data.c 94.9 KB
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/* Primitive operations on Lisp data types for GNU Emacs Lisp interpreter.
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   Copyright (C) 1985, 1986, 1988, 1993, 1994, 1995, 1997, 1998, 1999, 2000,
                 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
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This file is part of GNU Emacs.

GNU Emacs is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.

GNU Emacs 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 GNU Emacs; see the file COPYING.  If not, write to
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the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.  */
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#include <config.h>
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#include <signal.h>
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#include <stdio.h>
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#include "lisp.h"
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#include "puresize.h"
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#include "charset.h"
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#include "buffer.h"
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#include "keyboard.h"
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#include "frame.h"
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#include "syssignal.h"
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#ifdef STDC_HEADERS
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#include <float.h>
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#endif
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/* If IEEE_FLOATING_POINT isn't defined, default it from FLT_*. */
#ifndef IEEE_FLOATING_POINT
#if (FLT_RADIX == 2 && FLT_MANT_DIG == 24 \
     && FLT_MIN_EXP == -125 && FLT_MAX_EXP == 128)
#define IEEE_FLOATING_POINT 1
#else
#define IEEE_FLOATING_POINT 0
#endif
#endif

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/* Work around a problem that happens because math.h on hpux 7
   defines two static variables--which, in Emacs, are not really static,
   because `static' is defined as nothing.  The problem is that they are
   here, in floatfns.c, and in lread.c.
   These macros prevent the name conflict.  */
#if defined (HPUX) && !defined (HPUX8)
#define _MAXLDBL data_c_maxldbl
#define _NMAXLDBL data_c_nmaxldbl
#endif

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#include <math.h>

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#if !defined (atof)
extern double atof ();
#endif /* !atof */

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Lisp_Object Qnil, Qt, Qquote, Qlambda, Qsubr, Qunbound;
Lisp_Object Qerror_conditions, Qerror_message, Qtop_level;
Lisp_Object Qerror, Qquit, Qwrong_type_argument, Qargs_out_of_range;
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Lisp_Object Qvoid_variable, Qvoid_function, Qcyclic_function_indirection;
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Lisp_Object Qcyclic_variable_indirection, Qcircular_list;
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Lisp_Object Qsetting_constant, Qinvalid_read_syntax;
Lisp_Object Qinvalid_function, Qwrong_number_of_arguments, Qno_catch;
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Lisp_Object Qend_of_file, Qarith_error, Qmark_inactive;
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Lisp_Object Qbeginning_of_buffer, Qend_of_buffer, Qbuffer_read_only;
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Lisp_Object Qtext_read_only;
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Lisp_Object Qintegerp, Qnatnump, Qwholenump, Qsymbolp, Qlistp, Qconsp;
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Lisp_Object Qstringp, Qarrayp, Qsequencep, Qbufferp;
Lisp_Object Qchar_or_string_p, Qmarkerp, Qinteger_or_marker_p, Qvectorp;
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Lisp_Object Qbuffer_or_string_p, Qkeywordp;
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Lisp_Object Qboundp, Qfboundp;
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Lisp_Object Qchar_table_p, Qvector_or_char_table_p;
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Lisp_Object Qcdr;
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Lisp_Object Qad_advice_info, Qad_activate_internal;
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Lisp_Object Qrange_error, Qdomain_error, Qsingularity_error;
Lisp_Object Qoverflow_error, Qunderflow_error;

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Lisp_Object Qfloatp;
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Lisp_Object Qnumberp, Qnumber_or_marker_p;

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Lisp_Object Qinteger;
static Lisp_Object Qsymbol, Qstring, Qcons, Qmarker, Qoverlay;
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static Lisp_Object Qfloat, Qwindow_configuration, Qwindow;
Lisp_Object Qprocess;
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static Lisp_Object Qcompiled_function, Qbuffer, Qframe, Qvector;
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static Lisp_Object Qchar_table, Qbool_vector, Qhash_table;
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static Lisp_Object Qsubrp, Qmany, Qunevalled;
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static Lisp_Object swap_in_symval_forwarding P_ ((Lisp_Object, Lisp_Object));
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Lisp_Object Vmost_positive_fixnum, Vmost_negative_fixnum;
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void
circular_list_error (list)
     Lisp_Object list;
{
  Fsignal (Qcircular_list, list);
}


