--- /dev/null
+/* Copyright (C) 1995,1996,1998,2000,2001, 2004, 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 <string.h>
+#include <stdio.h>
+
+#include "libguile/_scm.h"
+#include "libguile/chars.h"
+#include "libguile/root.h"
+#include "libguile/strings.h"
+#include "libguile/deprecation.h"
+#include "libguile/validate.h"
+#include "libguile/dynwind.h"
+
+\f
+
+/* {Strings}
+ */
+
+
+/* Stringbufs
+ *
+ * XXX - keeping an accurate refcount during GC seems to be quite
+ * tricky, so we just keep score of whether a stringbuf might be
+ * shared, not wether it definitely is.
+ *
+ * The scheme I (mvo) tried to keep an accurate reference count would
+ * recount all strings that point to a stringbuf during the mark-phase
+ * of the GC. This was done since one cannot access the stringbuf of
+ * a string when that string is freed (in order to decrease the
+ * reference count). The memory of the stringbuf might have been
+ * reused already for something completely different.
+ *
+ * This recounted worked for a small number of threads beating on
+ * cow-strings, but it failed randomly with more than 10 threads, say.
+ * I couldn't figure out what went wrong, so I used the conservative
+ * approach implemented below.
+ *
+ * A stringbuf needs to know its length, but only so that it can be
+ * reported when the stringbuf is freed.
+ *
+ * Stringbufs (and strings) are not stored very compactly: a stringbuf
+ * has room for about 2*sizeof(scm_t_bits)-1 bytes additional
+ * information. As a compensation, the code below is made more
+ * complicated by storing small strings inline in the double cell of a
+ * stringbuf. So we have fixstrings and bigstrings...
+ */
+
+#define STRINGBUF_F_SHARED 0x100
+#define STRINGBUF_F_INLINE 0x200
+
+#define STRINGBUF_TAG scm_tc7_stringbuf
+#define STRINGBUF_SHARED(buf) (SCM_CELL_WORD_0(buf) & STRINGBUF_F_SHARED)
+#define STRINGBUF_INLINE(buf) (SCM_CELL_WORD_0(buf) & STRINGBUF_F_INLINE)
+
+#define STRINGBUF_OUTLINE_CHARS(buf) ((char *)SCM_CELL_WORD_1(buf))
+#define STRINGBUF_OUTLINE_LENGTH(buf) (SCM_CELL_WORD_2(buf))
+#define STRINGBUF_INLINE_CHARS(buf) ((char *)SCM_CELL_OBJECT_LOC(buf,1))
+#define STRINGBUF_INLINE_LENGTH(buf) (((size_t)SCM_CELL_WORD_0(buf))>>16)
+
+#define STRINGBUF_CHARS(buf) (STRINGBUF_INLINE (buf) \
+ ? STRINGBUF_INLINE_CHARS (buf) \
+ : STRINGBUF_OUTLINE_CHARS (buf))
+#define STRINGBUF_LENGTH(buf) (STRINGBUF_INLINE (buf) \
+ ? STRINGBUF_INLINE_LENGTH (buf) \
+ : STRINGBUF_OUTLINE_LENGTH (buf))
+
+#define STRINGBUF_MAX_INLINE_LEN (3*sizeof(scm_t_bits))
+
+#define SET_STRINGBUF_SHARED(buf) \
+ (SCM_SET_CELL_WORD_0 ((buf), SCM_CELL_WORD_0 (buf) | STRINGBUF_F_SHARED))
+
+#if SCM_DEBUG
+static size_t lenhist[1001];
+#endif
+
+static SCM
+make_stringbuf (size_t len)
+{
+ /* XXX - for the benefit of SCM_STRING_CHARS, SCM_SYMBOL_CHARS and
+ scm_i_symbol_chars, all stringbufs are null-terminated. Once
+ SCM_STRING_CHARS and SCM_SYMBOL_CHARS are removed and the code
+ has been changed for scm_i_symbol_chars, this null-termination
+ can be dropped.
