list consisting of the elements the lists passed as\n"
+ "arguments.\n"
+ "@lisp\n"
+ "(append '(x) '(y)) @result{} (x y)\n"
+ "(append '(a) '(b c d)) @result{} (a b c d)\n"
+ "(append '(a (b)) '((c))) @result{} (a (b) (c))\n"
+ "@end lisp\n"
+ "The resulting list is always newly allocated, except that it\n"
+ "shares structure with the last list argument. The last\n"
+ "argument may actually be any object; an improper list results\n"
+ "if the last argument is not a proper list.\n"
+ "@lisp\n"
+ "(append '(a b) '(c . d)) @result{} (a b c . d)\n"
+ "(append '() 'a) @result{} a\n"
+ "@end lisp")
+#define FUNC_NAME s_scm_append
+{
+ SCM_VALIDATE_REST_ARGUMENT (args);
+ if (scm_is_null (args)) {
+ return SCM_EOL;
+ } else {
+ SCM res = SCM_EOL;
+ SCM *lloc = &res;
+ SCM arg = SCM_CAR (args);
+ int argnum = 1;
+ args = SCM_CDR (args);
+ while (!scm_is_null (args)) {
+ while (scm_is_pair (arg)) {
+ *lloc = scm_cons (SCM_CAR (arg), SCM_EOL);
+ lloc = SCM_CDRLOC (*lloc);
+ arg = SCM_CDR (arg);
+ }
+ SCM_VALIDATE_NULL_OR_NIL (argnum, arg);
+ arg = SCM_CAR (args);
+ args = SCM_CDR (args);
+ argnum++;
+ };
+ *lloc = arg;
+ return res;
+ }
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_append_x, "append!", 0, 0, 1,
+ (SCM lists),
+ "A destructive version of @code{append} (@pxref{Pairs and\n"
+ "Lists,,,r5rs, The Revised^5 Report on Scheme}). The cdr field\n"
+ "of each list's final pair is changed to point to the head of\n"
+ "the next list, so no consing is performed. Return\n"
+ "the mutated list.")
+#define FUNC_NAME s_scm_append_x
+{
+ SCM ret, *loc;
+ SCM_VALIDATE_REST_ARGUMENT (lists);
+
+ if (scm_is_null (lists))
+ return SCM_EOL;
+
+ loc = &ret;
+ for (;;)
+ {
+ SCM arg = SCM_CAR (lists);
+ *loc = arg;
+
+ lists = SCM_CDR (lists);
+ if (scm_is_null (lists))
+ return ret;
+
+ if (!SCM_NULL_OR_NIL_P (arg))
+ {
+ SCM_VALIDATE_CONS (SCM_ARG1, arg);
+ loc = SCM_CDRLOC (scm_last_pair (arg));
+ }
+ }
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_last_pair, "last-pair", 1, 0, 0,
+ (SCM lst),
+ "Return the last pair in @var{lst}, signalling an error if\n"
+ "@var{lst} is circular.")
+#define FUNC_NAME s_scm_last_pair
+{
+ SCM tortoise = lst;
+ SCM hare = lst;
+
+ if (SCM_NULL_OR_NIL_P (lst))
+ return lst;
+
+ SCM_VALIDATE_CONS (SCM_ARG1, lst);
+ do {
+ SCM ahead = SCM_CDR(hare);
+ if (!scm_is_pair (ahead)) return hare;
+ hare = ahead;
+ ahead = SCM_CDR(hare);
+ if (!scm_is_pair (ahead)) return hare;
+ hare = ahead;
+ tortoise = SCM_CDR(tortoise);
+ }
+ while (!scm_is_eq (hare, tortoise));
+ SCM_MISC_ERROR ("Circular structure in position 1: ~S", scm_list_1 (lst));
+}
+#undef FUNC_NAME
+
+\f
+/* reversing lists */
+
+SCM_DEFINE (scm_reverse, "reverse", 1, 0, 0,
+ (SCM lst),
+ "Return a new list that contains the elements of @var{lst} but\n"
+ "in reverse order.")
