libguile/vports.c

   1 /*      Copyright (C) 1995,1996,1998,1999 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 "chars.h"
  47 #include "fports.h"
  48
  49 #include "vports.h"
  50
  51 #ifdef HAVE_STRING_H
  52 #include <string.h>
  53 #endif
  54
  55 \f
  56
  57 /* {Ports - soft ports}
  58  *
  59  */
  60
  61
  62
  63 static int prinsfpt SCM_P ((SCM exp, SCM port, scm_print_state *pstate));
  64
  65 static int
  66 prinsfpt (exp, port, pstate)
  67      SCM exp;
  68      SCM port;
  69      scm_print_state *pstate;
  70 {
  71   scm_prinport (exp, port, "soft");
  72   return !0;
  73 }
  74
  75 static void
  76 sfflush (SCM port)
  77 {
  78   scm_port *pt = SCM_PTAB_ENTRY (port);
  79   SCM stream = pt->stream;
  80
  81   if (pt->write_pos > pt->write_buf)
  82     {
  83       /* write the byte. */
  84       scm_apply (SCM_VELTS (stream)[0], SCM_MAKICHR (*pt->write_buf),
  85                  scm_listofnull);
  86       pt->write_pos = pt->write_buf;
  87
  88       /* flush the output.  */
  89       {
  90         SCM f = SCM_VELTS (stream)[2];
  91
  92         if (f != SCM_BOOL_F)
  93           scm_apply (f, SCM_EOL, SCM_EOL);
  94       }
  95     }
  96 }
  97
  98 static void
  99 sf_read_flush (SCM port, int offset)
 100 {
 101 }
 102
 103 /* string output proc (element 1) is no longer called.  */
 104
 105 /* calling the flush proc (element 2) is in case old code needs it,
 106    but perhaps softports could the use port buffer in the same way as
 107    fports.  */
 108
 109 /* returns a single character.  */
 110 static int
 111 sf_fill_buffer (SCM port)
 112 {
 113   SCM p = SCM_STREAM (port);
 114   SCM ans;
 115
 116   ans = scm_apply (SCM_VELTS (p)[3], SCM_EOL, SCM_EOL); /* get char.  */
 117   if (SCM_FALSEP (ans) || SCM_EOF_OBJECT_P (ans))
 118     return EOF;
 119   SCM_ASSERT (SCM_ICHRP (ans), ans, SCM_ARG1, "sf_fill_buffer");
 120   {
 121     scm_port *pt = SCM_PTAB_ENTRY (port);
 122
 123     *pt->read_buf = SCM_ICHR (ans);
 124     pt->read_pos = pt->read_buf;
 125     pt->read_end = pt->read_buf + 1;
 126     return *pt->read_buf;
 127   }
 128 }
 129
 130
 131 static int
 132 sfclose (SCM port)
 133 {
 134   SCM p = SCM_STREAM (port);
 135   SCM f = SCM_VELTS (p)[4];
 136   if (SCM_BOOL_F == f)
 137     return 0;
 138   f = scm_apply (f, SCM_EOL, SCM_EOL);
 139   errno = 0;
 140   return SCM_BOOL_F == f ? EOF : 0;
 141 }
 142
 143
 144
 145 SCM_PROC(s_make_soft_port, "make-soft-port", 2, 0, 0, scm_make_soft_port);
 146
 147 SCM
 148 scm_make_soft_port (pv, modes)
 149      SCM pv;
 150      SCM modes;
 151 {
 152   scm_port *pt;
 153   SCM z;
 154   SCM_ASSERT (SCM_NIMP (pv) && SCM_VECTORP (pv) && 5 == SCM_LENGTH (pv), pv, SCM_ARG1, s_make_soft_port);
 155   SCM_ASSERT (SCM_NIMP (modes) && SCM_ROSTRINGP (modes), modes, SCM_ARG2, s_make_soft_port);
 156   SCM_COERCE_SUBSTR (modes);
 157   SCM_NEWCELL (z);
 158   SCM_DEFER_INTS;
 159   pt = scm_add_to_port_table (z);
 160   SCM_SETCAR (z, scm_tc16_sfport | scm_mode_bits (SCM_ROCHARS (modes)));
 161   SCM_SETPTAB_ENTRY (z, pt);
 162   SCM_SETSTREAM (z, pv);
 163   pt->read_pos = pt->read_buf = pt->read_end = &pt->shortbuf;
 164   pt->write_buf = pt->write_pos = &pt->shortbuf;
 165   pt->read_buf_size = pt->write_buf_size = 1;
 166   pt->write_end = pt->write_buf + pt->write_buf_size;
 167   pt->rw_random = 0;
 168   SCM_ALLOW_INTS;
 169   return z;
 170 }
 171
 172
 173 static int
 174 noop0 (SCM port)
 175 {
 176   return 0;
 177 }
 178
 179
 180 scm_ptobfuns scm_sfptob =
 181 {
 182   scm_markstream,
 183   noop0,
 184   prinsfpt,
 185   0,
 186   sfflush,
 187   sf_read_flush,
 188   sfclose,
 189   sf_fill_buffer,
 190   0,
 191   0,
 192   0,
 193 };
 194
 195
 196
 197 void
 198 scm_init_vports ()
 199 {
 200 #include "vports.x"
 201 }
 202