+ */
+
+#if SCM_DEBUG
+ if (len < 1000)
+ lenhist[len]++;
+ else
+ lenhist[1000]++;
+#endif
+
+ if (len <= STRINGBUF_MAX_INLINE_LEN-1)
+ {
+ return scm_double_cell (STRINGBUF_TAG | STRINGBUF_F_INLINE | (len << 16),
+ 0, 0, 0);
+ }
+ else
+ {
+ char *mem = scm_gc_malloc (len+1, "string");
+ mem[len] = '\0';
+ return scm_double_cell (STRINGBUF_TAG, (scm_t_bits) mem,
+ (scm_t_bits) len, (scm_t_bits) 0);
+ }
+}
+
+/* Return a new stringbuf whose underlying storage consists of the LEN+1
+ octets pointed to by STR (the last octet is zero). */
+SCM
+scm_i_take_stringbufn (char *str, size_t len)
+{
+ scm_gc_register_collectable_memory (str, len + 1, "stringbuf");
+
+ return scm_double_cell (STRINGBUF_TAG, (scm_t_bits) str,
+ (scm_t_bits) len, (scm_t_bits) 0);
+}
+
+SCM
+scm_i_stringbuf_mark (SCM buf)
+{
+ return SCM_BOOL_F;
+}
+
+void
+scm_i_stringbuf_free (SCM buf)
+{
+ if (!STRINGBUF_INLINE (buf))
+ scm_gc_free (STRINGBUF_OUTLINE_CHARS (buf),
+ STRINGBUF_OUTLINE_LENGTH (buf) + 1, "string");
+}
+
+scm_i_pthread_mutex_t stringbuf_write_mutex = SCM_I_PTHREAD_MUTEX_INITIALIZER;
+
+/* Copy-on-write strings.
+ */
+
+#define STRING_TAG scm_tc7_string
+
+#define STRING_STRINGBUF(str) (SCM_CELL_OBJECT_1(str))
+#define STRING_START(str) ((size_t)SCM_CELL_WORD_2(str))
+#define STRING_LENGTH(str) ((size_t)SCM_CELL_WORD_3(str))
+
+#define SET_STRING_STRINGBUF(str,buf) (SCM_SET_CELL_OBJECT_1(str,buf))
+#define SET_STRING_START(str,start) (SCM_SET_CELL_WORD_2(str,start))
+
+#define IS_STRING(str) (SCM_NIMP(str) && SCM_TYP7(str) == STRING_TAG)
+
+/* Read-only strings.
+ */
+
+#define RO_STRING_TAG (scm_tc7_string + 0x200)
+#define IS_RO_STRING(str) (SCM_CELL_TYPE(str)==RO_STRING_TAG)
+
+/* Mutation-sharing substrings
+ */
+
+#define SH_STRING_TAG (scm_tc7_string + 0x100)
+
+#define SH_STRING_STRING(sh) (SCM_CELL_OBJECT_1(sh))
+/* START and LENGTH as for STRINGs. */
+
+#define IS_SH_STRING(str) (SCM_CELL_TYPE(str)==SH_STRING_TAG)
+
+SCM
+scm_i_make_string (size_t len, char **charsp)
+{
+ SCM buf = make_stringbuf (len);
+ SCM res;
+ if (charsp)
+ *charsp = STRINGBUF_CHARS (buf);
+ res = scm_double_cell (STRING_TAG, SCM_UNPACK(buf),
+ (scm_t_bits)0, (scm_t_bits) len);
+ return res;
+}
+
+static void
+validate_substring_args (SCM str, size_t start, size_t end)
+{
+ if (!IS_STRING (str))
+ scm_wrong_type_arg_msg (NULL, 0, str, "string");
+ if (start > STRING_LENGTH (str))
+ scm_out_of_range (NULL, scm_from_size_t (start));
+ if (end > STRING_LENGTH (str) || end < start)
+ scm_out_of_range (NULL, scm_from_size_t (end));
+}
+
+static inline void
+get_str_buf_start (SCM *str, SCM *buf, size_t *start)
+{
+ *start = STRING_START (*str);
+ if (IS_SH_STRING (*str))
+ {
+ *str = SH_STRING_STRING (*str);
+ *start += STRING_START (*str);
+ }
+ *buf = STRING_STRINGBUF (*str);
+}
+
+SCM
+scm_i_substring (SCM str, size_t start, size_t end)
+{
+ SCM buf;
+ size_t str_start;
+ get_str_buf_start (&str, &buf, &str_start);
+ scm_i_pthread_mutex_lock (&stringbuf_write_mutex);
+ SET_STRINGBUF_SHARED (buf);
+ scm_i_pthread_mutex_unlock (&stringbuf_write_mutex);
+ return scm_double_cell (STRING_TAG, SCM_UNPACK(buf),
+ (scm_t_bits)str_start + start,
+ (scm_t_bits) end - start);
+}
+
+SCM
+scm_i_substring_read_only (SCM str, size_t start, size_t end)
+{
+ SCM buf;
+ size_t str_start;
+ get_str_buf_start (&str, &buf, &str_start);
+ scm_i_pthread_mutex_lock (&stringbuf_write_mutex);