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Lisp_Object
wrong_type_argument (predicate, value)
     register Lisp_Object predicate, value;
{
  register Lisp_Object tem;
  do
    {
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      /* If VALUE is not even a valid Lisp object, abort here
	 where we can get a backtrace showing where it came from.  */
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      if ((unsigned int) XGCTYPE (value) >= Lisp_Type_Limit)
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	abort ();

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      value = Fsignal (Qwrong_type_argument, Fcons (predicate, Fcons (value, Qnil)));
      tem = call1 (predicate, value);
    }
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  while (NILP (tem));
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  return value;
}

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void
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pure_write_error ()
{
  error ("Attempt to modify read-only object");
}

void
args_out_of_range (a1, a2)
     Lisp_Object a1, a2;
{
  while (1)
    Fsignal (Qargs_out_of_range, Fcons (a1, Fcons (a2, Qnil)));
}

void
args_out_of_range_3 (a1, a2, a3)
     Lisp_Object a1, a2, a3;
{
  while (1)
    Fsignal (Qargs_out_of_range, Fcons (a1, Fcons (a2, Fcons (a3, Qnil))));
}

/* On some machines, XINT needs a temporary location.
   Here it is, in case it is needed.  */

int sign_extend_temp;

/* On a few machines, XINT can only be done by calling this.  */

int
sign_extend_lisp_int (num)
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     EMACS_INT num;
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{
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  if (num & (((EMACS_INT) 1) << (VALBITS - 1)))
    return num | (((EMACS_INT) (-1)) << VALBITS);
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  else
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    return num & ((((EMACS_INT) 1) << VALBITS) - 1);
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}

/* Data type predicates */

DEFUN ("eq", Feq, Seq, 2, 2, 0,
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       doc: /* Return t if the two args are the same Lisp object.  */)
     (obj1, obj2)
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     Lisp_Object obj1, obj2;
{
  if (EQ (obj1, obj2))
    return Qt;
  return Qnil;
}

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DEFUN ("null", Fnull, Snull, 1, 1, 0,
       doc: /* Return t if OBJECT is nil.  */)
     (object)
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     Lisp_Object object;
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{
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  if (NILP (object))
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    return Qt;
  return Qnil;
}

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DEFUN ("type-of", Ftype_of, Stype_of, 1, 1, 0,
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       doc: /* Return a symbol representing the type of OBJECT.
The symbol returned names the object's basic type;
for example, (type-of 1) returns `integer'.  */)
     (object)
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     Lisp_Object object;
{
  switch (XGCTYPE (object))
    {
    case Lisp_Int:
      return Qinteger;

    case Lisp_Symbol:
      return Qsymbol;

    case Lisp_String:
      return Qstring;

    case Lisp_Cons:
      return Qcons;

    case Lisp_Misc:
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      switch (XMISCTYPE (object))
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	{
	case Lisp_Misc_Marker:
	  return Qmarker;
	case Lisp_Misc_Overlay:
	  return Qoverlay;
	case Lisp_Misc_Float:
	  return Qfloat;
	}
      abort ();

    case Lisp_Vectorlike:
      if (GC_WINDOW_CONFIGURATIONP (object))
	return Qwindow_configuration;
      if (GC_PROCESSP (object))
	return Qprocess;
      if (GC_WINDOWP (object))
	return Qwindow;
      if (GC_SUBRP (object))
	return Qsubr;
      if (GC_COMPILEDP (object))
	return Qcompiled_function;
      if (GC_BUFFERP (object))
	return Qbuffer;
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      if (GC_CHAR_TABLE_P (object))
	return Qchar_table;
      if (GC_BOOL_VECTOR_P (object))
	return Qbool_vector;
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      if (GC_FRAMEP (object))
	return Qframe;
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      if (GC_HASH_TABLE_P (object))
	return Qhash_table;
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      return Qvector;

