1 /* Copyright (C) 1995,1996,1998,2000,2001, 2006, 2008, 2009, 2010, 2011 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"
28 #include "libguile/options.h"
33 * This is the basic interface for low-level configuration of the
34 * Guile library. It is used for configuring the reader, evaluator,
35 * printer and debugger.
39 * 1. Altering option settings can have side effects.
40 * 2. Option values can be stored in native format.
41 * (Important for efficiency in, e. g., the evaluator.)
42 * 3. Doesn't use up name space.
43 * 4. Options can be naturally grouped => ease of use.
46 /* scm_options is the core of all options interface procedures.
50 * Run time options in Guile are arranged in groups. Each group
51 * affects a certain aspect of the behaviour of the library.
53 * An "options interface procedure" manages one group of options. It
54 * can be used to check or set options, or to get documentation for
55 * all options of a group. The options interface procedure is not
56 * intended to be called directly by the user. The user should
60 * (<group>-options 'help)
61 * (<group>-options 'full)
63 * to display current option settings (The second version also
64 * displays documentation. The third version also displays
65 * information about programmer's options.), and
67 * (<group>-enable '<option-symbol>)
68 * (<group>-disable '<option-symbol>)
69 * (<group>-set! <option-symbol> <value>)
70 * (<group>-options <option setting>)
72 * to alter the state of an option (The last version sets all
73 * options according to <option setting>.) where <group> is the name
74 * of the option group.
76 * An "option setting" represents the state of all low-level options
77 * managed by one options interface procedure. It is a list of
78 * single symbols and symbols followed by a value.
80 * For boolean options, the presence of the symbol of that option in
81 * the option setting indicates a true value. If the symbol isn't a
82 * member of the option setting this represents a false value.
84 * Other options are represented by a symbol followed by the value.
86 * If scm_options is called without arguments, the current option
87 * setting is returned. If the argument is an option setting, options
88 * are altered and the old setting is returned. If the argument isn't
89 * a list, a list of sublists is returned, where each sublist contains
90 * option name, value and documentation string.
93 SCM_SYMBOL (scm_yes_sym
, "yes");
94 SCM_SYMBOL (scm_no_sym
, "no");
96 /* Return a list of the current option setting. The format of an
97 * option setting is described in the above documentation. */
99 get_option_setting (const scm_t_option options
[])
103 for (i
= 0; options
[i
].name
; ++i
)
105 switch (options
[i
].type
)
107 case SCM_OPTION_BOOLEAN
:
109 ls
= scm_cons (SCM_PACK (options
[i
].name
), ls
);
111 case SCM_OPTION_INTEGER
:
112 ls
= scm_cons (scm_from_unsigned_integer (options
[i
].val
), ls
);
113 ls
= scm_cons (SCM_PACK (options
[i
].name
), ls
);
116 ls
= scm_cons (SCM_PACK (options
[i
].val
), ls
);
117 ls
= scm_cons (SCM_PACK (options
[i
].name
), ls
);
124 /* Return a list of sublists, where each sublist contains option name, value
125 * and documentation string. */
127 get_documented_option_setting (const scm_t_option options
[])
132 for (i
= 0; options
[i
].name
; ++i
)
134 SCM ls
= scm_cons (scm_from_utf8_string (options
[i
].doc
), SCM_EOL
);
135 switch (options
[i
].type
)
137 case SCM_OPTION_BOOLEAN
:
138 ls
= scm_cons (options
[i
].val
? scm_yes_sym
: scm_no_sym
, ls
);
140 case SCM_OPTION_INTEGER
:
141 ls
= scm_cons (scm_from_unsigned_integer (options
[i
].val
), ls
);
144 ls
= scm_cons (SCM_PACK (options
[i
].val
), ls
);
146 ls
= scm_cons (SCM_PACK (options
[i
].name
), ls
);
147 ans
= scm_cons (ls
, ans
);
149 return scm_reverse_x (ans
, SCM_UNDEFINED
);
154 options_length (scm_t_option options
[])
157 for (; options
[i
].name
!= NULL
; ++i
)
163 /* Alters options according to the given option setting 'args'. The value of
164 * args is known to be a list, but it is not known whether the list is a well
165 * formed option setting, i. e. if for every non-boolean option a value is
166 * given. For this reason, the function applies all changes to a copy of the
167 * original setting in memory. Only if 'args' was successfully processed,
168 * the new setting will overwrite the old one.
170 * If DRY_RUN is set, don't change anything. This is useful for trying out an option
171 * before entering a critical section.
174 change_option_setting (SCM args
, scm_t_option options
[], const char *s
,
178 scm_t_bits
*new_vals
;
180 new_vals
= scm_gc_malloc (options_length (options
) * sizeof (scm_t_bits
),
183 for (i
= 0; options
[i
].name
; ++i
)
185 if (options
[i
].type
== SCM_OPTION_BOOLEAN
)
188 new_vals
[i
] = options
[i
].val
;
191 while (!SCM_NULL_OR_NIL_P (args
))
193 SCM name
= SCM_CAR (args
);
196 for (i
= 0; options
[i
].name
&& !found
; ++i
)
198 if (scm_is_eq (name
, SCM_PACK (options
[i
].name
)))
200 switch (options
[i
].type
)
202 case SCM_OPTION_BOOLEAN
:
205 case SCM_OPTION_INTEGER
:
206 args
= SCM_CDR (args
);
207 new_vals
[i
] = scm_to_size_t (scm_car (args
));
210 args
= SCM_CDR (args
);
211 new_vals
[i
] = SCM_UNPACK (scm_car (args
));
219 scm_misc_error (s
, "Unknown option name: ~S", scm_list_1 (name
));
221 args
= SCM_CDR (args
);
227 for (i
= 0; options
[i
].name
; ++i
)
228 options
[i
].val
= new_vals
[i
];
233 scm_options (SCM args
, scm_t_option options
[], const char *s
)
235 return scm_options_try (args
, options
, s
, 0);
239 scm_options_try (SCM args
, scm_t_option options
[], const char *s
,
242 if (SCM_UNBNDP (args
))
243 return get_option_setting (options
);
244 else if (!SCM_NULL_OR_NIL_P (args
) && !scm_is_pair (args
))
245 /* Dirk:FIXME:: This criterion should be improved. IMO it is better to
246 * demand that args is #t if documentation should be shown than to say
247 * that every argument except a list will print out documentation. */
248 return get_documented_option_setting (options
);
252 SCM_ASSERT (scm_is_true (scm_list_p (args
)), args
, 1, s
);
253 old_setting
= get_option_setting (options
);
254 change_option_setting (args
, options
, s
, dry_run
);
261 scm_init_opts (SCM (*func
) (SCM
), scm_t_option options
[])
265 for (i
= 0; options
[i
].name
; ++i
)
267 SCM name
= scm_from_utf8_symbol (options
[i
].name
);
268 options
[i
].name
= (char *) SCM_UNPACK (name
);
270 func (SCM_UNDEFINED
);
277 #include "libguile/options.x"