+ SET_STRINGBUF_SHARED (buf);
+ scm_i_pthread_mutex_unlock (&stringbuf_write_mutex);
+ return scm_double_cell (RO_STRING_TAG, SCM_UNPACK(buf),
+ (scm_t_bits)str_start + start,
+ (scm_t_bits) end - start);
+}
+
+SCM
+scm_i_substring_copy (SCM str, size_t start, size_t end)
+{
+ size_t len = end - start;
+ SCM buf, my_buf;
+ size_t str_start;
+ get_str_buf_start (&str, &buf, &str_start);
+ my_buf = make_stringbuf (len);
+ memcpy (STRINGBUF_CHARS (my_buf),
+ STRINGBUF_CHARS (buf) + str_start + start, len);
+ scm_remember_upto_here_1 (buf);
+ return scm_double_cell (STRING_TAG, SCM_UNPACK(my_buf),
+ (scm_t_bits)0, (scm_t_bits) len);
+}
+
+SCM
+scm_i_substring_shared (SCM str, size_t start, size_t end)
+{
+ if (start == 0 && end == STRING_LENGTH (str))
+ return str;
+ else
+ {
+ size_t len = end - start;
+ if (IS_SH_STRING (str))
+ {
+ start += STRING_START (str);
+ str = SH_STRING_STRING (str);
+ }
+ return scm_double_cell (SH_STRING_TAG, SCM_UNPACK(str),
+ (scm_t_bits)start, (scm_t_bits) len);
+ }
+}
+
+SCM
+scm_c_substring (SCM str, size_t start, size_t end)
+{
+ validate_substring_args (str, start, end);
+ return scm_i_substring (str, start, end);
+}
+
+SCM
+scm_c_substring_read_only (SCM str, size_t start, size_t end)
+{
+ validate_substring_args (str, start, end);
+ return scm_i_substring_read_only (str, start, end);
+}
+
+SCM
+scm_c_substring_copy (SCM str, size_t start, size_t end)
+{
+ validate_substring_args (str, start, end);
+ return scm_i_substring_copy (str, start, end);
+}
+
+SCM
+scm_c_substring_shared (SCM str, size_t start, size_t end)
+{
+ validate_substring_args (str, start, end);
+ return scm_i_substring_shared (str, start, end);
+}
+
+SCM
+scm_i_string_mark (SCM str)
+{
+ if (IS_SH_STRING (str))
+ return SH_STRING_STRING (str);
+ else
+ return STRING_STRINGBUF (str);
+}
+
+void
+scm_i_string_free (SCM str)
+{
+}
+
+/* Internal accessors
+ */
+
+size_t
+scm_i_string_length (SCM str)
+{
+ return STRING_LENGTH (str);
+}
+
+const char *
+scm_i_string_chars (SCM str)
+{
+ SCM buf;
+ size_t start;
+ get_str_buf_start (&str, &buf, &start);
+ return STRINGBUF_CHARS (buf) + start;
+}
+
+char *
+scm_i_string_writable_chars (SCM orig_str)
+{
+ SCM buf, str = orig_str;
+ size_t start;
+
+ get_str_buf_start (&str, &buf, &start);
+ if (IS_RO_STRING (str))
+ scm_misc_error (NULL, "string is read-only: ~s", scm_list_1 (orig_str));
+
+ scm_i_pthread_mutex_lock (&stringbuf_write_mutex);
+ if (STRINGBUF_SHARED (buf))
+ {
+ /* Clone stringbuf. For this, we put all threads to sleep.
+ */
+
+ size_t len = STRING_LENGTH (str);
+ SCM new_buf;
+
+ scm_i_pthread_mutex_unlock (&stringbuf_write_mutex);
+
+ new_buf = make_stringbuf (len);
+ memcpy (STRINGBUF_CHARS (new_buf),
+ STRINGBUF_CHARS (buf) + STRING_START (str), len);
+
+ scm_i_thread_put_to_sleep ();
+ SET_STRING_STRINGBUF (str, new_buf);
+ start -= STRING_START (str);
+ SET_STRING_START (str, 0);
+ scm_i_thread_wake_up ();
+
+ buf = new_buf;
+
+ scm_i_pthread_mutex_lock (&stringbuf_write_mutex);
+ }
+
+ return STRINGBUF_CHARS (buf) + start;
+}
+
+void
+scm_i_string_stop_writing (void)
+{
+ scm_i_pthread_mutex_unlock (&stringbuf_write_mutex);
+}
+
+/* Symbols.
+
+ Basic symbol creation and accessing is done here, the rest is in
+ symbols.[hc]. This has been done to keep stringbufs and the
+ internals of strings and string-like objects confined to this file.
