1 /* Copyright (C) 1995,1996,1998,2000,2001, 2006, 2008 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 License
5 * as published by the Free Software Foundation; either version 3 of
6 * the License, or (at your option) any later version.
8 * This library is distributed in the hope that it will be useful, but
9 * 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., 51 Franklin Street, Fifth Floor, Boston, MA
24 #include "libguile/_scm.h"
25 #include "libguile/mallocs.h"
26 #include "libguile/strings.h"
27 #include "libguile/lang.h"
29 #include "libguile/options.h"
34 * This is the basic interface for low-level configuration of the
35 * Guile library. It is used for configuring the reader, evaluator,
36 * printer and debugger.
40 * 1. Altering option settings can have side effects.
41 * 2. Option values can be stored in native format.
42 * (Important for efficiency in, e. g., the evaluator.)
43 * 3. Doesn't use up name space.
44 * 4. Options can be naturally grouped => ease of use.
47 /* scm_options is the core of all options interface procedures.
51 * Run time options in Guile are arranged in groups. Each group
52 * affects a certain aspect of the behaviour of the library.
54 * An "options interface procedure" manages one group of options. It
55 * can be used to check or set options, or to get documentation for
56 * all options of a group. The options interface procedure is not
57 * intended to be called directly by the user. The user should
61 * (<group>-options 'help)
62 * (<group>-options 'full)
64 * to display current option settings (The second version also
65 * displays documentation. The third version also displays
66 * information about programmer's options.), and
68 * (<group>-enable '<option-symbol>)
69 * (<group>-disable '<option-symbol>)
70 * (<group>-set! <option-symbol> <value>)
71 * (<group>-options <option setting>)
73 * to alter the state of an option (The last version sets all
74 * options according to <option setting>.) where <group> is the name
75 * of the option group.
77 * An "option setting" represents the state of all low-level options
78 * managed by one options interface procedure. It is a list of
79 * single symbols and symbols followed by a value.
81 * For boolean options, the presence of the symbol of that option in
82 * the option setting indicates a true value. If the symbol isn't a
83 * member of the option setting this represents a false value.
85 * Other options are represented by a symbol followed by the value.
87 * If scm_options is called without arguments, the current option
88 * setting is returned. If the argument is an option setting, options
89 * are altered and the old setting is returned. If the argument isn't
90 * a list, a list of sublists is returned, where each sublist contains
91 * option name, value and documentation string.
94 SCM_SYMBOL (scm_yes_sym
, "yes");
95 SCM_SYMBOL (scm_no_sym
, "no");
97 static SCM protected_objects
= SCM_EOL
;
99 /* Return a list of the current option setting. The format of an
100 * option setting is described in the above documentation. */
102 get_option_setting (const scm_t_option options
[])
106 for (i
= 0; options
[i
].name
; ++i
)
108 switch (options
[i
].type
)
110 case SCM_OPTION_BOOLEAN
:
112 ls
= scm_cons (SCM_PACK (options
[i
].name
), ls
);
114 case SCM_OPTION_INTEGER
:
115 ls
= scm_cons (scm_from_unsigned_integer (options
[i
].val
), ls
);
116 ls
= scm_cons (SCM_PACK (options
[i
].name
), ls
);
119 ls
= scm_cons (SCM_PACK (options
[i
].val
), ls
);
120 ls
= scm_cons (SCM_PACK (options
[i
].name
), ls
);
127 /* Return a list of sublists, where each sublist contains option name, value
128 * and documentation string. */
130 get_documented_option_setting (const scm_t_option options
[])
135 for (i
= 0; options
[i
].name
; ++i
)
137 SCM ls
= scm_cons (scm_from_locale_string (options
[i
].doc
), SCM_EOL
);
138 switch (options
[i
].type
)
140 case SCM_OPTION_BOOLEAN
:
141 ls
= scm_cons (options
[i
].val
? scm_yes_sym
: scm_no_sym
, ls
);
143 case SCM_OPTION_INTEGER
:
144 ls
= scm_cons (scm_from_unsigned_integer (options
[i
].val
), ls
);
147 ls
= scm_cons (SCM_PACK (options
[i
].val
), ls
);
149 ls
= scm_cons (SCM_PACK (options
[i
].name
), ls
);
150 ans
= scm_cons (ls
, ans
);
157 options_length (scm_t_option options
[])
160 for (; options
[i
].name
!= NULL
; ++i
)
166 /* Alters options according to the given option setting 'args'. The value of
167 * args is known to be a list, but it is not known whether the list is a well
168 * formed option setting, i. e. if for every non-boolean option a value is
169 * given. For this reason, the function applies all changes to a copy of the
170 * original setting in memory. Only if 'args' was successfully processed,
171 * the new setting will overwrite the old one.
