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 static void
  63 sfflush (SCM port)
  64 {
  65   scm_port *pt = SCM_PTAB_ENTRY (port);
  66   SCM stream = pt->stream;
  67
  68   if (pt->write_pos > pt->write_buf)
  69     {
  70       /* write the byte. */
  71       scm_apply (SCM_VELTS (stream)[0], SCM_MAKICHR (*pt->write_buf),
  72                  scm_listofnull);
  73       pt->write_pos = pt->write_buf;
  74
  75       /* flush the output.  */
  76       {
  77         SCM f = SCM_VELTS (stream)[2];
  78
  79         if (f != SCM_BOOL_F)
  80           scm_apply (f, SCM_EOL, SCM_EOL);
  81       }
  82     }
  83 }
  84
  85 /* string output proc (element 1) is no longer called.  */
  86
  87 /* calling the flush proc (element 2) is in case old code needs it,
  88    but perhaps softports could the use port buffer in the same way as
  89    fports.  */
  90
  91 /* returns a single character.  */
  92 static int
  93 sf_fill_buffer (SCM port)
  94 {
  95   SCM p = SCM_STREAM (port);
  96   SCM ans;
  97
  98   ans = scm_apply (SCM_VELTS (p)[3], SCM_EOL, SCM_EOL); /* get char.  */
  99   if (SCM_FALSEP (ans) || SCM_EOF_OBJECT_P (ans))
 100     return EOF;
 101   SCM_ASSERT (SCM_ICHRP (ans), ans, SCM_ARG1, "sf_fill_buffer");
 102   {
 103     scm_port *pt = SCM_PTAB_ENTRY (port);
 104
 105     *pt->read_buf = SCM_ICHR (ans);
 106     pt->read_pos = pt->read_buf;
 107     pt->read_end = pt->read_buf + 1;
 108     return *pt->read_buf;
 109   }
 110 }
 111
 112
 113 static int
 114 sfclose (SCM port)
 115 {
 116   SCM p = SCM_STREAM (port);
 117   SCM f = SCM_VELTS (p)[4];
 118   if (SCM_BOOL_F == f)
 119     return 0;
 120   f = scm_apply (f, SCM_EOL, SCM_EOL);
 121   errno = 0;
 122   return SCM_BOOL_F == f ? EOF : 0;
 123 }
 124
 125
 126
 127 SCM_PROC(s_make_soft_port, "make-soft-port", 2, 0, 0, scm_make_soft_port);
 128
 129 SCM
 130 scm_make_soft_port (pv, modes)
 131      SCM pv;
 132      SCM modes;
 133 {
 134   scm_port *pt;
 135   SCM z;
 136   SCM_ASSERT (SCM_NIMP (pv) && SCM_VECTORP (pv) && 5 == SCM_LENGTH (pv), pv, SCM_ARG1, s_make_soft_port);
 137   SCM_ASSERT (SCM_NIMP (modes) && SCM_ROSTRINGP (modes), modes, SCM_ARG2, s_make_soft_port);
 138   SCM_COERCE_SUBSTR (modes);
 139   SCM_NEWCELL (z);
 140   SCM_DEFER_INTS;
 141   pt = scm_add_to_port_table (z);
 142   SCM_SETCAR (z, scm_tc16_sfport | scm_mode_bits (SCM_ROCHARS (modes)));
 143   SCM_SETPTAB_ENTRY (z, pt);
 144   SCM_SETSTREAM (z, pv);
 145   pt->read_pos = pt->read_buf = pt->read_end = &pt->shortbuf;
 146   pt->write_buf = pt->write_pos = &pt->shortbuf;
 147   pt->read_buf_size = pt->write_buf_size = 1;
 148   pt->write_end = pt->write_buf + pt->write_buf_size;
 149   pt->rw_random = 0;
 150   SCM_ALLOW_INTS;
 151   return z;
 152 }
 153
 154
 155 void scm_make_sfptob (void); /* Called from ports.c */
 156
 157 void
 158 scm_make_sfptob ()
 159 {
 160   long tc = scm_make_port_type ("soft", sf_fill_buffer, sfflush);
 161   scm_set_port_mark (tc, scm_markstream);
 162   scm_set_port_close (tc, sfclose);
 163 }
 164
 165 void
 166 scm_init_vports ()
 167 {
 168 #include "vports.x"
 169 }