+*/
+
+#define SYMBOL_STRINGBUF SCM_CELL_OBJECT_1
+
+SCM
+scm_i_make_symbol (SCM name, scm_t_bits flags,
+ unsigned long hash, SCM props)
+{
+ SCM buf;
+ size_t start = STRING_START (name);
+ size_t length = STRING_LENGTH (name);
+
+ if (IS_SH_STRING (name))
+ {
+ name = SH_STRING_STRING (name);
+ start += STRING_START (name);
+ }
+ buf = SYMBOL_STRINGBUF (name);
+
+ if (start == 0 && length == STRINGBUF_LENGTH (buf))
+ {
+ /* reuse buf. */
+ scm_i_pthread_mutex_lock (&stringbuf_write_mutex);
+ SET_STRINGBUF_SHARED (buf);
+ scm_i_pthread_mutex_unlock (&stringbuf_write_mutex);
+ }
+ else
+ {
+ /* make new buf. */
+ SCM new_buf = make_stringbuf (length);
+ memcpy (STRINGBUF_CHARS (new_buf),
+ STRINGBUF_CHARS (buf) + start, length);
+ buf = new_buf;
+ }
+ return scm_double_cell (scm_tc7_symbol | flags, SCM_UNPACK (buf),
+ (scm_t_bits) hash, SCM_UNPACK (props));
+}
+
+SCM
+scm_i_c_make_symbol (const char *name, size_t len,
+ scm_t_bits flags, unsigned long hash, SCM props)
+{
+ SCM buf = make_stringbuf (len);
+ memcpy (STRINGBUF_CHARS (buf), name, len);
+
+ return scm_double_cell (scm_tc7_symbol | flags, SCM_UNPACK (buf),
+ (scm_t_bits) hash, SCM_UNPACK (props));
+}
+
+/* Return a new symbol that uses the LEN bytes pointed to by NAME as its
+ underlying storage. */
+SCM
+scm_i_c_take_symbol (char *name, size_t len,
+ scm_t_bits flags, unsigned long hash, SCM props)
+{
+ SCM buf = scm_i_take_stringbufn (name, len);
+
+ return scm_double_cell (scm_tc7_symbol | flags, SCM_UNPACK (buf),
+ (scm_t_bits) hash, SCM_UNPACK (props));
+}
+
+size_t
+scm_i_symbol_length (SCM sym)
+{
+ return STRINGBUF_LENGTH (SYMBOL_STRINGBUF (sym));
+}
+
+size_t
+scm_c_symbol_length (SCM sym)
+#define FUNC_NAME "scm_c_symbol_length"
+{
+ SCM_VALIDATE_SYMBOL (1, sym);
+
+ return STRINGBUF_LENGTH (SYMBOL_STRINGBUF (sym));
+}
+#undef FUNC_NAME
+
+const char *
+scm_i_symbol_chars (SCM sym)
+{
+ SCM buf = SYMBOL_STRINGBUF (sym);
+ return STRINGBUF_CHARS (buf);
+}
+
+SCM
+scm_i_symbol_mark (SCM sym)
+{
+ scm_gc_mark (SYMBOL_STRINGBUF (sym));
+ return SCM_CELL_OBJECT_3 (sym);
+}
+
+void
+scm_i_symbol_free (SCM sym)
+{
+}
+
+SCM
+scm_i_symbol_substring (SCM sym, size_t start, size_t end)
+{
+ SCM buf = SYMBOL_STRINGBUF (sym);
+ scm_i_pthread_mutex_lock (&stringbuf_write_mutex);
+ SET_STRINGBUF_SHARED (buf);
+ scm_i_pthread_mutex_unlock (&stringbuf_write_mutex);
+ return scm_double_cell (RO_STRING_TAG, SCM_UNPACK (buf),
+ (scm_t_bits)start, (scm_t_bits) end - start);
+}
+
+/* Debugging
+ */
+
+#if SCM_DEBUG
+
+SCM scm_sys_string_dump (SCM);
+SCM scm_sys_symbol_dump (SCM);
+SCM scm_sys_stringbuf_hist (void);
+
+SCM_DEFINE (scm_sys_string_dump, "%string-dump", 1, 0, 0,
+ (SCM str),
+ "")
+#define FUNC_NAME s_scm_sys_string_dump
+{
+ SCM_VALIDATE_STRING (1, str);
+ fprintf (stderr, "%p:\n", str);
+ fprintf (stderr, " start: %u\n", STRING_START (str));
+ fprintf (stderr, " len: %u\n", STRING_LENGTH (str));
+ if (IS_SH_STRING (str))
+ {
+ fprintf (stderr, " string: %p\n", SH_STRING_STRING (str));
+ fprintf (stderr, "\n");
+ scm_sys_string_dump (SH_STRING_STRING (str));
+ }
+ else
+ {
+ SCM buf = STRING_STRINGBUF (str);
+ fprintf (stderr, " buf: %p\n", buf);
+ fprintf (stderr, " chars: %p\n", STRINGBUF_CHARS (buf));
+ fprintf (stderr, " length: %u\n", STRINGBUF_LENGTH (buf));
+ fprintf (stderr, " flags: %x\n", (SCM_CELL_WORD_0 (buf) & 0x300));
+ }
