+/* Copyright (C) 1995,1996,1998,1999,2000,2001, 2002, 2003, 2006 Free Software Foundation, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+
+\f
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdio.h>
+#include <errno.h>
+
+#include "libguile/_scm.h"
+#include "libguile/eval.h"
+#include "libguile/chars.h"
+#include "libguile/fports.h"
+#include "libguile/root.h"
+#include "libguile/strings.h"
+#include "libguile/vectors.h"
+
+#include "libguile/validate.h"
+#include "libguile/vports.h"
+
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+
+\f
+
+/* {Ports - soft ports}
+ *
+ */
+
+
+static scm_t_bits scm_tc16_sfport;
+
+
+static void
+sf_flush (SCM port)
+{
+ scm_t_port *pt = SCM_PTAB_ENTRY (port);
+ SCM stream = SCM_PACK (pt->stream);
+
+ if (pt->write_pos > pt->write_buf)
+ {
+ /* write the byte. */
+ scm_call_1 (SCM_SIMPLE_VECTOR_REF (stream, 0),
+ SCM_MAKE_CHAR (*pt->write_buf));
+ pt->write_pos = pt->write_buf;
+
+ /* flush the output. */
+ {
+ SCM f = SCM_SIMPLE_VECTOR_REF (stream, 2);
+
+ if (scm_is_true (f))
+ scm_call_0 (f);
+ }
+ }
+}
+
+static void
+sf_write (SCM port, const void *data, size_t size)
+{
+ SCM p = SCM_PACK (SCM_STREAM (port));
+
+ scm_call_1 (SCM_SIMPLE_VECTOR_REF (p, 1),
+ scm_from_locale_stringn ((char *) data, size));
+}
+
+/* calling the flush proc (element 2) is in case old code needs it,
+ but perhaps softports could the use port buffer in the same way as
+ fports. */
+
+/* places a single char in the input buffer. */
+static int
+sf_fill_input (SCM port)
+{
+ SCM p = SCM_PACK (SCM_STREAM (port));
+ SCM ans;
+
+ ans = scm_call_0 (SCM_SIMPLE_VECTOR_REF (p, 3)); /* get char. */
+ if (scm_is_false (ans) || SCM_EOF_OBJECT_P (ans))
+ return EOF;
+ SCM_ASSERT (SCM_CHARP (ans), ans, SCM_ARG1, "sf_fill_input");
+ {
+ scm_t_port *pt = SCM_PTAB_ENTRY (port);
+
+ *pt->read_buf = SCM_CHAR (ans);
+ pt->read_pos = pt->read_buf;
+ pt->read_end = pt->read_buf + 1;
+ return *pt->read_buf;
+ }
+}
+
+
+static int
+sf_close (SCM port)
+{
+ SCM p = SCM_PACK (SCM_STREAM (port));
+ SCM f = SCM_SIMPLE_VECTOR_REF (p, 4);
+ if (scm_is_false (f))
+ return 0;
+ f = scm_call_0 (f);
+ errno = 0;
+ return scm_is_false (f) ? EOF : 0;
+}
+
+
+static int
+sf_input_waiting (SCM port)
+{
+ SCM p = SCM_PACK (SCM_STREAM (port));
+ if (SCM_SIMPLE_VECTOR_LENGTH (p) >= 6)
+ {
+ SCM f = SCM_SIMPLE_VECTOR_REF (p, 5);
+ if (scm_is_true (f))
+ return scm_to_int (scm_call_0 (f));
+ }
+ /* Default is such that char-ready? for soft ports returns #t, as it
+ did before this extension was implemented. */
+ return 1;
+}
+
+
+
+SCM_DEFINE (scm_make_soft_port, "make-soft-port", 2, 0, 0,
+ (SCM pv, SCM modes),
+ "Return a port capable of receiving or delivering characters as\n"
+ "specified by the @var{modes} string (@pxref{File Ports,\n"
+ "open-file}). @var{pv} must be a vector of length 5 or 6. Its\n"
+ "components are as follows:\n"
+ "\n"
+ "@enumerate 0\n"
+ "@item\n"
+ "procedure accepting one character for output\n"
+ "@item\n"
+ "procedure accepting a string for output\n"
+ "@item\n"
+ "thunk for flushing output\n"
+ "@item\n"
+ "thunk for getting one character\n"
+ "@item\n"
+ "thunk for closing port (not by garbage collection)\n"
+ "@item\n"
+ "(if present and not @code{#f}) thunk for computing the number of\n"
+ "characters that can be read from the port without blocking.\n"
+ "@end enumerate\n"
+ "\n"
+ "For an output-only port only elements 0, 1, 2, and 4 need be\n"
+ "procedures. For an input-only port only elements 3 and 4 need\n"
+ "be procedures. Thunks 2 and 4 can instead be @code{#f} if\n"
+ "there is no useful operation for them to perform.\n"
+ "\n"
+ "If thunk 3 returns @code{#f} or an @code{eof-object}\n"
+ "(@pxref{Input, eof-object?, ,r5rs, The Revised^5 Report on\n"
+ "Scheme}) it indicates that the port has reached end-of-file.\n"
+ "For example:\n"
+ "\n"
+ "@lisp\n"
+ "(define stdout (current-output-port))\n"
+ "(define p (make-soft-port\n"
+ " (vector\n"
+ " (lambda (c) (write c stdout))\n"
+ " (lambda (s) (display s stdout))\n"
+ " (lambda () (display \".\" stdout))\n"
+ " (lambda () (char-upcase (read-char)))\n"
+ " (lambda () (display \"@@\" stdout)))\n"
+ " \"rw\"))\n"
+ "\n"
+ "(write p p) @result{} #<input-output: soft 8081e20>\n"
+ "@end lisp")
+#define FUNC_NAME s_scm_make_soft_port
+{
+ int vlen;
+ scm_t_port *pt;
+ SCM z;
+
+ SCM_VALIDATE_VECTOR (1, pv);
+ vlen = SCM_SIMPLE_VECTOR_LENGTH (pv);
+ SCM_ASSERT ((vlen == 5) || (vlen == 6), pv, 1, FUNC_NAME);
+ SCM_VALIDATE_STRING (2, modes);
+
+ scm_i_scm_pthread_mutex_lock (&scm_i_port_table_mutex);
+ z = scm_new_port_table_entry (scm_tc16_sfport);
+ pt = SCM_PTAB_ENTRY (z);
+ scm_port_non_buffer (pt);
+ SCM_SET_CELL_TYPE (z, scm_tc16_sfport | scm_i_mode_bits (modes));
+
+ SCM_SETSTREAM (z, SCM_UNPACK (pv));
+ scm_i_pthread_mutex_unlock (&scm_i_port_table_mutex);
+ return z;
+}
+#undef FUNC_NAME
+
+
+static scm_t_bits
+scm_make_sfptob ()
+{
+ scm_t_bits tc = scm_make_port_type ("soft", sf_fill_input, sf_write);
+
+ scm_set_port_mark (tc, scm_markstream);
+ scm_set_port_flush (tc, sf_flush);
+ scm_set_port_close (tc, sf_close);
+ scm_set_port_input_waiting (tc, sf_input_waiting);
+
+ return tc;
+}
+
+void
+scm_init_vports ()
+{
+ scm_tc16_sfport = scm_make_sfptob ();
+
+#include "libguile/vports.x"
+}
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/