Commit | Line | Data |
---|---|---|
0f2d19dd JB |
1 | /* Copyright (C) 1995,1996 Free Software Foundation, Inc. |
2 | * | |
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) | |
6 | * any later version. | |
7 | * | |
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. | |
12 | * | |
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 | |
82892bed JB |
15 | * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, |
16 | * Boston, MA 02111-1307 USA | |
0f2d19dd JB |
17 | * |
18 | * As a special exception, the Free Software Foundation gives permission | |
19 | * for additional uses of the text contained in its release of GUILE. | |
20 | * | |
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. | |
26 | * | |
27 | * This exception does not however invalidate any other reasons why | |
28 | * the executable file might be covered by the GNU General Public License. | |
29 | * | |
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. | |
37 | * | |
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. | |
82892bed | 40 | * If you do not wish that, delete this exception notice. */ |
0f2d19dd JB |
41 | \f |
42 | ||
43 | #include <stdio.h> | |
44 | #include "_scm.h" | |
20e6290e JB |
45 | #include "eval.h" |
46 | #include "alist.h" | |
b3460a50 | 47 | #include "fluids.h" |
0f2d19dd | 48 | |
20e6290e | 49 | #include "dynwind.h" |
0f2d19dd JB |
50 | \f |
51 | ||
52 | /* {Dynamic wind} | |
b3460a50 MV |
53 | |
54 | Things that can be on the wind list: | |
55 | ||
56 | (enter-proc . leave-proc) dynamic-wind | |
57 | (tag . jmpbuf) catch | |
58 | (tag . lazy-catch) lazy-catch | |
59 | tag is either a symbol or a boolean | |
60 | ||
61 | ((fluid ...) . (value ...)) with-fluids | |
62 | ||
63 | */ | |
0f2d19dd JB |
64 | |
65 | ||
66 | ||
67 | SCM_PROC(s_dynamic_wind, "dynamic-wind", 3, 0, 0, scm_dynamic_wind); | |
1cc91f1b | 68 | |
0f2d19dd JB |
69 | SCM |
70 | scm_dynamic_wind (thunk1, thunk2, thunk3) | |
71 | SCM thunk1; | |
72 | SCM thunk2; | |
73 | SCM thunk3; | |
0f2d19dd JB |
74 | { |
75 | SCM ans; | |
76 | scm_apply (thunk1, SCM_EOL, SCM_EOL); | |
77 | scm_dynwinds = scm_acons (thunk1, thunk3, scm_dynwinds); | |
78 | ans = scm_apply (thunk2, SCM_EOL, SCM_EOL); | |
79 | scm_dynwinds = SCM_CDR (scm_dynwinds); | |
80 | scm_apply (thunk3, SCM_EOL, SCM_EOL); | |
81 | return ans; | |
82 | } | |
83 | ||
1cc91f1b | 84 | |
0f2d19dd JB |
85 | void |
86 | scm_dowinds (to, delta) | |
87 | SCM to; | |
88 | long delta; | |
0f2d19dd JB |
89 | { |
90 | tail: | |
91 | if (scm_dynwinds == to); | |
92 | else if (0 > delta) | |
93 | { | |
94 | SCM wind_elt; | |
95 | SCM wind_key; | |
96 | ||
97 | scm_dowinds (SCM_CDR (to), 1 + delta); | |
98 | wind_elt = SCM_CAR (to); | |
99 | #if 0 | |
100 | if (SCM_INUMP (wind_elt)) | |
101 | { | |
102 | scm_cross_dynwind_binding_scope (wind_elt, 0); | |
103 | } | |
104 | else | |
105 | #endif | |
106 | { | |
107 | wind_key = SCM_CAR (wind_elt); | |
b3460a50 | 108 | if (!(SCM_NIMP (wind_key) && SCM_SYMBOLP (wind_key)) |
0f2d19dd JB |
109 | && (wind_key != SCM_BOOL_F) |
110 | && (wind_key != SCM_BOOL_T)) | |
b3460a50 MV |
111 | { |
112 | if (SCM_NIMP (wind_key) && SCM_CONSP (wind_key)) | |
113 | scm_swap_fluids (wind_key, SCM_CDR (wind_elt)); | |
114 | else | |
115 | scm_apply (wind_key, SCM_EOL, SCM_EOL); | |
116 | } | |
0f2d19dd JB |
117 | } |
118 | scm_dynwinds = to; | |
119 | } | |
120 | else | |
121 | { | |
122 | SCM from; | |
123 | SCM wind_elt; | |
124 | SCM wind_key; | |
125 | ||
126 | from = SCM_CDR (SCM_CAR (scm_dynwinds)); | |
127 | wind_elt = SCM_CAR (scm_dynwinds); | |
128 | scm_dynwinds = SCM_CDR (scm_dynwinds); | |
129 | #if 0 | |
130 | if (SCM_INUMP (wind_elt)) | |
131 | { | |
132 | scm_cross_dynwind_binding_scope (wind_elt, 0); | |
133 | } | |
134 | else | |
135 | #endif | |
136 | { | |
137 | wind_key = SCM_CAR (wind_elt); | |
b3460a50 | 138 | if (!(SCM_NIMP (wind_key) && SCM_SYMBOLP (wind_key)) |
0f2d19dd JB |
139 | && (wind_key != SCM_BOOL_F) |
140 | && (wind_key != SCM_BOOL_T)) | |
b3460a50 MV |
141 | { |
142 | if (SCM_NIMP (wind_key) && SCM_CONSP (wind_key)) | |
143 | scm_swap_fluids_reverse (wind_key, from); | |
144 | else | |
145 | scm_apply (from, SCM_EOL, SCM_EOL); | |
146 | } | |
0f2d19dd JB |
147 | } |
148 | delta--; | |
149 | goto tail; /* scm_dowinds(to, delta-1); */ | |
150 | } | |
151 | } | |
152 | ||
153 | ||
1cc91f1b | 154 | |
0f2d19dd JB |
155 | void |
156 | scm_init_dynwind () | |
0f2d19dd JB |
157 | { |
158 | #include "dynwind.x" | |
159 | } |