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_sys_symbol_dump, "%symbol-dump", 1, 0, 0,
+ (SCM sym),
+ "")
+#define FUNC_NAME s_scm_sys_symbol_dump
+{
+ SCM_VALIDATE_SYMBOL (1, sym);
+ fprintf (stderr, "%p:\n", sym);
+ fprintf (stderr, " hash: %lu\n", scm_i_symbol_hash (sym));
+ {
+ SCM buf = SYMBOL_STRINGBUF (sym);
+ fprintf (stderr, " buf: %p\n", buf);
+ fprintf (stderr, " chars: %p\n", STRINGBUF_CHARS (buf));
+ fprintf (stderr, " length: %u\n", STRINGBUF_LENGTH (buf));
+ fprintf (stderr, " shared: %u\n", STRINGBUF_SHARED (buf));
+ }
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_sys_stringbuf_hist, "%stringbuf-hist", 0, 0, 0,
+ (void),
+ "")
+#define FUNC_NAME s_scm_sys_stringbuf_hist
+{
+ int i;
+ for (i = 0; i < 1000; i++)
+ if (lenhist[i])
+ fprintf (stderr, " %3d: %u\n", i, lenhist[i]);
+ fprintf (stderr, ">999: %u\n", lenhist[1000]);
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+#endif
+
+\f
+
+SCM_DEFINE (scm_string_p, "string?", 1, 0, 0,
+ (SCM obj),
+ "Return @code{#t} if @var{obj} is a string, else @code{#f}.")
+#define FUNC_NAME s_scm_string_p
+{
+ return scm_from_bool (IS_STRING (obj));
+}
+#undef FUNC_NAME
+
+
+SCM_REGISTER_PROC (s_scm_list_to_string, "list->string", 1, 0, 0, scm_string);
+
+SCM_DEFINE (scm_string, "string", 0, 0, 1,
+ (SCM chrs),
+ "@deffnx {Scheme Procedure} list->string chrs\n"
+ "Return a newly allocated string composed of the arguments,\n"
+ "@var{chrs}.")
+#define FUNC_NAME s_scm_string
+{
+ SCM result;
+ size_t len;
+ char *data;
+
+ {
+ long i = scm_ilength (chrs);
+
+ SCM_ASSERT (i >= 0, chrs, SCM_ARG1, FUNC_NAME);
+ len = i;
+ }
+
+ result = scm_i_make_string (len, &data);
+ while (len > 0 && scm_is_pair (chrs))
+ {
+ SCM elt = SCM_CAR (chrs);
+
+ SCM_VALIDATE_CHAR (SCM_ARGn, elt);
+ *data++ = SCM_CHAR (elt);
+ chrs = SCM_CDR (chrs);
+ len--;
+ }
+ if (len > 0)
+ scm_misc_error (NULL, "list changed while constructing string", SCM_EOL);
+ if (!scm_is_null (chrs))
+ scm_wrong_type_arg_msg (NULL, 0, chrs, "proper list");
+
+ return result;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_make_string, "make-string", 1, 1, 0,
+ (SCM k, SCM chr),
+ "Return a newly allocated string of\n"
+ "length @var{k}. If @var{chr} is given, then all elements of\n"
+ "the string are initialized to @var{chr}, otherwise the contents\n"
+ "of the @var{string} are unspecified.")
+#define FUNC_NAME s_scm_make_string
+{
+ return scm_c_make_string (scm_to_size_t (k), chr);
+}
+#undef FUNC_NAME
+
+SCM
+scm_c_make_string (size_t len, SCM chr)
+#define FUNC_NAME NULL
+{
+ char *dst;
+ SCM res = scm_i_make_string (len, &dst);
+
+ if (!SCM_UNBNDP (chr))
+ {
+ SCM_VALIDATE_CHAR (0, chr);
+ memset (dst, SCM_CHAR (chr), len);
+ }
+
+ return res;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_string_length, "string-length", 1, 0, 0,
+ (SCM string),
+ "Return the number of characters in @var{string}.")
+#define FUNC_NAME s_scm_string_length
+{
+ SCM_VALIDATE_STRING (1, string);
+ return scm_from_size_t (STRING_LENGTH (string));
+}
+#undef FUNC_NAME
+
+size_t
+scm_c_string_length (SCM string)
+{
+ if (!IS_STRING (string))
+ scm_wrong_type_arg_msg (NULL, 0, string, "string");
+ return STRING_LENGTH (string);
+}
+
+SCM_DEFINE (scm_string_ref, "string-ref", 2, 0, 0,
+ (SCM str, SCM k),
+ "Return character @var{k} of @var{str} using zero-origin\n"
+ "indexing. @var{k} must be a valid index of @var{str}.")
