#ifndef SCM_STRINGS_H
#define SCM_STRINGS_H
-/* Copyright (C) 1995,1996,1997,1998,2000,2001 Free Software Foundation, Inc.
+/* Copyright (C) 1995,1996,1997,1998,2000,2001, 2004, 2005 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
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
\f
\f
-#define SCM_STRING_MAX_LENGTH ((SCM_T_BITS_MAX-255)/256)
+/* String representation.
-#define SCM_I_MAKE_STRING_TAG(l) ((((scm_t_bits) (l)) << 8) + scm_tc7_string)
-#define SCM_I_STRINGP(x) (!SCM_IMP (x) && (SCM_TYP7 (x) == scm_tc7_string))
-#define SCM_I_STRING_UCHARS(x) ((unsigned char *) (SCM_CELL_WORD_1 (x)))
-#define SCM_I_STRING_CHARS(x) ((char *) (SCM_CELL_WORD_1 (x)))
-#define SCM_I_STRING_LENGTH(x) ((size_t) (SCM_CELL_WORD_0 (x) >> 8))
+ A string is a piece of a stringbuf. A stringbuf can be used by
+ more than one string. When a string is written to and the
+ stringbuf of that string is used by more than one string, a new
+ stringbuf is created. That is, strings are copy-on-write. This
+ behavior can be used to make the substring operation quite
+ efficient.
-#define SCM_STRINGP SCM_I_STRINGP
-#define SCM_STRING_CHARS SCM_I_STRING_CHARS
-#define SCM_STRING_UCHARS SCM_I_STRING_UCHARS
-#define SCM_STRING_LENGTH SCM_I_STRING_LENGTH
+ The implementation is tuned so that mutating a string is costly,
+ but just reading it is cheap and lock-free.
-\f
+ There are also mutation-sharing strings. They refer to a part of
+ an ordinary string. Writing to a mutation-sharing string just
+ writes to the ordinary string.
+
+
+ Internal, low level interface to the character arrays
+
+ - Use scm_i_string_chars to get a pointer to the byte array of a
+ string for reading. Use scm_i_string_length to get the number of
+ bytes in that array. The array is not null-terminated.
+
+ - The array is valid as long as the corresponding SCM object is
+ protected but only until the next SCM_TICK. During such a 'safe
+ point', strings might change their representation.
+
+ - Use scm_i_string_writable_chars to get the same pointer as with
+ scm_i_string_chars, but for reading and writing. This is a
+ potentially costly operation since it implements the
+ copy-on-write behavior. When done with the writing, call
+ scm_i_string_stop_writing. You must do this before the next
+ SCM_TICK. (This means, before calling almost any other scm_
+ function and you can't allow throws, of course.)
+
+ - New strings can be created with scm_i_make_string. This gives
+ access to a writable pointer that remains valid as long as nobody
+ else makes a copy-on-write substring of the string. Do not call
+ scm_i_string_stop_writing for this pointer.
+
+ Legacy interface
+
+ - SCM_STRINGP is just scm_is_string.
+
+ - SCM_STRING_CHARS uses scm_i_string_writable_chars and immediately
+ calls scm_i_stop_writing, hoping for the best. SCM_STRING_LENGTH
+ is the same as scm_i_string_length. SCM_STRING_CHARS will throw
+ an error for for strings that are not null-terminated.