    case Lisp_Float:
      return Qfloat;

    default:
      abort ();
    }
}

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DEFUN ("consp", Fconsp, Sconsp, 1, 1, 0,
       doc: /* Return t if OBJECT is a cons cell.  */)
     (object)
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     Lisp_Object object;
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{
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  if (CONSP (object))
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    return Qt;
  return Qnil;
}

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DEFUN ("atom", Fatom, Satom, 1, 1, 0,
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       doc: /* Return t if OBJECT is not a cons cell.  This includes nil.  */)
     (object)
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     Lisp_Object object;
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{
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  if (CONSP (object))
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    return Qnil;
  return Qt;
}

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DEFUN ("listp", Flistp, Slistp, 1, 1, 0,
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       doc: /* Return t if OBJECT is a list, that is, a cons cell or nil.
Otherwise, return nil.  */)
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     (object)
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     Lisp_Object object;
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{
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  if (CONSP (object) || NILP (object))
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    return Qt;
  return Qnil;
}

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DEFUN ("nlistp", Fnlistp, Snlistp, 1, 1, 0,
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       doc: /* Return t if OBJECT is not a list.  Lists include nil.  */)
     (object)
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     Lisp_Object object;
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{
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  if (CONSP (object) || NILP (object))
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    return Qnil;
  return Qt;
}

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DEFUN ("symbolp", Fsymbolp, Ssymbolp, 1, 1, 0,
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       doc: /* Return t if OBJECT is a symbol.  */)
     (object)
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     Lisp_Object object;
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{
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  if (SYMBOLP (object))
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    return Qt;
  return Qnil;
}

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/* Define this in C to avoid unnecessarily consing up the symbol
   name.  */
DEFUN ("keywordp", Fkeywordp, Skeywordp, 1, 1, 0,
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       doc: /* Return t if OBJECT is a keyword.
This means that it is a symbol with a print name beginning with `:'
interned in the initial obarray.  */)
     (object)
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     Lisp_Object object;
{
  if (SYMBOLP (object)
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      && SREF (SYMBOL_NAME (object), 0) == ':'
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      && SYMBOL_INTERNED_IN_INITIAL_OBARRAY_P (object))
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    return Qt;
  return Qnil;
}

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DEFUN ("vectorp", Fvectorp, Svectorp, 1, 1, 0,
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       doc: /* Return t if OBJECT is a vector.  */)
     (object)
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     Lisp_Object object;
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{
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  if (VECTORP (object))
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    return Qt;
  return Qnil;
}

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DEFUN ("stringp", Fstringp, Sstringp, 1, 1, 0,
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       doc: /* Return t if OBJECT is a string.  */)
     (object)
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     Lisp_Object object;
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{
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  if (STRINGP (object))
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    return Qt;
  return Qnil;
}

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DEFUN ("multibyte-string-p", Fmultibyte_string_p, Smultibyte_string_p,
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       1, 1, 0,
       doc: /* Return t if OBJECT is a multibyte string.  */)
     (object)
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     Lisp_Object object;
{
  if (STRINGP (object) && STRING_MULTIBYTE (object))
    return Qt;
  return Qnil;
}

DEFUN ("char-table-p", Fchar_table_p, Schar_table_p, 1, 1, 0,
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       doc: /* Return t if OBJECT is a char-table.  */)
     (object)
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     Lisp_Object object;
{
  if (CHAR_TABLE_P (object))
    return Qt;
  return Qnil;
}

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DEFUN ("vector-or-char-table-p", Fvector_or_char_table_p,
       Svector_or_char_table_p, 1, 1, 0,
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       doc: /* Return t if OBJECT is a char-table or vector.  */)
     (object)
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     Lisp_Object object;
{
  if (VECTORP (object) || CHAR_TABLE_P (object))
    return Qt;
  return Qnil;
}