+#define FUNC_NAME s_scm_string_ref
+{
+ size_t len;
+ unsigned long idx;
+
+ SCM_VALIDATE_STRING (1, str);
+
+ len = scm_i_string_length (str);
+ if (SCM_LIKELY (len > 0))
+ idx = scm_to_unsigned_integer (k, 0, len - 1);
+ else
+ scm_out_of_range (NULL, k);
+
+ return SCM_MAKE_CHAR (scm_i_string_chars (str)[idx]);
+}
+#undef FUNC_NAME
+
+SCM
+scm_c_string_ref (SCM str, size_t p)
+{
+ if (p >= scm_i_string_length (str))
+ scm_out_of_range (NULL, scm_from_size_t (p));
+ return SCM_MAKE_CHAR (scm_i_string_chars (str)[p]);
+}
+
+SCM_DEFINE (scm_string_set_x, "string-set!", 3, 0, 0,
+ (SCM str, SCM k, SCM chr),
+ "Store @var{chr} in element @var{k} of @var{str} and return\n"
+ "an unspecified value. @var{k} must be a valid index of\n"
+ "@var{str}.")
+#define FUNC_NAME s_scm_string_set_x
+{
+ size_t len;
+ unsigned long idx;
+
+ SCM_VALIDATE_STRING (1, str);
+
+ len = scm_i_string_length (str);
+ if (SCM_LIKELY (len > 0))
+ idx = scm_to_unsigned_integer (k, 0, len - 1);
+ else
+ scm_out_of_range (NULL, k);
+
+ SCM_VALIDATE_CHAR (3, chr);
+ {
+ char *dst = scm_i_string_writable_chars (str);
+ dst[idx] = SCM_CHAR (chr);
+ scm_i_string_stop_writing ();
+ }
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+void
+scm_c_string_set_x (SCM str, size_t p, SCM chr)
+{
+ if (p >= scm_i_string_length (str))
+ scm_out_of_range (NULL, scm_from_size_t (p));
+ {
+ char *dst = scm_i_string_writable_chars (str);
+ dst[p] = SCM_CHAR (chr);
+ scm_i_string_stop_writing ();
+ }
+}
+
+SCM_DEFINE (scm_substring, "substring", 2, 1, 0,
+ (SCM str, SCM start, SCM end),
+ "Return a newly allocated string formed from the characters\n"
+ "of @var{str} beginning with index @var{start} (inclusive) and\n"
+ "ending with index @var{end} (exclusive).\n"
+ "@var{str} must be a string, @var{start} and @var{end} must be\n"
+ "exact integers satisfying:\n\n"
+ "0 <= @var{start} <= @var{end} <= (string-length @var{str}).")
+#define FUNC_NAME s_scm_substring
+{
+ size_t len, from, to;
+
+ SCM_VALIDATE_STRING (1, str);
+ len = scm_i_string_length (str);
+ from = scm_to_unsigned_integer (start, 0, len);
+ if (SCM_UNBNDP (end))
+ to = len;
+ else
+ to = scm_to_unsigned_integer (end, from, len);
+ return scm_i_substring (str, from, to);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_substring_read_only, "substring/read-only", 2, 1, 0,
+ (SCM str, SCM start, SCM end),
+ "Return a newly allocated string formed from the characters\n"
+ "of @var{str} beginning with index @var{start} (inclusive) and\n"
+ "ending with index @var{end} (exclusive).\n"
+ "@var{str} must be a string, @var{start} and @var{end} must be\n"
+ "exact integers satisfying:\n"
+ "\n"
+ "0 <= @var{start} <= @var{end} <= (string-length @var{str}).\n"
+ "\n"
+ "The returned string is read-only.\n")
+#define FUNC_NAME s_scm_substring_read_only
+{
+ size_t len, from, to;
+
+ SCM_VALIDATE_STRING (1, str);
+ len = scm_i_string_length (str);
+ from = scm_to_unsigned_integer (start, 0, len);
+ if (SCM_UNBNDP (end))
+ to = len;
+ else
+ to = scm_to_unsigned_integer (end, from, len);
+ return scm_i_substring_read_only (str, from, to);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_substring_copy, "substring/copy", 2, 1, 0,
+ (SCM str, SCM start, SCM end),
+ "Return a newly allocated string formed from the characters\n"
+ "of @var{str} beginning with index @var{start} (inclusive) and\n"
+ "ending with index @var{end} (exclusive).\n"
+ "@var{str} must be a string, @var{start} and @var{end} must be\n"
+ "exact integers satisfying:\n\n"
+ "0 <= @var{start} <= @var{end} <= (string-length @var{str}).")
