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be79627c21
* libguile/vports.c (sf_flush): Remove conditional testing the position in the port's write_buf, as it is no longer used.
236 lines
6.3 KiB
C
236 lines
6.3 KiB
C
/* Copyright (C) 1995,1996,1998,1999,2000,2001, 2002, 2003, 2006, 2009, 2010 Free Software Foundation, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public License
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* as published by the Free Software Foundation; either version 3 of
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* the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301 USA
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*/
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <stdio.h>
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#include <errno.h>
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#include "libguile/_scm.h"
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#include "libguile/eval.h"
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#include "libguile/chars.h"
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#include "libguile/fports.h"
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#include "libguile/root.h"
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#include "libguile/strings.h"
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#include "libguile/vectors.h"
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#include "libguile/validate.h"
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#include "libguile/vports.h"
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#ifdef HAVE_STRING_H
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#include <string.h>
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#endif
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/* {Ports - soft ports}
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*
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*/
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static scm_t_bits scm_tc16_sfport;
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static void
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sf_flush (SCM port)
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{
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scm_t_port *pt = SCM_PTAB_ENTRY (port);
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SCM stream = SCM_PACK (pt->stream);
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SCM f = SCM_SIMPLE_VECTOR_REF (stream, 2);
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if (scm_is_true (f))
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scm_call_0 (f);
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}
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static void
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sf_write (SCM port, const void *data, size_t size)
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{
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SCM p = SCM_PACK (SCM_STREAM (port));
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/* DATA is assumed to be a locale-encoded C string, which makes it
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hard to reliably pass binary data to a soft port. It can be
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achieved by choosing a Latin-1 locale, though, but the recommended
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approach is to use an R6RS "custom binary output port" instead. */
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scm_call_1 (SCM_SIMPLE_VECTOR_REF (p, 1),
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scm_from_locale_stringn ((char *) data, size));
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}
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/* calling the flush proc (element 2) is in case old code needs it,
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but perhaps softports could the use port buffer in the same way as
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fports. */
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/* places a single char in the input buffer. */
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static int
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sf_fill_input (SCM port)
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{
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SCM p = SCM_PACK (SCM_STREAM (port));
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SCM ans;
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scm_t_port *pt;
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ans = scm_call_0 (SCM_SIMPLE_VECTOR_REF (p, 3)); /* get char. */
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if (scm_is_false (ans) || SCM_EOF_OBJECT_P (ans))
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return EOF;
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SCM_ASSERT (SCM_CHARP (ans), ans, SCM_ARG1, "sf_fill_input");
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pt = SCM_PTAB_ENTRY (port);
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if (pt->encoding == NULL)
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{
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scm_t_port *pt = SCM_PTAB_ENTRY (port);
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*pt->read_buf = SCM_CHAR (ans);
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pt->read_pos = pt->read_buf;
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pt->read_end = pt->read_buf + 1;
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return *pt->read_buf;
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}
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else
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scm_ungetc (SCM_CHAR (ans), port);
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return SCM_CHAR (ans);
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}
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static int
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sf_close (SCM port)
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{
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SCM p = SCM_PACK (SCM_STREAM (port));
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SCM f = SCM_SIMPLE_VECTOR_REF (p, 4);
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if (scm_is_false (f))
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return 0;
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f = scm_call_0 (f);
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errno = 0;
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return scm_is_false (f) ? EOF : 0;
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}
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static int
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sf_input_waiting (SCM port)
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{
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SCM p = SCM_PACK (SCM_STREAM (port));
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if (SCM_SIMPLE_VECTOR_LENGTH (p) >= 6)
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{
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SCM f = SCM_SIMPLE_VECTOR_REF (p, 5);
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if (scm_is_true (f))
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return scm_to_int (scm_call_0 (f));
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}
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/* Default is such that char-ready? for soft ports returns #t, as it
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did before this extension was implemented. */
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return 1;
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}
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SCM_DEFINE (scm_make_soft_port, "make-soft-port", 2, 0, 0,
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(SCM pv, SCM modes),
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"Return a port capable of receiving or delivering characters as\n"
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"specified by the @var{modes} string (@pxref{File Ports,\n"
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"open-file}). @var{pv} must be a vector of length 5 or 6. Its\n"
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"components are as follows:\n"
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"\n"
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"@enumerate 0\n"
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"@item\n"
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"procedure accepting one character for output\n"
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"@item\n"
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"procedure accepting a string for output\n"
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"@item\n"
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"thunk for flushing output\n"
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"@item\n"
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"thunk for getting one character\n"
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"@item\n"
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"thunk for closing port (not by garbage collection)\n"
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"@item\n"
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"(if present and not @code{#f}) thunk for computing the number of\n"
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"characters that can be read from the port without blocking.\n"
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"@end enumerate\n"
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"\n"
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"For an output-only port only elements 0, 1, 2, and 4 need be\n"
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"procedures. For an input-only port only elements 3 and 4 need\n"
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"be procedures. Thunks 2 and 4 can instead be @code{#f} if\n"
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"there is no useful operation for them to perform.\n"
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"\n"
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"If thunk 3 returns @code{#f} or an @code{eof-object}\n"
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"(@pxref{Input, eof-object?, ,r5rs, The Revised^5 Report on\n"
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"Scheme}) it indicates that the port has reached end-of-file.\n"
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"For example:\n"
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"\n"
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"@lisp\n"
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"(define stdout (current-output-port))\n"
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"(define p (make-soft-port\n"
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" (vector\n"
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" (lambda (c) (write c stdout))\n"
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" (lambda (s) (display s stdout))\n"
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" (lambda () (display \".\" stdout))\n"
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" (lambda () (char-upcase (read-char)))\n"
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" (lambda () (display \"@@\" stdout)))\n"
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" \"rw\"))\n"
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"\n"
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"(write p p) @result{} #<input-output: soft 8081e20>\n"
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"@end lisp")
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#define FUNC_NAME s_scm_make_soft_port
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{
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int vlen;
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scm_t_port *pt;
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SCM z;
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SCM_VALIDATE_VECTOR (1, pv);
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vlen = SCM_SIMPLE_VECTOR_LENGTH (pv);
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SCM_ASSERT ((vlen == 5) || (vlen == 6), pv, 1, FUNC_NAME);
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SCM_VALIDATE_STRING (2, modes);
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scm_i_scm_pthread_mutex_lock (&scm_i_port_table_mutex);
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z = scm_new_port_table_entry (scm_tc16_sfport);
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pt = SCM_PTAB_ENTRY (z);
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scm_port_non_buffer (pt);
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SCM_SET_CELL_TYPE (z, scm_tc16_sfport | scm_i_mode_bits (modes));
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SCM_SETSTREAM (z, SCM_UNPACK (pv));
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scm_i_pthread_mutex_unlock (&scm_i_port_table_mutex);
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return z;
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}
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#undef FUNC_NAME
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static scm_t_bits
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scm_make_sfptob ()
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{
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scm_t_bits tc = scm_make_port_type ("soft", sf_fill_input, sf_write);
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scm_set_port_flush (tc, sf_flush);
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scm_set_port_close (tc, sf_close);
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scm_set_port_input_waiting (tc, sf_input_waiting);
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return tc;
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}
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void
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scm_init_vports ()
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{
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scm_tc16_sfport = scm_make_sfptob ();
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#include "libguile/vports.x"
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}
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/*
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Local Variables:
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c-file-style: "gnu"
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End:
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*/
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