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DEFUN ("bool-vector-p", Fbool_vector_p, Sbool_vector_p, 1, 1, 0,
       doc: /* Return t if OBJECT is a bool-vector.  */)
     (object)
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     Lisp_Object object;
{
  if (BOOL_VECTOR_P (object))
    return Qt;
  return Qnil;
}

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DEFUN ("arrayp", Farrayp, Sarrayp, 1, 1, 0,
       doc: /* Return t if OBJECT is an array (string or vector).  */)
     (object)
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     Lisp_Object object;
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{
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  if (VECTORP (object) || STRINGP (object)
      || CHAR_TABLE_P (object) || BOOL_VECTOR_P (object))
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    return Qt;
  return Qnil;
}

DEFUN ("sequencep", Fsequencep, Ssequencep, 1, 1, 0,
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       doc: /* Return t if OBJECT is a sequence (list or array).  */)
     (object)
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     register Lisp_Object object;
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{
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  if (CONSP (object) || NILP (object) || VECTORP (object) || STRINGP (object)
      || CHAR_TABLE_P (object) || BOOL_VECTOR_P (object))
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    return Qt;
  return Qnil;
}

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DEFUN ("bufferp", Fbufferp, Sbufferp, 1, 1, 0,
       doc: /* Return t if OBJECT is an editor buffer.  */)
     (object)
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     Lisp_Object object;
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{
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  if (BUFFERP (object))
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    return Qt;
  return Qnil;
}

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DEFUN ("markerp", Fmarkerp, Smarkerp, 1, 1, 0,
       doc: /* Return t if OBJECT is a marker (editor pointer).  */)
     (object)
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     Lisp_Object object;
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{
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  if (MARKERP (object))
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    return Qt;
  return Qnil;
}

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DEFUN ("subrp", Fsubrp, Ssubrp, 1, 1, 0,
       doc: /* Return t if OBJECT is a built-in function.  */)
     (object)
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     Lisp_Object object;
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{
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  if (SUBRP (object))
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    return Qt;
  return Qnil;
}

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DEFUN ("byte-code-function-p", Fbyte_code_function_p, Sbyte_code_function_p,
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       1, 1, 0,
       doc: /* Return t if OBJECT is a byte-compiled function object.  */)
     (object)
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     Lisp_Object object;
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{
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  if (COMPILEDP (object))
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    return Qt;
  return Qnil;
}

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DEFUN ("char-or-string-p", Fchar_or_string_p, Schar_or_string_p, 1, 1, 0,
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       doc: /* Return t if OBJECT is a character (an integer) or a string.  */)
     (object)
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     register Lisp_Object object;
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{
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  if (INTEGERP (object) || STRINGP (object))
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    return Qt;
  return Qnil;
}

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DEFUN ("integerp", Fintegerp, Sintegerp, 1, 1, 0,
       doc: /* Return t if OBJECT is an integer.  */)
     (object)
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     Lisp_Object object;
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{
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  if (INTEGERP (object))
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    return Qt;
  return Qnil;
}

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DEFUN ("integer-or-marker-p", Finteger_or_marker_p, Sinteger_or_marker_p, 1, 1, 0,
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       doc: /* Return t if OBJECT is an integer or a marker (editor pointer).  */)
     (object)
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     register Lisp_Object object;
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{
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  if (MARKERP (object) || INTEGERP (object))
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    return Qt;
  return Qnil;
}

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DEFUN ("natnump", Fnatnump, Snatnump, 1, 1, 0,
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       doc: /* Return t if OBJECT is a nonnegative integer.  */)
     (object)
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     Lisp_Object object;
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{
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  if (NATNUMP (object))
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    return Qt;
  return Qnil;
}