+#define FUNC_NAME s_scm_substring_copy
+{
+ /* For the Scheme version, START is mandatory, but for the C
+ version, it is optional. See scm_string_copy in srfi-13.c for a
+ rationale.
+ */
+
+ size_t from, to;
+
+ SCM_VALIDATE_STRING (1, str);
+ scm_i_get_substring_spec (scm_i_string_length (str),
+ start, &from, end, &to);
+ return scm_i_substring_copy (str, from, to);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_substring_shared, "substring/shared", 2, 1, 0,
+ (SCM str, SCM start, SCM end),
+ "Return string that indirectly refers to the characters\n"
+ "of @var{str} beginning with index @var{start} (inclusive) and\n"
+ "ending with index @var{end} (exclusive).\n"
+ "@var{str} must be a string, @var{start} and @var{end} must be\n"
+ "exact integers satisfying:\n\n"
+ "0 <= @var{start} <= @var{end} <= (string-length @var{str}).")
+#define FUNC_NAME s_scm_substring_shared
+{
+ size_t len, from, to;
+
+ SCM_VALIDATE_STRING (1, str);
+ len = scm_i_string_length (str);
+ from = scm_to_unsigned_integer (start, 0, len);
+ if (SCM_UNBNDP (end))
+ to = len;
+ else
+ to = scm_to_unsigned_integer (end, from, len);
+ return scm_i_substring_shared (str, from, to);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_string_append, "string-append", 0, 0, 1,
+ (SCM args),
+ "Return a newly allocated string whose characters form the\n"
+ "concatenation of the given strings, @var{args}.")
+#define FUNC_NAME s_scm_string_append
+{
+ SCM res;
+ size_t i = 0;
+ SCM l, s;
+ char *data;
+
+ SCM_VALIDATE_REST_ARGUMENT (args);
+ for (l = args; !scm_is_null (l); l = SCM_CDR (l))
+ {
+ s = SCM_CAR (l);
+ SCM_VALIDATE_STRING (SCM_ARGn, s);
+ i += scm_i_string_length (s);
+ }
+ res = scm_i_make_string (i, &data);
+ for (l = args; !scm_is_null (l); l = SCM_CDR (l))
+ {
+ size_t len;
+ s = SCM_CAR (l);
+ SCM_VALIDATE_STRING (SCM_ARGn, s);
+ len = scm_i_string_length (s);
+ memcpy (data, scm_i_string_chars (s), len);
+ data += len;
+ scm_remember_upto_here_1 (s);
+ }
+ return res;
+}
+#undef FUNC_NAME
+
+int
+scm_is_string (SCM obj)
+{
+ return IS_STRING (obj);
+}
+
+SCM
+scm_from_locale_stringn (const char *str, size_t len)
+{
+ SCM res;
+ char *dst;
+
+ if (len == (size_t)-1)
+ len = strlen (str);
+ res = scm_i_make_string (len, &dst);
+ memcpy (dst, str, len);
+ return res;
+}
+
+SCM
+scm_from_locale_string (const char *str)
+{
+ return scm_from_locale_stringn (str, -1);
+}
+
+SCM
+scm_take_locale_stringn (char *str, size_t len)
+{
+ SCM buf, res;
+
+ if (len == (size_t)-1)
+ len = strlen (str);
+ else
+ {
+ /* Ensure STR is null terminated. A realloc for 1 extra byte should
+ often be satisfied from the alignment padding after the block, with
+ no actual data movement. */
+ str = scm_realloc (str, len+1);
+ str[len] = '\0';
+ }
+
+ buf = scm_i_take_stringbufn (str, len);
+ res = scm_double_cell (STRING_TAG,
+ SCM_UNPACK (buf),
+ (scm_t_bits) 0, (scm_t_bits) len);
+ return res;
+}
+
+SCM
+scm_take_locale_string (char *str)
+{
+ return scm_take_locale_stringn (str, -1);
+}
+
+char *
+scm_to_locale_stringn (SCM str, size_t *lenp)
+{
+ char *res;
+ size_t len;
+
+ if (!scm_is_string (str))
+ scm_wrong_type_arg_msg (NULL, 0, str, "string");
+ len = scm_i_string_length (str);
+ res = scm_malloc (len + ((lenp==NULL)? 1 : 0));
+ memcpy (res, scm_i_string_chars (str), len);
+ if (lenp == NULL)
+ {
+ res[len] = '\0';
+ if (strlen (res) != len)
+ {
+ free (res);
+ scm_misc_error (NULL,
+ "string contains #\\nul character: ~S",
+ scm_list_1 (str));
+ }
+ }
+ else
+ *lenp = len;
+
+ scm_remember_upto_here_1 (str);
+ return res;
+}
