6 /* Copyright (C) 1995,1996,1997,1998,2000,2001, 2004, 2005, 2006, 2008, 2009 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 License
10 * as published by the Free Software Foundation; either version 3 of
11 * the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful, but
14 * 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
26 #include "libguile/__scm.h"
30 /* String representation.
32 A string is a piece of a stringbuf. A stringbuf can be used by
33 more than one string. When a string is written to and the
34 stringbuf of that string is used by more than one string, a new
35 stringbuf is created. That is, strings are copy-on-write. This
36 behavior can be used to make the substring operation quite
39 The implementation is tuned so that mutating a string is costly,
40 but just reading it is cheap and lock-free.
42 There are also mutation-sharing strings. They refer to a part of
43 an ordinary string. Writing to a mutation-sharing string just
44 writes to the ordinary string.
47 Internal, low level interface to the character arrays
49 - Use scm_is_narrow_string to determine is the string is narrow or
52 - Use scm_i_string_chars or scm_i_string_wide_chars to get a
53 pointer to the byte or scm_t_wchar array of a string for reading.
54 Use scm_i_string_length to get the number of characters in that
55 array. The array is not null-terminated.
57 - The array is valid as long as the corresponding SCM object is
58 protected but only until the next SCM_TICK. During such a 'safe
59 point', strings might change their representation.
61 - Use scm_i_string_start_writing to get a version of the string
62 ready for reading and writing. This is a potentially costly
63 operation since it implements the copy-on-write behavior. When
64 done with the writing, call scm_i_string_stop_writing. You must
65 do this before the next SCM_TICK. (This means, before calling
66 almost any other scm_ function and you can't allow throws, of
69 - New strings can be created with scm_i_make_string or
70 scm_i_make_wide_string. This gives access to a writable pointer
71 that remains valid as long as nobody else makes a copy-on-write
72 substring of the string. Do not call scm_i_string_stop_writing
75 - Alternately, scm_i_string_ref and scm_i_string_set_x can be used
76 to read and write strings without worrying about whether the
77 string is narrow or wide. scm_i_string_set_x still needs to be
78 bracketed by scm_i_string_start_writing and
79 scm_i_string_stop_writing.
83 - SCM_STRINGP is just scm_is_string.
85 - SCM_STRING_CHARS uses scm_i_string_writable_chars and immediately
86 calls scm_i_stop_writing, hoping for the best. SCM_STRING_LENGTH
87 is the same as scm_i_string_length. SCM_STRING_CHARS will throw
88 an error for for strings that are not null-terminated. There is
89 no wide version of this interface.
92 /* A type indicating what strategy to take when string locale
93 conversion is unsuccessful. */
96 SCM_FAILED_CONVERSION_ERROR
= SCM_ICONVEH_ERROR
,
97 SCM_FAILED_CONVERSION_QUESTION_MARK
= SCM_ICONVEH_QUESTION_MARK
,
98 SCM_FAILED_CONVERSION_ESCAPE_SEQUENCE
= SCM_ICONVEH_ESCAPE_SEQUENCE
99 } scm_t_string_failed_conversion_handler
;
101 SCM_API SCM
scm_string_p (SCM x
);
102 SCM_API SCM
scm_string (SCM chrs
);
103 SCM_API SCM
scm_make_string (SCM k
, SCM chr
);
104 SCM_API SCM
scm_string_length (SCM str
);
105 SCM_API SCM
scm_string_bytes_per_char (SCM str
);
106 SCM_API SCM
scm_string_ref (SCM str
, SCM k
);
107 SCM_API SCM
scm_string_set_x (SCM str
, SCM k
, SCM chr
);
108 SCM_API SCM
scm_substring (SCM str
, SCM start
, SCM end
);
109 SCM_API SCM
scm_substring_read_only (SCM str
, SCM start
, SCM end
);
110 SCM_API SCM
scm_substring_shared (SCM str
, SCM start
, SCM end
);
111 SCM_API SCM
scm_substring_copy (SCM str
, SCM start
, SCM end
);
112 SCM_API SCM
scm_string_append (SCM args
);
114 SCM_API SCM
scm_from_stringn (const char *str
, size_t len
,
115 const char *encoding
,
116 scm_t_string_failed_conversion_handler
118 SCM_API SCM
scm_c_make_string (size_t len
, SCM chr
);
119 SCM_API
size_t scm_c_string_length (SCM str
);
120 SCM_API
size_t scm_c_symbol_length (SCM sym
);
121 SCM_API SCM
scm_c_string_ref (SCM str
, size_t pos
);
122 SCM_API