DEFUN ("numberp", Fnumberp, Snumberp, 1, 1, 0,
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       doc: /* Return t if OBJECT is a number (floating point or integer).  */)
     (object)
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     Lisp_Object object;
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{
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  if (NUMBERP (object))
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    return Qt;
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  else
    return Qnil;
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}

DEFUN ("number-or-marker-p", Fnumber_or_marker_p,
       Snumber_or_marker_p, 1, 1, 0,
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       doc: /* Return t if OBJECT is a number or a marker.  */)
     (object)
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     Lisp_Object object;
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{
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  if (NUMBERP (object) || MARKERP (object))
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    return Qt;
  return Qnil;
}
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DEFUN ("floatp", Ffloatp, Sfloatp, 1, 1, 0,
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       doc: /* Return t if OBJECT is a floating point number.  */)
     (object)
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     Lisp_Object object;
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{
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  if (FLOATP (object))
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    return Qt;
  return Qnil;
}
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/* Extract and set components of lists */

DEFUN ("car", Fcar, Scar, 1, 1, 0,
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       doc: /* Return the car of LIST.  If arg is nil, return nil.
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Error if arg is not nil and not a cons cell.  See also `car-safe'.

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See Info node `(elisp)Cons Cells' for a discussion of related basic
Lisp concepts such as car, cdr, cons cell and list.  */)
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     (list)
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     register Lisp_Object list;
{
  while (1)
    {
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      if (CONSP (list))
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	return XCAR (list);
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      else if (EQ (list, Qnil))
	return Qnil;
      else
	list = wrong_type_argument (Qlistp, list);
    }
}

DEFUN ("car-safe", Fcar_safe, Scar_safe, 1, 1, 0,
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       doc: /* Return the car of OBJECT if it is a cons cell, or else nil.  */)
     (object)
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     Lisp_Object object;
{
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  if (CONSP (object))
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    return XCAR (object);
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  else
    return Qnil;
}

DEFUN ("cdr", Fcdr, Scdr, 1, 1, 0,
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       doc: /* Return the cdr of LIST.  If arg is nil, return nil.
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Error if arg is not nil and not a cons cell.  See also `cdr-safe'.

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See Info node `(elisp)Cons Cells' for a discussion of related basic
Lisp concepts such as cdr, car, cons cell and list.  */)
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     (list)
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     register Lisp_Object list;
{
  while (1)
    {
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      if (CONSP (list))
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	return XCDR (list);
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      else if (EQ (list, Qnil))
	return Qnil;
      else
	list = wrong_type_argument (Qlistp, list);
    }
}

DEFUN ("cdr-safe", Fcdr_safe, Scdr_safe, 1, 1, 0,
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       doc: /* Return the cdr of OBJECT if it is a cons cell, or else nil.  */)
     (object)
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     Lisp_Object object;
{
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  if (CONSP (object))
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    return XCDR (object);
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  else
    return Qnil;
}

DEFUN ("setcar", Fsetcar, Ssetcar, 2, 2, 0,
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       doc: /* Set the car of CELL to be NEWCAR.  Returns NEWCAR.  */)
     (cell, newcar)
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     register Lisp_Object cell, newcar;
{
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  if (!CONSP (cell))
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    cell = wrong_type_argument (Qconsp, cell);

  CHECK_IMPURE (cell);
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  XSETCAR (cell, newcar);
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  return newcar;
}

DEFUN ("setcdr", Fsetcdr, Ssetcdr, 2, 2, 0,
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       doc: /* Set the cdr of CELL to be NEWCDR.  Returns NEWCDR.  */)
     (cell, newcdr)
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     register Lisp_Object cell, newcdr;
{
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  if (!CONSP (cell))
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    cell = wrong_type_argument (Qconsp, cell);

  CHECK_IMPURE (cell);
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  XSETCDR (cell, newcdr);
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  return newcdr;
}

