/* Copyright (C) 1995,1996,1998,1999,2000,2001, 2002, 2003, 2006, 2009, 2010 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 3 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 */ #ifdef HAVE_CONFIG_H # include #endif #include #include #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 #endif /* {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); 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)); /* DATA is assumed to be a locale-encoded C string, which makes it hard to reliably pass binary data to a soft port. It can be achieved by choosing a Latin-1 locale, though, but the recommended approach is to use an R6RS "custom binary output port" instead. */ 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; scm_t_port *pt; 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"); pt = SCM_PTAB_ENTRY (port); if (pt->encoding == NULL) { 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; } else scm_ungetc (SCM_CHAR (ans), port); return SCM_CHAR (ans); } 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{} #\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_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: */