173 * If DRY_RUN is set, don't change anything. This is useful for trying out an option
174 * before entering a critical section.
177 change_option_setting (SCM args
, scm_t_option options
[], const char *s
,
181 SCM locally_protected_args
= args
;
182 SCM malloc_obj
= scm_malloc_obj (options_length (options
) * sizeof (scm_t_bits
));
183 scm_t_bits
*flags
= (scm_t_bits
*) SCM_MALLOCDATA (malloc_obj
);
185 for (i
= 0; options
[i
].name
; ++i
)
187 if (options
[i
].type
== SCM_OPTION_BOOLEAN
)
190 flags
[i
] = options
[i
].val
;
193 while (!SCM_NULL_OR_NIL_P (args
))
195 SCM name
= SCM_CAR (args
);
198 for (i
= 0; options
[i
].name
&& !found
; ++i
)
200 if (scm_is_eq (name
, SCM_PACK (options
[i
].name
)))
202 switch (options
[i
].type
)
204 case SCM_OPTION_BOOLEAN
:
207 case SCM_OPTION_INTEGER
:
208 args
= SCM_CDR (args
);
209 flags
[i
] = scm_to_size_t (scm_car (args
));
212 args
= SCM_CDR (args
);
213 flags
[i
] = SCM_UNPACK (scm_car (args
));
221 scm_misc_error (s
, "Unknown option name: ~S", scm_list_1 (name
));
223 args
= SCM_CDR (args
);
229 for (i
= 0; options
[i
].name
; ++i
)
231 if (options
[i
].type
== SCM_OPTION_SCM
)
233 SCM old
= SCM_PACK (options
[i
].val
);
234 SCM
new = SCM_PACK (flags
[i
]);
236 protected_objects
= scm_delq1_x (old
, protected_objects
);
238 protected_objects
= scm_cons (new, protected_objects
);
240 options
[i
].val
= flags
[i
];
243 scm_remember_upto_here_2 (locally_protected_args
, malloc_obj
);
248 scm_options (SCM args
, scm_t_option options
[], const char *s
)
250 return scm_options_try (args
, options
, s
, 0);
254 scm_options_try (SCM args
, scm_t_option options
[], const char *s
,
257 if (SCM_UNBNDP (args
))
258 return get_option_setting (options
);
259 else if (!SCM_NULL_OR_NIL_P (args
) && !scm_is_pair (args
))
260 /* Dirk:FIXME:: This criterion should be improved. IMO it is better to
261 * demand that args is #t if documentation should be shown than to say
262 * that every argument except a list will print out documentation. */
263 return get_documented_option_setting (options
);
267 SCM_ASSERT (scm_is_true (scm_list_p (args
)), args
, 1, s
);
268 old_setting
= get_option_setting (options
);
269 change_option_setting (args
, options
, s
, dry_run
);
276 scm_init_opts (SCM (*func
) (SCM
), scm_t_option options
[])
280 for (i
= 0; options
[i
].name
; ++i
)
282 SCM name
= scm_from_locale_symbol (options
[i
].name
);
283 options
[i
].name
= (char *) SCM_UNPACK (name
);
284 scm_permanent_object (name
);
286 func (SCM_UNDEFINED
);
293 scm_gc_register_root (&protected_objects
);
295 #include "libguile/options.x"