/* Extract and set components of symbols */

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DEFUN ("boundp", Fboundp, Sboundp, 1, 1, 0,
       doc: /* Return t if SYMBOL's value is not void.  */)
     (symbol)
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     register Lisp_Object symbol;
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{
  Lisp_Object valcontents;
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  CHECK_SYMBOL (symbol);
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  valcontents = SYMBOL_VALUE (symbol);
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  if (BUFFER_LOCAL_VALUEP (valcontents)
      || SOME_BUFFER_LOCAL_VALUEP (valcontents))
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    valcontents = swap_in_symval_forwarding (symbol, valcontents);
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  return (EQ (valcontents, Qunbound) ? Qnil : Qt);
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}

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DEFUN ("fboundp", Ffboundp, Sfboundp, 1, 1, 0,
       doc: /* Return t if SYMBOL's function definition is not void.  */)
     (symbol)
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     register Lisp_Object symbol;
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{
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  CHECK_SYMBOL (symbol);
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  return (EQ (XSYMBOL (symbol)->function, Qunbound) ? Qnil : Qt);
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}

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DEFUN ("makunbound", Fmakunbound, Smakunbound, 1, 1, 0,
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       doc: /* Make SYMBOL's value be void.
Return SYMBOL.  */)
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     (symbol)
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     register Lisp_Object symbol;
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{
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  CHECK_SYMBOL (symbol);
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  if (XSYMBOL (symbol)->constant)
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    return Fsignal (Qsetting_constant, Fcons (symbol, Qnil));
  Fset (symbol, Qunbound);
  return symbol;
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}

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DEFUN ("fmakunbound", Ffmakunbound, Sfmakunbound, 1, 1, 0,
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       doc: /* Make SYMBOL's function definition be void.
Return SYMBOL.  */)
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     (symbol)
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     register Lisp_Object symbol;
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{
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  CHECK_SYMBOL (symbol);
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  if (NILP (symbol) || EQ (symbol, Qt))
    return Fsignal (Qsetting_constant, Fcons (symbol, Qnil));
  XSYMBOL (symbol)->function = Qunbound;
  return symbol;
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}

DEFUN ("symbol-function", Fsymbol_function, Ssymbol_function, 1, 1, 0,
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       doc: /* Return SYMBOL's function definition.  Error if that is void.  */)
     (symbol)
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     register Lisp_Object symbol;
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{
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  CHECK_SYMBOL (symbol);
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  if (EQ (XSYMBOL (symbol)->function, Qunbound))
    return Fsignal (Qvoid_function, Fcons (symbol, Qnil));
  return XSYMBOL (symbol)->function;
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}

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DEFUN ("symbol-plist", Fsymbol_plist, Ssymbol_plist, 1, 1, 0,
       doc: /* Return SYMBOL's property list.  */)
     (symbol)
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     register Lisp_Object symbol;
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{
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  CHECK_SYMBOL (symbol);
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  return XSYMBOL (symbol)->plist;
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}

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DEFUN ("symbol-name", Fsymbol_name, Ssymbol_name, 1, 1, 0,
       doc: /* Return SYMBOL's name, a string.  */)
     (symbol)
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     register Lisp_Object symbol;
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{
  register Lisp_Object name;

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  CHECK_SYMBOL (symbol);
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  name = SYMBOL_NAME (symbol);
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  return name;
}

DEFUN ("fset", Ffset, Sfset, 2, 2, 0,
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       doc: /* Set SYMBOL's function definition to DEFINITION, and return DEFINITION.  */)
     (symbol, definition)
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     register Lisp_Object symbol, definition;
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{
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  CHECK_SYMBOL (symbol);
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  if (NILP (symbol) || EQ (symbol, Qt))
    return Fsignal (Qsetting_constant, Fcons (symbol, Qnil));
  if (!NILP (Vautoload_queue) && !EQ (XSYMBOL (symbol)->function, Qunbound))
    Vautoload_queue = Fcons (Fcons (symbol, XSYMBOL (symbol)->function),
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			     Vautoload_queue);
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  XSYMBOL (symbol)->function = definition;
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  /* Handle automatic advice activation */
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  if (CONSP (XSYMBOL (symbol)->plist) && !NILP (Fget (symbol, Qad_advice_info)))
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    {
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      call2 (Qad_activate_internal, symbol, Qnil);
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      definition = XSYMBOL (symbol)->function;
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    }
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  return definition;
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}

