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author | Mikael Djurfeldt <djurfeldt@nada.kth.se> | 2000-01-12 01:54:16 +0000 |
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committer | Mikael Djurfeldt <djurfeldt@nada.kth.se> | 2000-01-12 01:54:16 +0000 |
commit | eb46d7afa05ca03fdef6d8d1039de0cb47fa5832 (patch) | |
tree | dd790e08ec3cf28933974bf94b164d40c7b1f995 /doc/oldfmt.c | |
parent | 49395101f7c06f94e9cc6cda2cf21c47fcf51927 (diff) | |
download | guile-eb46d7afa05ca03fdef6d8d1039de0cb47fa5832.tar.gz |
* oldfmt.c: New file: Used by application writers to adapt to
new-style error format strings.
Diffstat (limited to 'doc/oldfmt.c')
-rw-r--r-- | doc/oldfmt.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/doc/oldfmt.c b/doc/oldfmt.c new file mode 100644 index 000000000..bfd00fe1d --- /dev/null +++ b/doc/oldfmt.c @@ -0,0 +1,219 @@ +/* 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 +} |