+*/
SCM_API SCM scm_string_p (SCM x);
SCM_API SCM scm_string (SCM chrs);
SCM_API SCM scm_string_ref (SCM str, SCM k);
SCM_API SCM scm_string_set_x (SCM str, SCM k, SCM chr);
SCM_API SCM scm_substring (SCM str, SCM start, SCM end);
+SCM_API SCM scm_substring_read_only (SCM str, SCM start, SCM end);
+SCM_API SCM scm_substring_shared (SCM str, SCM start, SCM end);
+SCM_API SCM scm_substring_copy (SCM str, SCM start, SCM end);
SCM_API SCM scm_string_append (SCM args);
-SCM_API SCM scm_makfromstrs (int argc, char **argv);
-SCM_API SCM scm_take_str (char *s, size_t len);
-SCM_API SCM scm_take0str (char *s);
-SCM_API SCM scm_mem2string (const char *src, size_t len);
-SCM_API SCM scm_str2string (const char *src);
-SCM_API SCM scm_makfrom0str (const char *src);
-SCM_API SCM scm_makfrom0str_opt (const char *src);
-SCM_API SCM scm_allocate_string (size_t len);
+SCM_API SCM scm_c_make_string (size_t len, SCM chr);
+SCM_API size_t scm_c_string_length (SCM str);
+SCM_API SCM scm_c_string_ref (SCM str, size_t pos);
+SCM_API void scm_c_string_set_x (SCM str, size_t pos, SCM chr);
+SCM_API SCM scm_c_substring (SCM str, size_t start, size_t end);
+SCM_API SCM scm_c_substring_read_only (SCM str, size_t start, size_t end);
+SCM_API SCM scm_c_substring_shared (SCM str, size_t start, size_t end);
+SCM_API SCM scm_c_substring_copy (SCM str, size_t start, size_t end);
SCM_API int scm_is_string (SCM x);
SCM_API SCM scm_from_locale_string (const char *str);
SCM_API char *scm_to_locale_stringn (SCM str, size_t *lenp);
SCM_API size_t scm_to_locale_stringbuf (SCM str, char *buf, size_t max_len);
+SCM_API SCM scm_makfromstrs (int argc, char **argv);
+
+/* internal accessor functions. Arguments must be valid. */
+
+SCM_API SCM scm_i_make_string (size_t len, char **datap);
+SCM_API SCM scm_i_substring (SCM str, size_t start, size_t end);
+SCM_API SCM scm_i_substring_read_only (SCM str, size_t start, size_t end);
+SCM_API SCM scm_i_substring_shared (SCM str, size_t start, size_t end);
+SCM_API SCM scm_i_substring_copy (SCM str, size_t start, size_t end);
+SCM_API size_t scm_i_string_length (SCM str);
+SCM_API const char *scm_i_string_chars (SCM str);
+SCM_API char *scm_i_string_writable_chars (SCM str);
+SCM_API void scm_i_string_stop_writing (void);
+
+/* internal functions related to symbols. */
+
+SCM_API SCM scm_i_make_symbol (SCM name, scm_t_bits flags,
+ unsigned long hash, SCM props);
+SCM_API SCM
+scm_i_c_make_symbol (const char *name, size_t len,
+ scm_t_bits flags, unsigned long hash, SCM props);
+SCM_API SCM
+scm_i_c_take_symbol (char *name, size_t len,
+ scm_t_bits flags, unsigned long hash, SCM props);
+SCM_API const char *scm_i_symbol_chars (SCM sym);
+SCM_API size_t scm_i_symbol_length (SCM sym);
+SCM_API SCM scm_i_symbol_substring (SCM sym, size_t start, size_t end);
+
+/* internal GC functions. */
+
+SCM_API SCM scm_i_string_mark (SCM str);
+SCM_API SCM scm_i_stringbuf_mark (SCM buf);
+SCM_API SCM scm_i_symbol_mark (SCM buf);
+SCM_API void scm_i_string_free (SCM str);
+SCM_API void scm_i_stringbuf_free (SCM buf);
+SCM_API void scm_i_symbol_free (SCM sym);
+
/* internal utility functions. */
SCM_API char **scm_i_allocate_string_pointers (SCM list);
SCM_API void scm_i_free_string_pointers (char **pointers);
+SCM_API void scm_i_get_substring_spec (size_t len,
+ SCM start, size_t *cstart,
+ SCM end, size_t *cend);
+SCM_API SCM scm_i_take_stringbufn (char *str, size_t len);
+
+/* deprecated stuff */
+
+#if SCM_ENABLE_DEPRECATED
+
+SCM_API int scm_i_deprecated_stringp (SCM obj);
+SCM_API char *scm_i_deprecated_string_chars (SCM str);
+SCM_API size_t scm_i_deprecated_string_length (SCM str);
+
+#define SCM_STRINGP(x) scm_i_deprecated_stringp(x)
+#define SCM_STRING_CHARS(x) scm_i_deprecated_string_chars(x)
+#define SCM_STRING_LENGTH(x) scm_i_deprecated_string_length(x)
+#define SCM_STRING_UCHARS(str) ((unsigned char *)SCM_STRING_CHARS (str))
+
+#endif
SCM_API void scm_init_strings (void);
HCoop / bpt / guile.git / blobdiff