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extern Lisp_Object Qfunction_documentation;

DEFUN ("defalias", Fdefalias, Sdefalias, 2, 3, 0,
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       doc: /* Set SYMBOL's function definition to DEFINITION, and return DEFINITION.
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Associates the function with the current load file, if any.
The optional third argument DOCSTRING specifies the documentation string
for SYMBOL; if it is omitted or nil, SYMBOL uses the documentation string
determined by DEFINITION.  */)
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     (symbol, definition, docstring)
     register Lisp_Object symbol, definition, docstring;
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{
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  CHECK_SYMBOL (symbol);
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  if (CONSP (XSYMBOL (symbol)->function)
      && EQ (XCAR (XSYMBOL (symbol)->function), Qautoload))
    LOADHIST_ATTACH (Fcons (Qt, symbol));
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  definition = Ffset (symbol, definition);
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  LOADHIST_ATTACH (Fcons (Qdefun, symbol));
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  if (!NILP (docstring))
    Fput (symbol, Qfunction_documentation, docstring);
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  return definition;
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}

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DEFUN ("setplist", Fsetplist, Ssetplist, 2, 2, 0,
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       doc: /* Set SYMBOL's property list to NEWPLIST, and return NEWPLIST.  */)
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     (symbol, newplist)
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     register Lisp_Object symbol, newplist;
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{
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  CHECK_SYMBOL (symbol);
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  XSYMBOL (symbol)->plist = newplist;
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  return newplist;
}
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DEFUN ("subr-arity", Fsubr_arity, Ssubr_arity, 1, 1, 0,
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       doc: /* Return minimum and maximum number of args allowed for SUBR.
SUBR must be a built-in function.
The returned value is a pair (MIN . MAX).  MIN is the minimum number
of args.  MAX is the maximum number or the symbol `many', for a
function with `&rest' args, or `unevalled' for a special form.  */)
     (subr)
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     Lisp_Object subr;
{
  short minargs, maxargs;
  if (!SUBRP (subr))
    wrong_type_argument (Qsubrp, subr);
  minargs = XSUBR (subr)->min_args;
  maxargs = XSUBR (subr)->max_args;
  if (maxargs == MANY)
    return Fcons (make_number (minargs), Qmany);
  else if (maxargs == UNEVALLED)
    return Fcons (make_number (minargs), Qunevalled);
  else
    return Fcons (make_number (minargs), make_number (maxargs));
}

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DEFUN ("subr-name", Fsubr_name, Ssubr_name, 1, 1, 0,
       doc: /* Return name of subroutine SUBR.
SUBR must be a built-in function.  */)
     (subr)
     Lisp_Object subr;
{
  const char *name;
  if (!SUBRP (subr))
    wrong_type_argument (Qsubrp, subr);
  name = XSUBR (subr)->symbol_name;
  return make_string (name, strlen (name));
}

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DEFUN ("interactive-form", Finteractive_form, Sinteractive_form, 1, 1, 0,
       doc: /* Return the interactive form of CMD or nil if none.
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If CMD is not a command, the return value is nil.
Value, if non-nil, is a list \(interactive SPEC).  */)
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     (cmd)
     Lisp_Object cmd;
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{
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  Lisp_Object fun = indirect_function (cmd);