+
+char *
+scm_to_locale_string (SCM str)
+{
+ return scm_to_locale_stringn (str, NULL);
+}
+
+size_t
+scm_to_locale_stringbuf (SCM str, char *buf, size_t max_len)
+{
+ size_t len;
+
+ if (!scm_is_string (str))
+ scm_wrong_type_arg_msg (NULL, 0, str, "string");
+ len = scm_i_string_length (str);
+ memcpy (buf, scm_i_string_chars (str), (len > max_len)? max_len : len);
+ scm_remember_upto_here_1 (str);
+ return len;
+}
+
+/* converts C scm_array of strings to SCM scm_list of strings. */
+/* If argc < 0, a null terminated scm_array is assumed. */
+SCM
+scm_makfromstrs (int argc, char **argv)
+{
+ int i = argc;
+ SCM lst = SCM_EOL;
+ if (0 > i)
+ for (i = 0; argv[i]; i++);
+ while (i--)
+ lst = scm_cons (scm_from_locale_string (argv[i]), lst);
+ return lst;
+}
+
+/* Return a newly allocated array of char pointers to each of the strings
+ in args, with a terminating NULL pointer. */
+
+char **
+scm_i_allocate_string_pointers (SCM list)
+{
+ char **result;
+ int len = scm_ilength (list);
+ int i;
+
+ if (len < 0)
+ scm_wrong_type_arg_msg (NULL, 0, list, "proper list");
+
+ scm_dynwind_begin (0);
+
+ result = (char **) scm_malloc ((len + 1) * sizeof (char *));
+ result[len] = NULL;
+ scm_dynwind_unwind_handler (free, result, 0);
+
+ /* The list might be have been modified in another thread, so
+ we check LIST before each access.
+ */
+ for (i = 0; i < len && scm_is_pair (list); i++)
+ {
+ result[i] = scm_to_locale_string (SCM_CAR (list));
+ list = SCM_CDR (list);
+ }
+
+ scm_dynwind_end ();
+ return result;
+}
+
+void
+scm_i_free_string_pointers (char **pointers)
+{
+ int i;
+
+ for (i = 0; pointers[i]; i++)
+ free (pointers[i]);
+ free (pointers);
+}
+
+void
+scm_i_get_substring_spec (size_t len,
+ SCM start, size_t *cstart,
+ SCM end, size_t *cend)
+{
+ if (SCM_UNBNDP (start))
+ *cstart = 0;
+ else
+ *cstart = scm_to_unsigned_integer (start, 0, len);
+
+ if (SCM_UNBNDP (end))
+ *cend = len;
+ else
+ *cend = scm_to_unsigned_integer (end, *cstart, len);
+}
+
+#if SCM_ENABLE_DEPRECATED
+
+/* When these definitions are removed, it becomes reasonable to use
+ read-only strings for string literals. For that, change the reader
+ to create string literals with scm_c_substring_read_only instead of
+ with scm_c_substring_copy.
+*/
+
+int
+scm_i_deprecated_stringp (SCM str)
+{
+ scm_c_issue_deprecation_warning
+ ("SCM_STRINGP is deprecated. Use scm_is_string instead.");
+
+ return scm_is_string (str);
+}
+
+char *
+scm_i_deprecated_string_chars (SCM str)
+{
+ char *chars;
+
+ scm_c_issue_deprecation_warning
+ ("SCM_STRING_CHARS is deprecated. See the manual for alternatives.");
+
+ /* We don't accept shared substrings here since they are not
+ null-terminated.
+ */
+ if (IS_SH_STRING (str))
+ scm_misc_error (NULL,
+ "SCM_STRING_CHARS does not work with shared substrings.",
+ SCM_EOL);
+
+ /* We explicitly test for read-only strings to produce a better
+ error message.
+ */
+
+ if (IS_RO_STRING (str))
+ scm_misc_error (NULL,
+ "SCM_STRING_CHARS does not work with read-only strings.",
+ SCM_EOL);
+
+ /* The following is still wrong, of course...
+ */
+ chars = scm_i_string_writable_chars (str);
+ scm_i_string_stop_writing ();
+ return chars;
+}
+
+size_t
+scm_i_deprecated_string_length (SCM str)
+{
+ scm_c_issue_deprecation_warning
+ ("SCM_STRING_LENGTH is deprecated. Use scm_c_string_length instead.");
+ return scm_c_string_length (str);
+}
+
+#endif
+
+void
+scm_init_strings ()
+{
+ scm_nullstr = scm_i_make_string (0, NULL);
+
+#include "libguile/strings.x"
+}
+
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/