6 /* Copyright (C) 1995,1996,1997,1998,2000,2001, 2004, 2005, 2006 Free Software Foundation, Inc.
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 #include "libguile/__scm.h"
29 /* String representation.
31 A string is a piece of a stringbuf. A stringbuf can be used by
32 more than one string. When a string is written to and the
33 stringbuf of that string is used by more than one string, a new
34 stringbuf is created. That is, strings are copy-on-write. This
35 behavior can be used to make the substring operation quite
38 The implementation is tuned so that mutating a string is costly,
39 but just reading it is cheap and lock-free.
41 There are also mutation-sharing strings. They refer to a part of
42 an ordinary string. Writing to a mutation-sharing string just
43 writes to the ordinary string.
46 Internal, low level interface to the character arrays
48 - Use scm_i_string_chars to get a pointer to the byte array of a
49 string for reading. Use scm_i_string_length to get the number of
50 bytes in that array. The array is not null-terminated.
52 - The array is valid as long as the corresponding SCM object is
53 protected but only until the next SCM_TICK. During such a 'safe
54 point', strings might change their representation.
56 - Use scm_i_string_writable_chars to get the same pointer as with
57 scm_i_string_chars, but for reading and writing. This is a
58 potentially costly operation since it implements the
59 copy-on-write behavior. When done with the writing, call
60 scm_i_string_stop_writing. You must do this before the next
61 SCM_TICK. (This means, before calling almost any other scm_
62 function and you can't allow throws, of course.)
64 - New strings can be created with scm_i_make_string. This gives
65 access to a writable pointer that remains valid as long as nobody
66 else makes a copy-on-write substring of the string. Do not call
67 scm_i_string_stop_writing for this pointer.
71 - SCM_STRINGP is just scm_is_string.
73 - SCM_STRING_CHARS uses scm_i_string_writable_chars and immediately
74 calls scm_i_stop_writing, hoping for the best. SCM_STRING_LENGTH
75 is the same as scm_i_string_length. SCM_STRING_CHARS will throw
76 an error for for strings that are not null-terminated.
79 SCM_API SCM scm_string_p (SCM x);
80 SCM_API SCM scm_string (SCM chrs);
81 SCM_API SCM scm_make_string (SCM k, SCM chr);
82 SCM_API SCM scm_string_length (SCM str);
83 SCM_API SCM scm_string_ref (SCM str, SCM k);
84 SCM_API SCM scm_string_set_x (SCM str, SCM k, SCM chr);
85 SCM_API SCM scm_substring (SCM str, SCM start, SCM end);
86 SCM_API SCM scm_substring_read_only (SCM str, SCM start, SCM end);
87 SCM_API SCM scm_substring_shared (SCM str, SCM start, SCM end);
88 SCM_API SCM scm_substring_copy (SCM str, SCM start, SCM end);
89 SCM_API SCM scm_string_append (SCM args);
91 SCM_API SCM scm_c_make_string (size_t len, SCM chr);
92 SCM_API size_t scm_c_string_length (SCM str);
93 SCM_API size_t scm_c_symbol_length (SCM sym);
94 SCM_API SCM scm_c_string_ref (SCM str, size_t pos);
95 SCM_API void scm_c_string_set_x (SCM str, size_t pos, SCM chr);
96 SCM_API SCM scm_c_substring (SCM str, size_t start, size_t end);
97 SCM_API SCM scm_c_substring_read_only (SCM str, size_t start, size_t end);
98 SCM_API SCM scm_c_substring_shared (SCM str, size_t start, size_t end);
99 SCM_API SCM scm_c_substring_copy (SCM str, size_t start, size_t end);
101 SCM_API int scm_is_string (SCM x);
102 SCM_API SCM scm_from_locale_string (const char *str);
103 SCM_API SCM scm_from_locale_stringn (const char *str, size_t len);
104 SCM_API SCM scm_take_locale_string (char *str);
105 SCM_API SCM scm_take_locale_stringn (char *str, size_t len);
106 SCM_API char *scm_to_locale_string (SCM str);
107 SCM_API char *scm_to_locale_stringn (SCM str, size_t *lenp);
108 SCM_API size_t scm_to_locale_stringbuf (SCM str, char *buf, size_t max_len);
110 SCM_API SCM scm_makfromstrs (int argc, char **argv);
112 /* internal accessor functions. Arguments must be valid. */
114 SCM_API SCM scm_i_make_string (size_t len, char **datap);
115 SCM_API SCM scm_i_substring (SCM str, size_t start, size_t end);
116 SCM_API SCM scm_i_substring_read_only (SCM str, size_t start, size_t end);
117 SCM_API SCM scm_i_substring_shared (SCM str, size_t start, size_t end);
118 SCM_API SCM scm_i_substring_copy (SCM str, size_t start, size_t end);
119 SCM_API size_t scm_i_string_length (SCM str);
120 SCM_API const char *scm_i_string_chars (SCM str);
121 SCM_API char *scm_i_string_writable_chars (SCM str);
122 SCM_API void scm_i_string_stop_writing (void);
124 /* internal functions related to symbols. */
126 SCM_API SCM scm_i_make_symbol (SCM name, scm_t_bits flags,
127 unsigned long hash, SCM props);
129 scm_i_c_make_symbol (const char *name, size_t len,
130 scm_t_bits flags, unsigned long hash, SCM props);
132 scm_i_c_take_symbol (char *name, size_t len,
133 scm_t_bits flags, unsigned long hash, SCM props);
134 SCM_API const char *scm_i_symbol_chars (SCM sym);
135 SCM_API size_t scm_i_symbol_length (SCM sym);
136 SCM_API SCM scm_i_symbol_substring (SCM sym, size_t start, size_t end);
138 /* internal GC functions. */
140 SCM_API SCM scm_i_string_mark (SCM str);
141 SCM_API SCM scm_i_stringbuf_mark (SCM buf);
142 SCM_API SCM scm_i_symbol_mark (SCM buf);
143 SCM_API void scm_i_string_free (SCM str);
144 SCM_API void scm_i_stringbuf_free (SCM buf);
145 SCM_API void scm_i_symbol_free (SCM sym);
147 /* internal utility functions. */
149 SCM_API char **scm_i_allocate_string_pointers (SCM list);
150 SCM_API void scm_i_free_string_pointers (char **pointers);
151 SCM_API void scm_i_get_substring_spec (size_t len,
152 SCM start, size_t *cstart,
153 SCM end, size_t *cend);
154 SCM_API SCM scm_i_take_stringbufn (char *str, size_t len);
156 /* deprecated stuff */
158 #if SCM_ENABLE_DEPRECATED
160 SCM_API int scm_i_deprecated_stringp (SCM obj);
161 SCM_API char *scm_i_deprecated_string_chars (SCM str);
162 SCM_API size_t scm_i_deprecated_string_length (SCM str);
164 #define SCM_STRINGP(x) scm_i_deprecated_stringp(x)
165 #define SCM_STRING_CHARS(x) scm_i_deprecated_string_chars(x)
166 #define SCM_STRING_LENGTH(x) scm_i_deprecated_string_length(x)
167 #define SCM_STRING_UCHARS(str) ((unsigned char *)SCM_STRING_CHARS (str))
171 SCM_API void scm_init_strings (void);
173 #endif /* SCM_STRINGS_H */