+#define FUNC_NAME s_scm_reverse
+{
+ SCM result = SCM_EOL;
+ SCM tortoise = lst;
+ SCM hare = lst;
+
+ do {
+ if (SCM_NULL_OR_NIL_P(hare)) return result;
+ SCM_ASSERT(scm_is_pair(hare), lst, 1, FUNC_NAME);
+ result = scm_cons (SCM_CAR (hare), result);
+ hare = SCM_CDR (hare);
+ if (SCM_NULL_OR_NIL_P(hare)) return result;
+ SCM_ASSERT(scm_is_pair(hare), lst, 1, FUNC_NAME);
+ result = scm_cons (SCM_CAR (hare), result);
+ hare = SCM_CDR (hare);
+ tortoise = SCM_CDR (tortoise);
+ }
+ while (!scm_is_eq (hare, tortoise));
+ SCM_MISC_ERROR ("Circular structure in position 1: ~S", scm_list_1 (lst));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_reverse_x, "reverse!", 1, 1, 0,
+ (SCM lst, SCM new_tail),
+ "A destructive version of @code{reverse} (@pxref{Pairs and Lists,,,r5rs,\n"
+ "The Revised^5 Report on Scheme}). The cdr of each cell in @var{lst} is\n"
+ "modified to point to the previous list element. Return the\n"
+ "reversed list.\n\n"
+ "Caveat: because the list is modified in place, the tail of the original\n"
+ "list now becomes its head, and the head of the original list now becomes\n"
+ "the tail. Therefore, the @var{lst} symbol to which the head of the\n"
+ "original list was bound now points to the tail. To ensure that the head\n"
+ "of the modified list is not lost, it is wise to save the return value of\n"
+ "@code{reverse!}")
+#define FUNC_NAME s_scm_reverse_x
+{
+ SCM_VALIDATE_LIST (1, lst);
+ if (SCM_UNBNDP (new_tail))
+ new_tail = SCM_EOL;
+ else
+ SCM_VALIDATE_LIST (2, new_tail);
+
+ while (!SCM_NULL_OR_NIL_P (lst))
+ {
+ SCM old_tail = SCM_CDR (lst);
+ SCM_SETCDR (lst, new_tail);
+ new_tail = lst;
+ lst = old_tail;
+ }
+ return new_tail;
+}
+#undef FUNC_NAME
+
+\f
+
+/* indexing lists by element number */
+
+SCM_DEFINE (scm_list_ref, "list-ref", 2, 0, 0,
+ (SCM list, SCM k),
+ "Return the @var{k}th element from @var{list}.")
+#define FUNC_NAME s_scm_list_ref
+{
+ SCM lst = list;
+ unsigned long int i;
+ i = scm_to_ulong (k);
+ while (scm_is_pair (lst)) {
+ if (i == 0)
+ return SCM_CAR (lst);
+ else {
+ --i;
+ lst = SCM_CDR (lst);
+ }
+ };
+ if (SCM_NULL_OR_NIL_P (lst))
+ SCM_OUT_OF_RANGE (2, k);
+ else
+ SCM_WRONG_TYPE_ARG (1, list);
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_list_set_x, "list-set!", 3, 0, 0,
+ (SCM list, SCM k, SCM val),
+ "Set the @var{k}th element of @var{list} to @var{val}.")
+#define FUNC_NAME s_scm_list_set_x
+{
+ SCM lst = list;
+ unsigned long int i = scm_to_ulong (k);
+ while (scm_is_pair (lst)) {
+ if (i == 0) {
+ SCM_SETCAR (lst, val);
+ return val;
+ } else {
+ --i;
+ lst = SCM_CDR (lst);
+ }
+ };
+ if (SCM_NULL_OR_NIL_P (lst))
+ SCM_OUT_OF_RANGE (2, k);
+ else
+ SCM_WRONG_TYPE_ARG (1, list);
+}
+#undef FUNC_NAME
+
+
+SCM_REGISTER_PROC(s_list_cdr_ref, "list-cdr-ref", 2, 0, 0, scm_list_tail);
+
+SCM_DEFINE (scm_list_tail, "list-tail", 2, 0, 0,
+ (SCM lst, SCM k),
+ "@deffnx {Scheme Procedure} list-cdr-ref lst k\n"
+ "Return the \"tail\" of @var{lst} beginning with its @var{k}th element.\n"
+ "The first element of the list is considered to be element 0.\n\n"
+ "@code{list-tail} and @code{list-cdr-ref} are identical. It may help to\n"
+ "think of @code{list-cdr-ref} as accessing the @var{k}th cdr of the list,\n"
+ "or returning the results of cdring @var{k} times down @var{lst}.")
