1 /* Copyright (C) 1995, 1996, 1998 Free Software Foundation
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2, or (at your option)
8 * This program 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
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this software; see the file COPYING. If not, write to
15 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
16 * Boston, MA 02111-1307 USA
18 * As a special exception, the Free Software Foundation gives permission
19 * for additional uses of the text contained in its release of GUILE.
21 * The exception is that, if you link the GUILE library with other files
22 * to produce an executable, this does not by itself cause the
23 * resulting executable to be covered by the GNU General Public License.
24 * Your use of that executable is in no way restricted on account of
25 * linking the GUILE library code into it.
27 * This exception does not however invalidate any other reasons why
28 * the executable file might be covered by the GNU General Public License.
30 * This exception applies only to the code released by the
31 * Free Software Foundation under the name GUILE. If you copy
32 * code from other Free Software Foundation releases into a copy of
33 * GUILE, as the General Public License permits, the exception does
34 * not apply to the code that you add in this way. To avoid misleading
35 * anyone as to the status of such modified files, you must delete
36 * this exception notice from them.
38 * If you write modifications of your own for GUILE, it is your choice
39 * whether to permit this exception to apply to your modifications.
40 * If you do not wish that, delete this exception notice.
42 * The author can be reached at djurfeldt@nada.kth.se
43 * Mikael Djurfeldt, SANS/NADA KTH, 10044 STOCKHOLM, SWEDEN */
45 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
46 gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
58 * This is the basic interface for low-level configuration of the
59 * Guile library. It is used for configuring the reader, evaluator,
60 * printer and debugger.
64 * 1. Altering option settings can have side effects.
65 * 2. Option values can be stored in native format.
66 * (Important for efficiency in, e. g., the evaluator.)
67 * 3. Doesn't use up name space.
68 * 4. Options can be naturally grouped => ease of use.
71 /* scm_options is the core of all options interface procedures.
75 * Run time options in Guile are arranged in groups. Each group
76 * affects a certain aspect of the behaviour of the library.
78 * An "options interface procedure" manages one group of options. It
79 * can be used to check or set options, or to get documentation for
80 * all options of a group. The options interface procedure is not
81 * intended to be called directly by the user. The user should
85 * (<group>-options 'help)
86 * (<group>-options 'full)
88 * to display current option settings (The second version also
89 * displays documentation. The third version also displays
90 * information about programmer's options.), and
92 * (<group>-enable '<option-symbol>)
93 * (<group>-disable '<option-symbol>)
94 * (<group>-set! <option-symbol> <value>)
95 * (<group>-options <option setting>)
97 * to alter the state of an option (The last version sets all
98 * options according to <option setting>.) where <group> is the name
99 * of the option group.
101 * An "option setting" represents the state of all low-level options
102 * managed by one options interface procedure. It is a list of
103 * single symbols and symbols followed by a value.
105 * For boolean options, the presence of the symbol of that option in
106 * the option setting indicates a true value. If the symbol isn't a
107 * member of the option setting this represents a false value.
109 * Other options are represented by a symbol followed by the value.
111 * If scm_options is called without arguments, the current option
112 * setting is returned. If the argument is an option setting, options
113 * are altered and the old setting is returned. If the argument isn't
114 * a list, a list of sublists is returned, where each sublist contains
115 * option name, value and documentation string.
118 SCM_SYMBOL (scm_yes_sym
, "yes");
119 SCM_SYMBOL (scm_no_sym
, "no");
121 static SCM protected_objects
;
124 scm_options (SCM arg
, scm_option options
[], int n
, const char *s
)
126 int i
, docp
= (!SCM_UNBNDP (arg
)
128 && (SCM_IMP (arg
) || SCM_NCONSP (arg
)));
129 /* Let `arg' GC protect the arguments */
130 SCM new_mode
= arg
, ans
= SCM_EOL
, ls
;
131 for (i
= 0; i
< n
; ++i
)
133 ls
= docp
? scm_cons ((SCM
) options
[i
].doc
, SCM_EOL
) : ans
;
134 switch (options
[i
].type
)
136 case SCM_OPTION_BOOLEAN
:
138 ls
= scm_cons ((int) options
[i
].val
143 case SCM_OPTION_INTEGER
:
144 ls
= scm_cons (SCM_MAKINUM ((int) options
[i
].val
), ls
);
147 ls
= scm_cons ((SCM
) options
[i
].val
, ls
);
149 if (!((options
[i
].type
== SCM_OPTION_BOOLEAN
)
151 && ! (int) options
[i
].val
))
152 ls
= scm_cons ((SCM
) options
[i
].name
, ls
);
153 ans
= docp
? scm_cons (ls
, ans
) : ls
;
155 if (!(SCM_UNBNDP (new_mode
) || docp
))
157 unsigned long *flags
;
158 flags
= (unsigned long *) scm_must_malloc (n
* sizeof (unsigned long),
160 for (i
= 0; i
< n
; ++i
)
161 if (options
[i
].type
== SCM_OPTION_BOOLEAN
)
164 flags
[i
] = (unsigned long) options
[i
].val
;
165 while (SCM_NNULLP (new_mode
))
167 SCM_ASSERT (SCM_CONSP (new_mode
),
171 for (i
= 0; i
< n
; ++i
)
172 if (SCM_CAR (new_mode
) == (SCM
) options
[i
].name
)
173 switch (options
[i
].type
)
175 case SCM_OPTION_BOOLEAN
:
178 case SCM_OPTION_INTEGER
:
179 new_mode
= SCM_CDR (new_mode
);
180 SCM_ASSERT ( SCM_CONSP (new_mode
)
181 && SCM_INUMP (SCM_CAR (new_mode
)),
185 flags
[i
] = (unsigned long) SCM_INUM (SCM_CAR (new_mode
));
188 new_mode
= SCM_CDR (new_mode
);
189 flags
[i
] = SCM_CARBITS (new_mode
);
193 scm_must_free ((char *) flags
);
194 scm_wta (SCM_CAR (new_mode
), "Unknown mode flag", s
);
197 new_mode
= SCM_CDR (new_mode
);
199 for (i
= 0; i
< n
; ++i
)
201 // scm_option doesn't know if its a long or an SCM
202 if (options
[i
].type
== SCM_OPTION_SCM
)
203 SCM_SETCDR (protected_objects
,
204 scm_cons (SCM_SCM(flags
[i
]),
205 scm_delq1_x (SCM_SCM(options
[i
].val
),
206 SCM_CDR (protected_objects
))));
207 options
[i
].val
= flags
[i
];
209 scm_must_free ((char *) flags
);
216 scm_init_opts (SCM (*func
) (SCM
), scm_option options
[], int n
)
220 for (i
= 0; i
< n
; ++i
)
222 options
[i
].name
= (char *) SCM_CAR (scm_sysintern0 (options
[i
].name
));
223 options
[i
].doc
= (char *) scm_permanent_object (scm_take0str
225 if (options
[i
].type
== SCM_OPTION_SCM
)
226 SCM_SETCDR (protected_objects
,
227 scm_cons (SCM_SCM(options
[i
].val
), SCM_CDR (protected_objects
)));
229 func (SCM_UNDEFINED
);
236 protected_objects
= scm_permanent_object (scm_cons (SCM_UNDEFINED
, SCM_EOL
));