1 /* Copyright (C) 1995,1996,1998,2000,2001 Free Software Foundation
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public
5 * License as published by the Free Software Foundation; either
6 * version 2.1 of the License, or (at your option) any later version.
8 * This library is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * Lesser General Public License for more details.
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 #include "libguile/_scm.h"
21 #include "libguile/mallocs.h"
22 #include "libguile/strings.h"
23 #include "libguile/lang.h"
25 #include "libguile/options.h"
30 * This is the basic interface for low-level configuration of the
31 * Guile library. It is used for configuring the reader, evaluator,
32 * printer and debugger.
36 * 1. Altering option settings can have side effects.
37 * 2. Option values can be stored in native format.
38 * (Important for efficiency in, e. g., the evaluator.)
39 * 3. Doesn't use up name space.
40 * 4. Options can be naturally grouped => ease of use.
43 /* scm_options is the core of all options interface procedures.
47 * Run time options in Guile are arranged in groups. Each group
48 * affects a certain aspect of the behaviour of the library.
50 * An "options interface procedure" manages one group of options. It
51 * can be used to check or set options, or to get documentation for
52 * all options of a group. The options interface procedure is not
53 * intended to be called directly by the user. The user should
57 * (<group>-options 'help)
58 * (<group>-options 'full)
60 * to display current option settings (The second version also
61 * displays documentation. The third version also displays
62 * information about programmer's options.), and
64 * (<group>-enable '<option-symbol>)
65 * (<group>-disable '<option-symbol>)
66 * (<group>-set! <option-symbol> <value>)
67 * (<group>-options <option setting>)
69 * to alter the state of an option (The last version sets all
70 * options according to <option setting>.) where <group> is the name
71 * of the option group.
73 * An "option setting" represents the state of all low-level options
74 * managed by one options interface procedure. It is a list of
75 * single symbols and symbols followed by a value.
77 * For boolean options, the presence of the symbol of that option in
78 * the option setting indicates a true value. If the symbol isn't a
79 * member of the option setting this represents a false value.
81 * Other options are represented by a symbol followed by the value.
83 * If scm_options is called without arguments, the current option
84 * setting is returned. If the argument is an option setting, options
85 * are altered and the old setting is returned. If the argument isn't
86 * a list, a list of sublists is returned, where each sublist contains
87 * option name, value and documentation string.
90 SCM_SYMBOL (scm_yes_sym
, "yes");
91 SCM_SYMBOL (scm_no_sym
, "no");
93 static SCM protected_objects
= SCM_EOL
;
95 /* Return a list of the current option setting. The format of an
96 * option setting is described in the above documentation. */
98 get_option_setting (const scm_t_option options
[], unsigned int n
)
102 for (i
= 0; i
!= n
; ++i
)
104 switch (options
[i
].type
)
106 case SCM_OPTION_BOOLEAN
:
108 ls
= scm_cons (SCM_PACK (options
[i
].name
), ls
);
110 case SCM_OPTION_INTEGER
:
111 ls
= scm_cons (scm_from_unsigned_integer (options
[i
].val
), ls
);
112 ls
= scm_cons (SCM_PACK (options
[i
].name
), ls
);
115 ls
= scm_cons (SCM_PACK (options
[i
].val
), ls
);
116 ls
= scm_cons (SCM_PACK (options
[i
].name
), ls
);
123 /* Return a list of sublists, where each sublist contains option name, value
124 * and documentation string. */
126 get_documented_option_setting (const scm_t_option options
[], unsigned int n
)
131 for (i
= 0; i
!= n
; ++i
)
133 SCM ls
= scm_cons (scm_from_locale_string (options
[i
].doc
), SCM_EOL
);
134 switch (options
[i
].type
)
136 case SCM_OPTION_BOOLEAN
:
137 ls
= scm_cons (options
[i
].val
? scm_yes_sym
: scm_no_sym
, ls
);
139 case SCM_OPTION_INTEGER
:
140 ls
= scm_cons (scm_from_unsigned_integer (options
[i
].val
), ls
);
143 ls
= scm_cons (SCM_PACK (options
[i
].val
), ls
);
145 ls
= scm_cons (SCM_PACK (options
[i
].name
), ls
);
146 ans
= scm_cons (ls
, ans
);
152 /* Alters options according to the given option setting 'args'. The value of
153 * args is known to be a list, but it is not known whether the list is a well
154 * formed option setting, i. e. if for every non-boolean option a value is
155 * given. For this reason, the function applies all changes to a copy of the
156 * original setting in memory. Only if 'args' was successfully processed,
157 * the new setting will overwrite the old one. */
159 change_option_setting (SCM args
, scm_t_option options
[], unsigned int n
, const char *s
)
162 SCM locally_protected_args
= args
;
163 SCM malloc_obj
= scm_malloc_obj (n
* sizeof (scm_t_bits
));
164 scm_t_bits
*flags
= (scm_t_bits
*) SCM_MALLOCDATA (malloc_obj
);
166 for (i
= 0; i
!= n
; ++i
)
168 if (options
[i
].type
== SCM_OPTION_BOOLEAN
)
171 flags
[i
] = options
[i
].val
;
174 while (!SCM_NULL_OR_NIL_P (args
))
176 SCM name
= SCM_CAR (args
);
179 for (i
= 0; i
!= n
&& !found
; ++i
)
181 if (scm_is_eq (name
, SCM_PACK (options
[i
].name
)))
183 switch (options
[i
].type
)
185 case SCM_OPTION_BOOLEAN
:
188 case SCM_OPTION_INTEGER
:
189 args
= SCM_CDR (args
);
190 flags
[i
] = scm_to_size_t (scm_car (args
));
193 args
= SCM_CDR (args
);
194 flags
[i
] = SCM_UNPACK (scm_car (args
));
202 scm_misc_error (s
, "Unknown option name: ~S", scm_list_1 (name
));
204 args
= SCM_CDR (args
);
207 for (i
= 0; i
!= n
; ++i
)
209 if (options
[i
].type
== SCM_OPTION_SCM
)
211 SCM old
= SCM_PACK (options
[i
].val
);
212 SCM
new = SCM_PACK (flags
[i
]);
214 protected_objects
= scm_delq1_x (old
, protected_objects
);
216 protected_objects
= scm_cons (new, protected_objects
);
218 options
[i
].val
= flags
[i
];
221 scm_remember_upto_here_2 (locally_protected_args
, malloc_obj
);
226 scm_options (SCM args
, scm_t_option options
[], unsigned int n
, const char *s
)
228 if (SCM_UNBNDP (args
))
229 return get_option_setting (options
, n
);
230 else if (!SCM_NULL_OR_NIL_P (args
) && !scm_is_pair (args
))
231 /* Dirk:FIXME:: This criterion should be improved. IMO it is better to
232 * demand that args is #t if documentation should be shown than to say
233 * that every argument except a list will print out documentation. */
234 return get_documented_option_setting (options
, n
);
238 SCM_ASSERT (scm_is_true (scm_list_p (args
)), args
, 1, s
);
239 old_setting
= get_option_setting (options
, n
);
240 change_option_setting (args
, options
, n
, s
);
247 scm_init_opts (SCM (*func
) (SCM
), scm_t_option options
[], unsigned int n
)
251 for (i
= 0; i
!= n
; ++i
)
253 SCM name
= scm_from_locale_symbol (options
[i
].name
);
254 options
[i
].name
= (char *) SCM_UNPACK (name
);
255 scm_permanent_object (name
);
257 func (SCM_UNDEFINED
);
264 scm_gc_register_root (&protected_objects
);
266 #include "libguile/options.x"