+#define FUNC_NAME s_scm_list_tail
+{
+ size_t i = scm_to_size_t (k);
+ while (i-- > 0) {
+ SCM_VALIDATE_CONS (1, lst);
+ lst = SCM_CDR(lst);
+ }
+ return lst;
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_list_cdr_set_x, "list-cdr-set!", 3, 0, 0,
+ (SCM list, SCM k, SCM val),
+ "Set the @var{k}th cdr of @var{list} to @var{val}.")
+#define FUNC_NAME s_scm_list_cdr_set_x
+{
+ SCM lst = list;
+ size_t i = scm_to_size_t (k);
+ while (scm_is_pair (lst)) {
+ if (i == 0) {
+ SCM_SETCDR (lst, val);
+ return val;
+ } else {
+ --i;
+ lst = SCM_CDR (lst);
+ }
+ };
+ if (SCM_NULL_OR_NIL_P (lst))
+ SCM_OUT_OF_RANGE (2, k);
+ else
+ SCM_WRONG_TYPE_ARG (1, list);
+}
+#undef FUNC_NAME
+
+
+\f
+/* copying lists, perhaps partially */
+
+SCM_DEFINE (scm_list_head, "list-head", 2, 0, 0,
+ (SCM lst, SCM k),
+ "Copy the first @var{k} elements from @var{lst} into a new list, and\n"
+ "return it.")
+#define FUNC_NAME s_scm_list_head
+{
+ SCM answer;
+ SCM * pos;
+ size_t i = scm_to_size_t (k);
+
+ answer = SCM_EOL;
+ pos = &answer;
+ while (i-- > 0)
+ {
+ SCM_VALIDATE_CONS (1, lst);
+ *pos = scm_cons (SCM_CAR (lst), SCM_EOL);
+ pos = SCM_CDRLOC (*pos);
+ lst = SCM_CDR(lst);
+ }
+ return answer;
+}
+#undef FUNC_NAME
+
+
+/* Copy a list which is known to be finite. The last pair may or may not have
+ * a '() in its cdr. That is, improper lists are accepted. */
+SCM
+scm_i_finite_list_copy (SCM list)
+{
+ if (!scm_is_pair (list))
+ {
+ return list;
+ }
+ else
+ {
+ SCM tail;
+ const SCM result = tail = scm_list_1 (SCM_CAR (list));
+ list = SCM_CDR (list);
+ while (scm_is_pair (list))
+ {
+ const SCM new_tail = scm_list_1 (SCM_CAR (list));
+ SCM_SETCDR (tail, new_tail);
+ tail = new_tail;
+ list = SCM_CDR (list);
+ }
+ SCM_SETCDR (tail, list);
+
+ return result;
+ }
+}
+
+
+SCM_DEFINE (scm_list_copy, "list-copy", 1, 0, 0,
+ (SCM lst),
+ "Return a (newly-created) copy of @var{lst}.")
+#define FUNC_NAME s_scm_list_copy
+{
+ SCM newlst;
+ SCM * fill_here;
+ SCM from_here;
+
+ SCM_VALIDATE_LIST (1, lst);
+
+ newlst = SCM_EOL;
+ fill_here = &newlst;
+ from_here = lst;
+
+ while (scm_is_pair (from_here))
+ {
+ SCM c;
+ c = scm_cons (SCM_CAR (from_here), SCM_CDR (from_here));
+ *fill_here = c;
+ fill_here = SCM_CDRLOC (c);
+ from_here = SCM_CDR (from_here);
+ }
+ return newlst;
+}
+#undef FUNC_NAME
+
+
+SCM_PROC (s_list, "list", 0, 0, 1, scm_list_copy);
+SCM_SNARF_DOCS (primitive, scm_list_copy, "list", (SCM objs), 0, 0, 1,
+ "Return a list containing @var{objs}, the arguments to\n"
+ "@code{list}.")