void scm_c_string_set_x (SCM str
, size_t pos
, SCM chr
);
123 SCM_API SCM
scm_c_substring (SCM str
, size_t start
, size_t end
);
124 SCM_API SCM
scm_c_substring_read_only (SCM str
, size_t start
, size_t end
);
125 SCM_API SCM
scm_c_substring_shared (SCM str
, size_t start
, size_t end
);
126 SCM_API SCM
scm_c_substring_copy (SCM str
, size_t start
, size_t end
);
128 SCM_API
int scm_is_string (SCM x
);
129 SCM_API SCM
scm_from_locale_string (const char *str
);
130 SCM_API SCM
scm_from_locale_stringn (const char *str
, size_t len
);
131 SCM_INTERNAL SCM
scm_i_from_utf8_string (const scm_t_uint8
*str
);
132 SCM_API SCM
scm_take_locale_string (char *str
);
133 SCM_API SCM
scm_take_locale_stringn (char *str
, size_t len
);
134 SCM_API
char *scm_to_locale_string (SCM str
);
135 SCM_API
char *scm_to_locale_stringn (SCM str
, size_t *lenp
);
136 SCM_INTERNAL
char *scm_to_stringn (SCM str
, size_t *lenp
,
137 const char *encoding
,
138 scm_t_string_failed_conversion_handler
140 SCM_INTERNAL scm_t_uint8
*scm_i_to_utf8_string (SCM str
);
141 SCM_API
size_t scm_to_locale_stringbuf (SCM str
, char *buf
, size_t max_len
);
143 SCM_API SCM
scm_makfromstrs (int argc
, char **argv
);
145 /* internal accessor functions. Arguments must be valid. */
147 SCM_INTERNAL SCM
scm_i_make_string (size_t len
, char **datap
);
148 SCM_INTERNAL SCM
scm_i_make_wide_string (size_t len
, scm_t_wchar
**datap
);
149 SCM_INTERNAL SCM
scm_i_substring (SCM str
, size_t start
, size_t end
);
150 SCM_INTERNAL SCM
scm_i_substring_read_only (SCM str
, size_t start
, size_t end
);
151 SCM_INTERNAL SCM
scm_i_substring_shared (SCM str
, size_t start
, size_t end
);
152 SCM_INTERNAL SCM
scm_i_substring_copy (SCM str
, size_t start
, size_t end
);
153 SCM_INTERNAL
size_t scm_i_string_length (SCM str
);
154 SCM_API
/* FIXME: not internal */ const char *scm_i_string_chars (SCM str
);
155 SCM_API
/* FIXME: not internal */ char *scm_i_string_writable_chars (SCM str
);
156 SCM_INTERNAL
const scm_t_wchar
*scm_i_string_wide_chars (SCM str
);
157 SCM_INTERNAL SCM
scm_i_string_start_writing (SCM str
);
158 SCM_INTERNAL
void scm_i_string_stop_writing (void);
159 SCM_INTERNAL
int scm_i_is_narrow_string (SCM str
);
160 SCM_INTERNAL scm_t_wchar
scm_i_string_ref (SCM str
, size_t x
);
161 SCM_INTERNAL
int scm_i_string_contains_char (SCM str
, char c
);
162 SCM_INTERNAL
int scm_i_string_strcmp (SCM sstr
, size_t start_x
, const char *cstr
);
163 SCM_INTERNAL
void scm_i_string_set_x (SCM str
, size_t p
, scm_t_wchar chr
);
164 /* internal functions related to symbols. */
166 SCM_INTERNAL SCM
scm_i_make_symbol (SCM name
, scm_t_bits flags
,
167 unsigned long hash
, SCM props
);
169 scm_i_c_make_symbol (const char *name
, size_t len
,
170 scm_t_bits flags
, unsigned long hash
, SCM props
);
171 SCM_INTERNAL
const char *scm_i_symbol_chars (SCM sym
);
172 SCM_INTERNAL
const scm_t_wchar
*scm_i_symbol_wide_chars (SCM sym
);
173 SCM_INTERNAL
size_t scm_i_symbol_length (SCM sym
);
174 SCM_INTERNAL
int scm_i_is_narrow_symbol (SCM str
);
175 SCM_INTERNAL
int scm_i_try_narrow_string (SCM str
);
176 SCM_INTERNAL SCM
scm_i_symbol_substring (SCM sym
, size_t start
, size_t end
);
177 SCM_INTERNAL scm_t_wchar
scm_i_symbol_ref (SCM sym
, size_t x
);
179 /* internal utility functions. */
181 SCM_INTERNAL
char **scm_i_allocate_string_pointers (SCM list
);
182 SCM_INTERNAL
void scm_i_get_substring_spec (size_t len
,
183 SCM start
, size_t *cstart
,
184 SCM end
, size_t *cend
);
186 /* Debugging functions */
188 SCM_API SCM
scm_sys_string_dump (SCM
);
189 SCM_API SCM
scm_sys_symbol_dump (SCM
);
190 #if SCM_STRING_LENGTH_HISTOGRAM
191 SCM_API SCM
scm_sys_stringbuf_hist (void);
194 /* deprecated stuff */
196 #if SCM_ENABLE_DEPRECATED
198 SCM_API
int scm_i_deprecated_stringp (SCM obj
);
199 SCM_API
char *scm_i_deprecated_string_chars (SCM str
);
200 SCM_API
size_t scm_i_deprecated_string_length (SCM str
);
202 #define SCM_STRINGP(x) scm_i_deprecated_stringp(x)
203 #define SCM_STRING_CHARS(x) scm_i_deprecated_string_chars(x)
204 #define SCM_STRING_LENGTH(x) scm_i_deprecated_string_length(x)
205 #define SCM_STRING_UCHARS(str) ((unsigned char *)SCM_STRING_CHARS (str))
209 SCM_INTERNAL
void scm_init_strings (void);
211 #endif /* SCM_STRINGS_H */