libguile/readline.c

   1 /* readline.c --- line editing support for Guile */
   2
   3 /*      Copyright (C) 1997 Free Software Foundation, Inc.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2, or (at your option)
   8  * any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this software; see the file COPYING.  If not, write to
  17  * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  18  *
  19  * As a special exception, the Free Software Foundation gives permission
  20  * for additional uses of the text contained in its release of GUILE.
  21  *
  22  * The exception is that, if you link the GUILE library with other files
  23  * to produce an executable, this does not by itself cause the
  24  * resulting executable to be covered by the GNU General Public License.
  25  * Your use of that executable is in no way restricted on account of
  26  * linking the GUILE library code into it.
  27  *
  28  * This exception does not however invalidate any other reasons why
  29  * the executable file might be covered by the GNU General Public License.
  30  *
  31  * This exception applies only to the code released by the
  32  * Free Software Foundation under the name GUILE.  If you copy
  33  * code from other Free Software Foundation releases into a copy of
  34  * GUILE, as the General Public License permits, the exception does
  35  * not apply to the code that you add in this way.  To avoid misleading
  36  * anyone as to the status of such modified files, you must delete
  37  * this exception notice from them.
  38  *
  39  * If you write modifications of your own for GUILE, it is your choice
  40  * whether to permit this exception to apply to your modifications.
  41  * If you do not wish that, delete this exception notice.
  42  */
  43 \f
  44
  45 #include "_scm.h"
  46 #ifdef HAVE_LIBREADLINE
  47 #include <libguile.h>
  48 #include <readline.h>
  49 #include <gh.h>
  50 #include <readline/readline.h>
  51 #include <readline/history.h>
  52
  53 static int
  54 current_input_getc ()
  55 {
  56   return scm_getc (scm_cur_inp);
  57 }
  58
  59 SCM_PROC (s_readline, "readline", 0, 1, 0, scm_readline);
  60
  61 SCM
  62 scm_readline (SCM text)
  63 {
  64   SCM ret;
  65   char* s;
  66   char* prompt;
  67
  68   if (! SCM_UNBNDP (text))
  69     {
  70       SCM_ASSERT ((SCM_NIMP(text) && SCM_STRINGP(text)), text, SCM_ARG1,
  71                   s_readline);
  72       SCM_COERCE_SUBSTR (text);
  73     }
  74
  75   prompt = SCM_UNBNDP (text) ? "" : SCM_CHARS (text);
  76
  77   s = readline (prompt);
  78   if (s)
  79     ret = scm_makfrom0str (s);
  80   else
  81     ret = SCM_EOF_VAL;
  82
  83   free (s);
  84
  85   return ret;
  86 }
  87
  88 SCM_PROC (s_add_history, "add-history", 1, 0, 0, scm_add_history);
  89
  90 SCM
  91 scm_add_history (SCM text)
  92 {
  93   char* s;
  94   SCM_ASSERT ((SCM_NIMP(text) && SCM_STRINGP(text)), text, SCM_ARG1,
  95               s_add_history);
  96   SCM_COERCE_SUBSTR (text);
  97
  98   SCM_DEFER_INTS;
  99   s = SCM_CHARS (text);
 100   add_history (strdup (s));
 101   SCM_ALLOW_INTS;
 102
 103   return SCM_UNSPECIFIED;
 104 }
 105
 106 static SCM subr_filename_completion_function;
 107 static char s_filename_completion_function[] = "filename-completion-function";
 108
 109 SCM
 110 scm_filename_completion_function (SCM text, SCM continuep)
 111 {
 112   char *s;
 113   SCM ans;
 114   SCM_ASSERT (SCM_NIMP (text) && SCM_STRINGP (text),
 115               text,
 116               SCM_ARG1,
 117               s_filename_completion_function);
 118   SCM_COERCE_SUBSTR (text);
 119   s = filename_completion_function (SCM_CHARS (text), SCM_NFALSEP (continuep));
 120   ans = scm_makfrom0str (s);
 121   free (s);
 122   return ans;
 123 }
 124
 125 /*
 126  * The following has been modified from code contributed by
 127  * Andrew Archibald <aarchiba@undergrad.math.uwaterloo.ca>
 128  */
 129
 130 SCM scm_readline_completion_function_var;
 131
 132 static SCM
 133 apply (SCM a)
 134 {
 135   return scm_apply (SCM_CAR (a), SCM_CDR (a), SCM_EOL);
 136 }
 137
 138 static char *
 139 completion_function (char *text, int continuep)
 140 {
 141   SCM_STACKITEM mark;
 142   SCM compfunc = SCM_CDR (scm_readline_completion_function_var);
 143   SCM res;
 144
 145   if (SCM_FALSEP (compfunc))
 146     return NULL; /* #f => completion disabled */
 147   else
 148     {
 149       SCM t = scm_makfrom0str (text);
 150       SCM c = continuep ? SCM_BOOL_T : SCM_BOOL_F;
 151       res = scm_internal_cwdr ((scm_catch_body_t) apply,
 152                                (void *) SCM_LIST3 (compfunc, t, c),
 153                                scm_handle_by_throw,
 154                                0,
 155                                &mark);
 156
 157       if (SCM_FALSEP (res))
 158         return NULL;
 159
 160       if (!(SCM_NIMP (res) && SCM_STRINGP (res)))
 161         scm_misc_error (s_readline,
 162                         "Completion function returned bogus value: %S",
 163                         SCM_LIST1 (res));
 164       SCM_COERCE_SUBSTR (res);
 165       return strdup (SCM_CHARS (res));
 166     }
 167 }
 168
 169
 170 void
 171 scm_init_readline ()
 172 {
 173 #include "readline.x"
 174   subr_filename_completion_function
 175     = scm_make_subr (s_filename_completion_function,
 176                      scm_tc7_subr_2,
 177                      scm_filename_completion_function);
 178   scm_readline_completion_function_var
 179     = scm_sysintern ("*readline-completion-function*", SCM_BOOL_F);
 180   rl_getc_function = current_input_getc;
 181   rl_completion_entry_function = (Function*) completion_function;
 182   scm_add_feature ("readline");
 183 }
 184
 185 #endif