  if (SUBRP (fun))
    {
      if (XSUBR (fun)->prompt)
	return list2 (Qinteractive, build_string (XSUBR (fun)->prompt));
    }
  else if (COMPILEDP (fun))
    {
      if ((ASIZE (fun) & PSEUDOVECTOR_SIZE_MASK) > COMPILED_INTERACTIVE)
	return list2 (Qinteractive, AREF (fun, COMPILED_INTERACTIVE));
    }
  else if (CONSP (fun))
    {
      Lisp_Object funcar = XCAR (fun);
      if (EQ (funcar, Qlambda))
	return Fassq (Qinteractive, Fcdr (XCDR (fun)));
      else if (EQ (funcar, Qautoload))
	{
	  struct gcpro gcpro1;
	  GCPRO1 (cmd);
	  do_autoload (fun, cmd);
	  UNGCPRO;
	  return Finteractive_form (cmd);
	}
    }
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  return Qnil;
}

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/***********************************************************************
		Getting and Setting Values of Symbols
 ***********************************************************************/

/* Return the symbol holding SYMBOL's value.  Signal
   `cyclic-variable-indirection' if SYMBOL's chain of variable
   indirections contains a loop.  */

Lisp_Object
indirect_variable (symbol)
     Lisp_Object symbol;
{
  Lisp_Object tortoise, hare;

  hare = tortoise = symbol;

  while (XSYMBOL (hare)->indirect_variable)
    {
      hare = XSYMBOL (hare)->value;
      if (!XSYMBOL (hare)->indirect_variable)
	break;
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      hare = XSYMBOL (hare)->value;
      tortoise = XSYMBOL (tortoise)->value;

      if (EQ (hare, tortoise))
	Fsignal (Qcyclic_variable_indirection, Fcons (symbol, Qnil));
    }

  return hare;
}


DEFUN ("indirect-variable", Findirect_variable, Sindirect_variable, 1, 1, 0,
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       doc: /* Return the variable at the end of OBJECT's variable chain.
If OBJECT is a symbol, follow all variable indirections and return the final
variable.  If OBJECT is not a symbol, just return it.
Signal a cyclic-variable-indirection error if there is a loop in the
variable chain of symbols.  */)
     (object)
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     Lisp_Object object;
{
  if (SYMBOLP (object))
    object = indirect_variable (object);
  return object;
}

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/* Given the raw contents of a symbol value cell,
   return the Lisp value of the symbol.
   This does not handle buffer-local variables; use
   swap_in_symval_forwarding for that.  */

Lisp_Object
do_symval_forwarding (valcontents)
     register Lisp_Object valcontents;
{
  register Lisp_Object val;
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  int offset;
  if (MISCP (valcontents))
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    switch (XMISCTYPE (valcontents))
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      {
      case Lisp_Misc_Intfwd:
	XSETINT (val, *XINTFWD (valcontents)->intvar);
	return val;
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      case Lisp_Misc_Boolfwd:
	return (*XBOOLFWD (valcontents)->boolvar ? Qt : Qnil);
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      case Lisp_Misc_Objfwd:
	return *XOBJFWD (valcontents)->objvar;
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      case Lisp_Misc_Buffer_Objfwd:
	offset = XBUFFER_OBJFWD (valcontents)->offset;
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	return PER_BUFFER_VALUE (current_buffer, offset);
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      case Lisp_Misc_Kboard_Objfwd:
	offset = XKBOARD_OBJFWD (valcontents)->offset;
	return *(Lisp_Object *)(offset + (char *)current_kboard);
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      }
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  return valcontents;
}

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/* Store NEWVAL into SYMBOL, where VALCONTENTS is found in the value cell
   of SYMBOL.  If SYMBOL is buffer-local, VALCONTENTS should be the
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   buffer-independent contents of the value cell: forwarded just one
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   step past the buffer-localness.

   BUF non-zero means set the value in buffer BUF instead of the
   current buffer.  This only plays a role for per-buffer variables.  */
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void
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store_symval_forwarding (symbol, valcontents, newval, buf)
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     Lisp_Object symbol;
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     register Lisp_Object valcontents, newval;
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     struct buffer *buf;
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{
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  switch (SWITCH_ENUM_CAST (XTYPE (valcontents)))
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    {
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    case Lisp_Misc: