Implement print-circle, allowing recursive and circular structures to be read. src/ChangeLog addition: 2011-09-04 Aidan Kehoe <kehoea@parhasard.net> * alloc.c: * alloc.c (ALLOC_FROB_BLOCK_LISP_OBJECT_1): * alloc.c (ALLOC_FROB_BLOCK_LISP_OBJECT): * alloc.c (cons_print_preprocess): * alloc.c (vector_print_preprocess): * alloc.c (vector_nsubst_structures_descend): * alloc.c (Fmake_symbol): * alloc.c (UNMARK_symbol): * alloc.c (sweep_symbols): * alloc.c (reinit_alloc_objects_early): * alloc.c (reinit_alloc_early): * bytecode.c: * bytecode.c (compiled_function_print_preprocess): * bytecode.c (compiled_function_nsubst_structures_descend): * bytecode.c (set_compiled_function_arglist): * bytecode.c (set_compiled_function_interactive): * bytecode.c (bytecode_objects_create): * chartab.c: * chartab.c (print_preprocess_mapper): * chartab.c (nsubst_structures_mapper): * chartab.c (char_table_nsubst_structures_descend): * chartab.c (chartab_objects_create): * elhash.c: * elhash.c (nsubst_structures_map_hash_table): * elhash.c (hash_table_nsubst_structures_descend): * elhash.c (print_preprocess_mapper): * elhash.c (hash_table_print_preprocess): * elhash.c (inchash_eq): * elhash.c (hash_table_objects_create): * elhash.c (syms_of_elhash): * elhash.h: * emacs.c (main_1): * fns.c: * fns.c (check_eq_nokey): * fns.c (Fnsubst): * fns.c (syms_of_fns): * lisp.h: * lisp.h (struct Lisp_Symbol): * lisp.h (IN_OBARRAY): * lisp.h (struct): * lisp.h (PRINT_PREPROCESS): * lread.c (read1): * lrecord.h: * lrecord.h (struct lrecord_implementation): * lrecord.h (DEFINE_DUMPABLE_MODULE_LISP_OBJECT): * print.c: * print.c (PRINT_CIRCLE_LIMIT): * print.c (print_continuous_numbering_changed): * print.c (print_prepare): * print.c (print_finish): * print.c (Fprin1_to_string): * print.c (print_cons): * print.c (print_preprocess_inchash_eq): * print.c (print_preprocess): * print.c (print_sort_get_numbers): * print.c (print_sort_compare_ordinals): * print.c (print_gensym_or_circle): * print.c (nsubst_structures_descend): * print.c (nsubst_structures): * print.c (print_internal): * print.c (print_symbol): * print.c (vars_of_print): * rangetab.c: * rangetab.c (range_table_print_preprocess): * rangetab.c (range_table_nsubst_structures_descend): * rangetab.c (rangetab_objects_create): * rangetab.c (syms_of_rangetab): * symbols.c: * symbols.c (symbol_print_preprocess): * symbols.c (Fintern): * symbols.c (Funintern): * symbols.c (reinit_symbol_objects_early): * symbols.c (init_symbols_once_early): * symsinit.h: Implement print-circle, printing circular structures in a readable fashion, and treating them appropriately on read. This is by means of two new object methods, print_preprocess (detecting circularities), and nsubst_structures_descend (replacing placeholders with the read objects). Expose the substitution to Lisp via #'nsubst and its new :descend-structures keyword. Store information as to whether symbols are interned in obarray or not in their header, making checking for keywords and uninterned symbols (and thus printing) cheaper. Default print_gensym to t, as Common Lisp does, and as a more-than-decade old comment suggests. lisp/ChangeLog addition: 2011-09-04 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el (byte-compile-output-file-form): * bytecomp.el (byte-compile-output-docform): Bind print-circle, print-continuous-numbering in these functions, now those variables are available. * lisp.el (forward-sexp): * lisp.el (backward-sexp): Recognise leading #N= as being part of an expression. tests/ChangeLog addition: 2011-09-04 Aidan Kehoe <kehoea@parhasard.net> * automated/lisp-reader-tests.el: * automated/lisp-tests.el (literal-with-uninterned): * automated/symbol-tests.el (foo): Test print-circle, for printing (mutually-)recursive and circular structures. Bind print-continuous-numbering where appropriate.

/* profile.c --- generate periodic events for profiling of Emacs Lisp code.
 Copyright (C) 1992, 1994 Free Software Foundation, Inc.
 Copyright (C) 2004 Ben Wing.

 Author: Boaz Ben-Zvi <boaz@lcs.mit.edu>

  This file is part of XEmacs.

  XEmacs 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 3 of the License, or (at your
  option) any later version.

  XEmacs 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 XEmacs.  If not, see <http://www.gnu.org/licenses/>. */

/* Synched up with: FSF 19.28. */
/* #### Not sure if this is needed for XEmacs. */

/**
 **  To be run as an emacs process. Input string that starts with:
 **    'z' -- resets the watch (to zero).
 **    'p' -- return time (on stdout) as string with format <sec>.<micro-sec>
 **    'q' -- exit.
 **
 **  abstraction : a stopwatch
 **  operations: reset_watch, get_time
 */
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include "../src/systime.h"

static struct timeval TV1, TV2;
static int watch_not_started = 1; /* flag */
static char time_string[30];

#ifdef WIN32_NATIVE
#include <sys/timeb.h>
/* Emulate gettimeofday (Ulrich Leodolter, 1/11/95).  */
void 
gettimeofday (struct timeval *tv, struct timezone *tz)
{
  struct _timeb tb;
  _ftime (&tb);

  tv->tv_sec = tb.time;
  tv->tv_usec = tb.millitm * 1000L;
  if (tz) 
    {
      tz->tz_minuteswest = tb.timezone;	/* minutes west of Greenwich  */
      tz->tz_dsttime = tb.dstflag;	/* type of dst correction  */
    }
}
#endif

/* Reset the stopwatch to zero.  */

static void
reset_watch (void)
{
  EMACS_GET_TIME (TV1);
  watch_not_started = 0;
}

/* This call returns the time since the last reset_watch call.  The time
   is returned as a string with the format  <seconds>.<micro-seconds> 
   If reset_watch was not called yet, exit.  */

static char *
get_time (void)
{
  if (watch_not_started)
    exit (1);  /* call reset_watch first ! */
  EMACS_GET_TIME (TV2);
  if (TV1.tv_usec > TV2.tv_usec)
    {
      TV2.tv_usec += 1000000;
      TV2.tv_sec--;
    }
  sprintf (time_string, "%lu.%06lu",
	  (unsigned long) TV2.tv_sec - TV1.tv_sec,
	  (unsigned long) TV2.tv_usec - TV1.tv_usec);
  return time_string;
}

int
main (int argc, char **argv)
{
  int c;
  while ((c = getchar ()) != EOF)
    {
      switch (c)
	{
	case 'z':
	  reset_watch ();
	  break;
	case 'p':
	  puts (get_time ());
	  break;
	case 'q':
	  exit (0);
	}
      /* Anything remaining on the line is ignored.  */
      while (c != '\n' && c != EOF)
	c = getchar ();
    }
  return 1;
}