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-rw-r--r--doc/oldfmt.c219
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+/* Copyright (C) 2000 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.
+ */
+
+
+
+/* From NEWS:
+ *
+ * * New primitive: `simple-format', affects `scm-error', scm_display_error, & scm_error message strings
+ *
+ * (ice-9 boot) makes `format' an alias for `simple-format' until possibly
+ * extended by the more sophisticated version in (ice-9 format)
+ *
+ * (simple-format port message . args)
+ * Write MESSAGE to DESTINATION, defaulting to `current-output-port'.
+ * MESSAGE can contain ~A (was %s) and ~S (was %S) escapes. When printed,
+ * the escapes are replaced with corresponding members of ARGS:
+ * ~A formats using `display' and ~S formats using `write'.
+ * If DESTINATION is #t, then use the `current-output-port',
+ * if DESTINATION is #f, then return a string containing the formatted text.
+ * Does not add a trailing newline."
+ *
+ * The two C procedures: scm_display_error and scm_error, as well as the
+ * primitive `scm-error', now use scm_format to do their work. This means
+ * that the message strings of all code must be updated to use ~A where %s
+ * was used before, and ~S where %S was used before.
+ *
+ * During the period when there still are a lot of old Guiles out there,
+ * you might want to support both old and new versions of Guile.
+ *
+ * There are basically two methods to achieve this. Both methods use
+ * autoconf. Put
+ *
+ * AC_CHECK_FUNCS(scm_simple_format)
+ *
+ * in your configure.in.
+ *
+ * Method 1: Use the string concatenation features of ANSI C's
+ * preprocessor.
+ *
+ * In C:
+ *
+ * #ifdef HAVE_SCM_SIMPLE_FORMAT
+ * #define FMT_S "~S"
+ * #else
+ * #define FMT_S "%S"
+ * #endif
+ *
+ * Then represent each of your error messages using a preprocessor macro:
+ *
+ * #define E_SPIDER_ERROR "There's a spider in your " ## FMT_S ## "!!!"
+ *
+ * In Scheme:
+ *
+ * (define fmt-s (if (defined? 'simple-format) "~S" "%S"))
+ * (define make-message string-append)
+ *
+ * (define e-spider-error
+ * (make-message "There's a spider in your " fmt-s "!!!"))
+ *
+ * Method 2: Use the oldfmt function found in doc/oldfmt.c.
+ *
+ * In C:
+ *
+ * scm_misc_error ("picnic", scm_c_oldfmt0 ("There's a spider in your ~S!!!"),
+ * ...);
+ *
+ * In Scheme:
+ *
+ * (scm-error 'misc-error "picnic" (oldfmt "There's a spider in your ~S!!!")
+ * ...)
+ *
+ */
+
+/*
+ * Take a format string FROM adhering to the new standard format (~A and ~S
+ * as placeholders) of length N and return a string which is adapted
+ * to the format used by the Guile interpreter which you are running.
+ *
+ * On successive calls with similar strings but different storage, the
+ * same string with same storage is returned. This is necessary since
+ * the existence of a garbage collector in the system may cause the same
+ * format string to be represented with different storage at different
+ * calls.
+ */
+
+char *
+scm_c_oldfmt (char *from, int n)
+{
+#ifdef HAVE_SCM_SIMPLE_FORMAT
+ return from;
+#else
+ static struct { int n; char *from; char *to; } *strings;
+ static int size = 0;
+ static int n_strings = 0;
+ char *to;
+ int i;
+
+ for (i = 0; i < n_strings; ++i)
+ if (n == strings[i].n && strncmp (from, strings[i].from, n) == 0)
+ return strings[i].to;
+
+ if (n_strings == size)
+ {
+ if (size == 0)
+ {
+ size = 10;
+ strings = scm_must_malloc (size * sizeof (*strings), s_oldfmt);
+ }
+ else
+ {
+ int oldsize = size;
+ size = 3 * oldsize / 2;
+ strings = scm_must_realloc (strings,
+ oldsize * sizeof (*strings),
+ size * sizeof (*strings),
+ s_oldfmt);
+ }
+ }
+
+ strings[n_strings].n = n;
+ strings[n_strings].from = strncpy (scm_must_malloc (n, s_oldfmt), from, n);
+ to = strings[n_strings].to = scm_must_malloc (n + 1, s_oldfmt);
+ n_strings++;
+
+ for (i = 0; i < n; ++i)
+ {
+ if (from[i] == '~' && ++i < n)
+ {
+ if (from[i] == 'A')
+ {
+ to[i - 1] = '%';
+ to[i] = 's';
+ }
+ else if (from[i] == 'S')
+ {
+ to[i - 1] = '%';
+ to[i] = 'S';
+ }
+ else
+ {
+ to[i - 1] = '~';
+ to[i] = from[i];
+ }
+ continue;
+ }
+ to[i] = from[i];
+ }
+ to[i] = '\0';
+
+ return to;
+#endif
+}
+
+char *
+scm_c_oldfmt0 (char *s)
+{
+#ifdef HAVE_SCM_SIMPLE_FORMAT
+ return s;
+#else
+ return scm_c_oldfmt (s, strlen (s));
+#endif
+}
+
+SCM_PROC (s_oldfmt, "oldfmt", 1, 0, 0, scm_oldfmt);
+
+SCM
+scm_oldfmt (SCM s)
+{
+#ifdef HAVE_SCM_SIMPLE_FORMAT
+ return s;
+#else
+ int n;
+ SCM_ASSERT (SCM_NIMP (s) && SCM_STRINGP (s), s, 1, s_oldfmt);
+ n = SCM_LENGTH (s);
+ return scm_return_first (scm_makfromstr (scm_c_oldfmt (SCM_ROCHARS (s), n),
+ n,
+ 0),
+ s);
+#endif
+}