| 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 |
| 15 | * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, |
| 16 | * Boston, MA 02111-1307 USA |
| 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. |
| 40 | * If you do not wish that, delete this exception notice. */ |
| 41 | \f |
| 42 | |
| 43 | #include <stdio.h> |
| 44 | #include "_scm.h" |
| 45 | #include "eval.h" |
| 46 | #include "alist.h" |
| 47 | #include "fluids.h" |
| 48 | |
| 49 | #include "dynwind.h" |
| 50 | \f |
| 51 | |
| 52 | /* {Dynamic wind} |
| 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 | */ |
| 64 | |
| 65 | |
| 66 | |
| 67 | SCM_PROC(s_dynamic_wind, "dynamic-wind", 3, 0, 0, scm_dynamic_wind); |
| 68 | |
| 69 | SCM |
| 70 | scm_dynamic_wind (thunk1, thunk2, thunk3) |
| 71 | SCM thunk1; |
| 72 | SCM thunk2; |
| 73 | SCM thunk3; |
| 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 | |
| 84 | |
| 85 | #ifdef GUILE_DEBUG |
| 86 | SCM_PROC (s_wind_chain, "wind-chain", 0, 0, 0, scm_wind_chain); |
| 87 | |
| 88 | SCM |
| 89 | scm_wind_chain () |
| 90 | { |
| 91 | return scm_dynwinds; |
| 92 | } |
| 93 | #endif |
| 94 | |
| 95 | |
| 96 | void |
| 97 | scm_dowinds (to, delta) |
| 98 | SCM to; |
| 99 | long delta; |
| 100 | { |
| 101 | tail: |
| 102 | if (scm_dynwinds == to); |
| 103 | else if (0 > delta) |
| 104 | { |
| 105 | SCM wind_elt; |
| 106 | SCM wind_key; |
| 107 | |
| 108 | scm_dowinds (SCM_CDR (to), 1 + delta); |
| 109 | wind_elt = SCM_CAR (to); |
| 110 | #if 0 |
| 111 | if (SCM_INUMP (wind_elt)) |
| 112 | { |
| 113 | scm_cross_dynwind_binding_scope (wind_elt, 0); |
| 114 | } |
| 115 | else |
| 116 | #endif |
| 117 | { |
| 118 | wind_key = SCM_CAR (wind_elt); |
| 119 | if (!(SCM_NIMP (wind_key) && SCM_SYMBOLP (wind_key)) |
| 120 | && (wind_key != SCM_BOOL_F) |
| 121 | && (wind_key != SCM_BOOL_T)) |
| 122 | { |
| 123 | if (SCM_NIMP (wind_key) && SCM_CONSP (wind_key)) |
| 124 | scm_swap_fluids (wind_key, SCM_CDR (wind_elt)); |
| 125 | else |
| 126 | scm_apply (wind_key, SCM_EOL, SCM_EOL); |
| 127 | } |
| 128 | } |
| 129 | scm_dynwinds = to; |
| 130 | } |
| 131 | else |
| 132 | { |
| 133 | SCM from; |
| 134 | SCM wind_elt; |
| 135 | SCM wind_key; |
| 136 | |
| 137 | from = SCM_CDR (SCM_CAR (scm_dynwinds)); |
| 138 | wind_elt = SCM_CAR (scm_dynwinds); |
| 139 | scm_dynwinds = SCM_CDR (scm_dynwinds); |
| 140 | #if 0 |
| 141 | if (SCM_INUMP (wind_elt)) |
| 142 | { |
| 143 | scm_cross_dynwind_binding_scope (wind_elt, 0); |
| 144 | } |
| 145 | else |
| 146 | #endif |
| 147 | { |
| 148 | wind_key = SCM_CAR (wind_elt); |
| 149 | if (!(SCM_NIMP (wind_key) && SCM_SYMBOLP (wind_key)) |
| 150 | && (wind_key != SCM_BOOL_F) |
| 151 | && (wind_key != SCM_BOOL_T)) |
| 152 | { |
| 153 | if (SCM_NIMP (wind_key) && SCM_CONSP (wind_key)) |
| 154 | scm_swap_fluids_reverse (wind_key, from); |
| 155 | else |
| 156 | scm_apply (from, SCM_EOL, SCM_EOL); |
| 157 | } |
| 158 | } |
| 159 | delta--; |
| 160 | goto tail; /* scm_dowinds(to, delta-1); */ |
| 161 | } |
| 162 | } |
| 163 | |
| 164 | |
| 165 | |
| 166 | void |
| 167 | scm_init_dynwind () |
| 168 | { |
| 169 | #include "dynwind.x" |
| 170 | } |