+
+/* This used to be the code for "list", but it's wrong when used via apply
+ (it should copy the list). It seems pretty unlikely anyone would have
+ been using this from C code, since it's a no-op, but keep it for strict
+ binary compatibility. */
+SCM
+scm_list (SCM objs)
+{
+ return objs;
+}
+
+
+\f
+/* membership tests (memq, memv, etc.) */
+
+/* The function scm_c_memq returns the first sublist of list whose car is
+ * 'eq?' obj, where the sublists of list are the non-empty lists returned by
+ * (list-tail list k) for k less than the length of list. If obj does not
+ * occur in list, then #f (not the empty list) is returned.
+ * List must be a proper list, otherwise scm_c_memq may crash or loop
+ * endlessly.
+ */
+SCM
+scm_c_memq (SCM obj, SCM list)
+{
+ for (; !SCM_NULL_OR_NIL_P (list); list = SCM_CDR (list))
+ {
+ if (scm_is_eq (SCM_CAR (list), obj))
+ return list;
+ }
+ return SCM_BOOL_F;
+}
+
+
+SCM_DEFINE (scm_memq, "memq", 2, 0, 0,
+ (SCM x, SCM lst),
+ "Return the first sublist of @var{lst} whose car is @code{eq?}\n"
+ "to @var{x} where the sublists of @var{lst} are the non-empty\n"
+ "lists returned by @code{(list-tail @var{lst} @var{k})} for\n"
+ "@var{k} less than the length of @var{lst}. If @var{x} does not\n"
+ "occur in @var{lst}, then @code{#f} (not the empty list) is\n"
+ "returned.")
+#define FUNC_NAME s_scm_memq
+{
+ SCM_VALIDATE_LIST (2, lst);
+ return scm_c_memq (x, lst);
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_memv, "memv", 2, 0, 0,
+ (SCM x, SCM lst),
+ "Return the first sublist of @var{lst} whose car is @code{eqv?}\n"
+ "to @var{x} where the sublists of @var{lst} are the non-empty\n"
+ "lists returned by @code{(list-tail @var{lst} @var{k})} for\n"
+ "@var{k} less than the length of @var{lst}. If @var{x} does not\n"
+ "occur in @var{lst}, then @code{#f} (not the empty list) is\n"
+ "returned.")
+#define FUNC_NAME s_scm_memv
+{
+ SCM_VALIDATE_LIST (2, lst);
+ for (; !SCM_NULL_OR_NIL_P (lst); lst = SCM_CDR (lst))
+ {
+ if (! scm_is_false (scm_eqv_p (SCM_CAR (lst), x)))
+ return lst;
+ }
+ return SCM_BOOL_F;
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_member, "member", 2, 0, 0,
+ (SCM x, SCM lst),
+ "Return the first sublist of @var{lst} whose car is\n"
+ "@code{equal?} to @var{x} where the sublists of @var{lst} are\n"
+ "the non-empty lists returned by @code{(list-tail @var{lst}\n"
+ "@var{k})} for @var{k} less than the length of @var{lst}. If\n"
+ "@var{x} does not occur in @var{lst}, then @code{#f} (not the\n"
+ "empty list) is returned.")
+#define FUNC_NAME s_scm_member
+{
+ SCM_VALIDATE_LIST (2, lst);
+ for (; !SCM_NULL_OR_NIL_P (lst); lst = SCM_CDR (lst))
+ {
+ if (! scm_is_false (scm_equal_p (SCM_CAR (lst), x)))
+ return lst;
+ }
+ return SCM_BOOL_F;
+}
+#undef FUNC_NAME
+
+\f
+/* deleting elements from a list (delq, etc.) */
+
+SCM_DEFINE (scm_delq_x, "delq!", 2, 0, 0,
+ (SCM item, SCM lst),
+ "@deffnx {Scheme Procedure} delv! item lst\n"
+ "@deffnx {Scheme Procedure} delete! item lst\n"
+ "These procedures are destructive versions of @code{delq}, @code{delv}\n"
+ "and @code{delete}: they modify the existing @var{lst}\n"
+ "rather than creating a new list. Caveat evaluator: Like other\n"
+ "destructive list functions, these functions cannot modify the binding of\n"
+ "@var{lst}, and so cannot be used to delete the first element of\n"
+ "@var{lst} destructively.")
