/* Copyright (C) 1995,1996,1998,1999 Free Software Foundation, Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this software; see the file COPYING. If not, write to * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, * Boston, MA 02111-1307 USA * * As a special exception, the Free Software Foundation gives permission * for additional uses of the text contained in its release of GUILE. * * The exception is that, if you link the GUILE library with other files * to produce an executable, this does not by itself cause the * resulting executable to be covered by the GNU General Public License. * Your use of that executable is in no way restricted on account of * linking the GUILE library code into it. * * This exception does not however invalidate any other reasons why * the executable file might be covered by the GNU General Public License. * * This exception applies only to the code released by the * Free Software Foundation under the name GUILE. If you copy * code from other Free Software Foundation releases into a copy of * GUILE, as the General Public License permits, the exception does * not apply to the code that you add in this way. To avoid misleading * anyone as to the status of such modified files, you must delete * this exception notice from them. * * If you write modifications of your own for GUILE, it is your choice * whether to permit this exception to apply to your modifications. * If you do not wish that, delete this exception notice. */ /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999, gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */ #include #include "_scm.h" #include "eval.h" #include "chars.h" #include "fports.h" #include "scm_validate.h" #include "vports.h" #ifdef HAVE_STRING_H #include #endif /* {Ports - soft ports} * */ static void sf_flush (SCM port) { scm_port *pt = SCM_PTAB_ENTRY (port); SCM stream = pt->stream; if (pt->write_pos > pt->write_buf) { /* write the byte. */ scm_apply (SCM_VELTS (stream)[0], SCM_MAKICHR (*pt->write_buf), scm_listofnull); pt->write_pos = pt->write_buf; /* flush the output. */ { SCM f = SCM_VELTS (stream)[2]; if (f != SCM_BOOL_F) scm_apply (f, SCM_EOL, SCM_EOL); } } } static void sf_write (SCM port, const void *data, size_t size) { SCM p = SCM_STREAM (port); scm_apply (SCM_VELTS (p)[1], scm_cons (scm_makfromstr ((char *) data, size, 0), SCM_EOL), SCM_EOL); } /* 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_STREAM (port); SCM ans; ans = scm_apply (SCM_VELTS (p)[3], SCM_EOL, SCM_EOL); /* get char. */ if (SCM_FALSEP (ans) || SCM_EOF_OBJECT_P (ans)) return EOF; SCM_ASSERT (SCM_ICHRP (ans), ans, SCM_ARG1, "sf_fill_input"); { scm_port *pt = SCM_PTAB_ENTRY (port); *pt->read_buf = SCM_ICHR (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_STREAM (port); SCM f = SCM_VELTS (p)[4]; if (SCM_BOOL_F == f) return 0; f = scm_apply (f, SCM_EOL, SCM_EOL); errno = 0; return SCM_BOOL_F == f ? EOF : 0; } SCM_DEFINE (scm_make_soft_port, "make-soft-port", 2, 0, 0, (SCM pv, SCM modes), "Returns a port capable of receiving or delivering characters as\n" "specified by the @var{modes} string (@pxref{File Ports,\n" "open-file}). @var{vector} must be a vector of length 6. Its components\n" "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" "@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 be\n" "procedures. Thunks 2 and 4 can instead be @code{#f} if there is no useful\n" "operation for them to perform.\n\n" "If thunk 3 returns @code{#f} or an @code{eof-object} (@pxref{Input,\n" "eof-object?, ,r4rs, The Revised^4 Report on Scheme}) it indicates that\n" "the port has reached end-of-file. For example:\n\n" "@example\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{} #\n" "@end example") #define FUNC_NAME s_scm_make_soft_port { scm_port *pt; SCM z; SCM_VALIDATE_VECTOR_LEN (1,pv,5); SCM_VALIDATE_ROSTRING (2,modes); SCM_COERCE_SUBSTR (modes); SCM_NEWCELL (z); SCM_DEFER_INTS; pt = scm_add_to_port_table (z); SCM_SETCAR (z, scm_tc16_sfport | scm_mode_bits (SCM_ROCHARS (modes))); SCM_SETPTAB_ENTRY (z, pt); SCM_SETSTREAM (z, pv); pt->read_pos = pt->read_buf = pt->read_end = &pt->shortbuf; pt->write_buf = pt->write_pos = &pt->shortbuf; pt->read_buf_size = pt->write_buf_size = 1; pt->write_end = pt->write_buf + pt->write_buf_size; pt->rw_random = 0; SCM_ALLOW_INTS; return z; } #undef FUNC_NAME void scm_make_sfptob (void); /* Called from ports.c */ void scm_make_sfptob () { long 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); } void scm_init_vports () { #include "vports.x" }