1/*    av.h
2 *
3 *    Copyright (C) 1991, 1992, 1993, 1995, 1996, 1997, 1998, 1999,
4 *    2000, 2001, 2002, by Larry Wall and others
5 *
6 *    You may distribute under the terms of either the GNU General Public
7 *    License or the Artistic License, as specified in the README file.
8 *
9 */
10
11struct xpvav {
12    char*	xav_array;      /* pointer to first array element */
13    SSize_t	xav_fill;       /* Index of last element present */
14    SSize_t	xav_max;        /* max index for which array has space */
15    IV		xof_off;	/* ptr is incremented by offset */
16    NV		xnv_nv;		/* numeric value, if any */
17    MAGIC*	xmg_magic;	/* magic for scalar array */
18    HV*		xmg_stash;	/* class package */
19
20    SV**	xav_alloc;	/* pointer to beginning of C array of SVs */
21    SV*		xav_arylen;
22    U8		xav_flags;
23};
24
25
26/* AVf_REAL is set for all AVs whose xav_array contents are refcounted.
27 * Some things like "@_" and the scratchpad list do not set this, to
28 * indicate that they are cheating (for efficiency) by not refcounting
29 * the AV's contents.
30 *
31 * AVf_REIFY is only meaningful on such "fake" AVs (i.e. where AVf_REAL
32 * is not set).  It indicates that the fake AV is capable of becoming
33 * real if the array needs to be modified in some way.  Functions that
34 * modify fake AVs check both flags to call av_reify() as appropriate.
35 *
36 * Note that the Perl stack and @DB::args have neither flag set. (Thus,
37 * items that go on the stack are never refcounted.)
38 *
39 * These internal details are subject to change any time.  AV
40 * manipulations external to perl should not care about any of this.
41 * GSAR 1999-09-10
42 */
43#define AVf_REAL 1	/* free old entries */
44#define AVf_REIFY 2	/* can become real */
45
46/* XXX this is not used anywhere */
47#define AVf_REUSED 4	/* got undeffed--don't turn old memory into SVs now */
48
49/*
50=head1 Handy Values
51
52=for apidoc AmU||Nullav
53Null AV pointer.
54
55=head1 Array Manipulation Functions
56
57=for apidoc Am|int|AvFILL|AV* av
58Same as C<av_len()>.  Deprecated, use C<av_len()> instead.
59
60=cut
61*/
62
63#define Nullav Null(AV*)
64
65#define AvARRAY(av)	((SV**)((XPVAV*)  SvANY(av))->xav_array)
66#define AvALLOC(av)	((XPVAV*)  SvANY(av))->xav_alloc
67#define AvMAX(av)	((XPVAV*)  SvANY(av))->xav_max
68#define AvFILLp(av)	((XPVAV*)  SvANY(av))->xav_fill
69#define AvARYLEN(av)	((XPVAV*)  SvANY(av))->xav_arylen
70#define AvFLAGS(av)	((XPVAV*)  SvANY(av))->xav_flags
71
72#define AvREAL(av)	(AvFLAGS(av) & AVf_REAL)
73#define AvREAL_on(av)	(AvFLAGS(av) |= AVf_REAL)
74#define AvREAL_off(av)	(AvFLAGS(av) &= ~AVf_REAL)
75#define AvREIFY(av)	(AvFLAGS(av) & AVf_REIFY)
76#define AvREIFY_on(av)	(AvFLAGS(av) |= AVf_REIFY)
77#define AvREIFY_off(av)	(AvFLAGS(av) &= ~AVf_REIFY)
78#define AvREUSED(av)	(AvFLAGS(av) & AVf_REUSED)
79#define AvREUSED_on(av)	(AvFLAGS(av) |= AVf_REUSED)
80#define AvREUSED_off(av) (AvFLAGS(av) &= ~AVf_REUSED)
81
82#define AvREALISH(av)	(AvFLAGS(av) & (AVf_REAL|AVf_REIFY))
83
84#define AvFILL(av)	((SvRMAGICAL((SV *) (av))) \
85			  ? mg_size((SV *) av) : AvFILLp(av))
86
87#define NEGATIVE_INDICES_VAR "NEGATIVE_INDICES"
88