+#define FUNC_NAME s_scm_delq_x
+{
+ SCM walk;
+ SCM *prev;
+
+ for (prev = &lst, walk = lst;
+ scm_is_pair (walk);
+ walk = SCM_CDR (walk))
+ {
+ if (scm_is_eq (SCM_CAR (walk), item))
+ *prev = SCM_CDR (walk);
+ else
+ prev = SCM_CDRLOC (walk);
+ }
+
+ return lst;
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_delv_x, "delv!", 2, 0, 0,
+ (SCM item, SCM lst),
+ "Destructively remove all elements from @var{lst} that are\n"
+ "@code{eqv?} to @var{item}.")
+#define FUNC_NAME s_scm_delv_x
+{
+ SCM walk;
+ SCM *prev;
+
+ for (prev = &lst, walk = lst;
+ scm_is_pair (walk);
+ walk = SCM_CDR (walk))
+ {
+ if (! scm_is_false (scm_eqv_p (SCM_CAR (walk), item)))
+ *prev = SCM_CDR (walk);
+ else
+ prev = SCM_CDRLOC (walk);
+ }
+
+ return lst;
+}
+#undef FUNC_NAME
+
+
+
+SCM_DEFINE (scm_delete_x, "delete!", 2, 0, 0,
+ (SCM item, SCM lst),
+ "Destructively remove all elements from @var{lst} that are\n"
+ "@code{equal?} to @var{item}.")
+#define FUNC_NAME s_scm_delete_x
+{
+ SCM walk;
+ SCM *prev;
+
+ for (prev = &lst, walk = lst;
+ scm_is_pair (walk);
+ walk = SCM_CDR (walk))
+ {
+ if (! scm_is_false (scm_equal_p (SCM_CAR (walk), item)))
+ *prev = SCM_CDR (walk);
+ else
+ prev = SCM_CDRLOC (walk);
+ }
+
+ return lst;
+}
+#undef FUNC_NAME
+
+
+\f
+
+
+SCM_DEFINE (scm_delq, "delq", 2, 0, 0,
+ (SCM item, SCM lst),
+ "Return a newly-created copy of @var{lst} with elements\n"
+ "@code{eq?} to @var{item} removed. This procedure mirrors\n"
+ "@code{memq}: @code{delq} compares elements of @var{lst} against\n"
+ "@var{item} with @code{eq?}.")
+#define FUNC_NAME s_scm_delq
+{
+ SCM copy = scm_list_copy (lst);
+ return scm_delq_x (item, copy);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_delv, "delv", 2, 0, 0,
+ (SCM item, SCM lst),
+ "Return a newly-created copy of @var{lst} with elements\n"
+ "@code{eqv?} to @var{item} removed. This procedure mirrors\n"
+ "@code{memv}: @code{delv} compares elements of @var{lst} against\n"
+ "@var{item} with @code{eqv?}.")
+#define FUNC_NAME s_scm_delv
+{
+ SCM copy = scm_list_copy (lst);
+ return scm_delv_x (item, copy);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_delete, "delete", 2, 0, 0,
+ (SCM item, SCM lst),
+ "Return a newly-created copy of @var{lst} with elements\n"
+ "@code{equal?} to @var{item} removed. This procedure mirrors\n"
+ "@code{member}: @code{delete} compares elements of @var{lst}\n"
+ "against @var{item} with @code{equal?}.")
+#define FUNC_NAME s_scm_delete
+{
+ SCM copy = scm_list_copy (lst);
+ return scm_delete_x (item, copy);
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_delq1_x, "delq1!", 2, 0, 0,
+ (SCM item, SCM lst),
+ "Like @code{delq!}, but only deletes the first occurrence of\n"
+ "@var{item} from @var{lst}. Tests for equality using\n"
+ "@code{eq?}. See also @code{delv1!} and @code{delete1!}.")
+#define FUNC_NAME s_scm_delq1_x
+{
+ SCM walk;
+ SCM *prev;
+
+ for (prev = &lst, walk = lst;
+ scm_is_pair (walk);
+ walk = SCM_CDR (walk))
+ {
+ if (scm_is_eq (SCM_CAR (walk), item))
+ {
+ *prev = SCM_CDR (walk);
+ break;
+ }
+ else
+ prev = SCM_CDRLOC (walk);
+ }
+
+ return lst;
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_delv1_x, "delv1!", 2, 0, 0,
+ (SCM item, SCM lst),
+ "Like @code{delv!}, but only deletes the first occurrence of\n"
+ "@var{item} from @var{lst}. Tests for equality using\n"
+ "@code{eqv?}. See also @code{delq1!} and @code{delete1!}.")
+#define FUNC_NAME s_scm_delv1_x
+{
+ SCM walk;
+ SCM *prev;
+
+ for (prev = &lst, walk = lst;
+ scm_is_pair (walk);
+ walk = SCM_CDR (walk))
+ {
+ if (! scm_is_false (scm_eqv_p (SCM_CAR (walk), item)))
+ {
+ *prev = SCM_CDR (walk);
+ break;
+ }
+ else
+ prev = SCM_CDRLOC (walk);
+ }
+
+ return lst;
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_delete1_x, "delete1!", 2, 0, 0,
+ (SCM item, SCM lst),
+ "Like @code{delete!}, but only deletes the first occurrence of\n"
+ "@var{item} from @var{lst}. Tests for equality using\n"
+ "@code{equal?}. See also @code{delq1!} and @code{delv1!}.")
+#define FUNC_NAME s_scm_delete1_x
+{
+ SCM walk;
+ SCM *prev;
+
+ for (prev = &lst, walk = lst;
+ scm_is_pair (walk);
+ walk = SCM_CDR (walk))
+ {
+ if (! scm_is_false (scm_equal_p (SCM_CAR (walk), item)))
+ {
+ *prev = SCM_CDR (walk);
+ break;
+ }
+ else
+ prev = SCM_CDRLOC (walk);
+ }
+
+ return lst;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_filter, "filter", 2, 0, 0,
+ (SCM pred, SCM list),
+ "Return all the elements of 2nd arg @var{list} that satisfy predicate @var{pred}.\n"
+ "The list is not disordered -- elements that appear in the result list occur\n"
+ "in the same order as they occur in the argument list. The returned list may\n"
+ "share a common tail with the argument list. The dynamic order in which the\n"
+ "various applications of pred are made is not specified.\n\n"
+ "@lisp\n"
+ "(filter even? '(0 7 8 8 43 -4)) => (0 8 8 -4)\n"
+ "@end lisp")
+#define FUNC_NAME s_scm_filter
+{
+ scm_t_trampoline_1 call = scm_trampoline_1 (pred);
+ SCM walk;
+ SCM *prev;
+ SCM res = SCM_EOL;
+ SCM_ASSERT (call, pred, 1, FUNC_NAME);
+ SCM_VALIDATE_LIST (2, list);
+
+ for (prev = &res, walk = list;
+ scm_is_pair (walk);
+ walk = SCM_CDR (walk))
+ {
+ if (scm_is_true (call (pred, SCM_CAR (walk))))
+ {
+ *prev = scm_cons (SCM_CAR (walk), SCM_EOL);
+ prev = SCM_CDRLOC (*prev);
+ }
+ }
+
+ return res;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_filter_x, "filter!", 2, 0, 0,
+ (SCM pred, SCM list),
+ "Linear-update variant of @code{filter}.")
+#define FUNC_NAME s_scm_filter_x
+{
+ scm_t_trampoline_1 call = scm_trampoline_1 (pred);
+ SCM walk;
+ SCM *prev;
+ SCM_ASSERT (call, pred, 1, FUNC_NAME);
+ SCM_VALIDATE_LIST (2, list);
+
+ for (prev = &list, walk = list;
+ scm_is_pair (walk);
+ walk = SCM_CDR (walk))
+ {
+ if (scm_is_true (call (pred, SCM_CAR (walk))))
+ prev = SCM_CDRLOC (walk);
+ else
+ *prev = SCM_CDR (walk);
+ }
+
+ return list;
+}
+#undef FUNC_NAME
+
+\f
+void
+scm_init_list ()
+{
+#include "libguile/list.x"
+}
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/
HCoop / bpt / guile.git / blobdiff