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Negative subscripts optionally passed to tied array methods
[perl5.git] / av.h
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a0d0e21e 1/* av.h
79072805 2 *
be3c0a43 3 * Copyright (c) 1991-2002, Larry Wall
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4 *
5 * You may distribute under the terms of either the GNU General Public
6 * License or the Artistic License, as specified in the README file.
7 *
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8 */
9
10struct xpvav {
ff0cee69 11 char* xav_array; /* pointer to first array element */
93965878 12 SSize_t xav_fill; /* Index of last element present */
d18c6117 13 SSize_t xav_max; /* max index for which array has space */
a0d0e21e 14 IV xof_off; /* ptr is incremented by offset */
65202027 15 NV xnv_nv; /* numeric value, if any */
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16 MAGIC* xmg_magic; /* magic for scalar array */
17 HV* xmg_stash; /* class package */
18
2fc34c7b 19 SV** xav_alloc; /* pointer to beginning of C array of SVs */
79072805 20 SV* xav_arylen;
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21 U8 xav_flags;
22};
23
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24
25/* AVf_REAL is set for all AVs whose xav_array contents are refcounted.
26 * Some things like "@_" and the scratchpad list do not set this, to
27 * indicate that they are cheating (for efficiency) by not refcounting
28 * the AV's contents.
29 *
30 * AVf_REIFY is only meaningful on such "fake" AVs (i.e. where AVf_REAL
31 * is not set). It indicates that the fake AV is capable of becoming
32 * real if the array needs to be modified in some way. Functions that
33 * modify fake AVs check both flags to call av_reify() as appropriate.
34 *
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35 * Note that the Perl stack and @DB::args have neither flag set. (Thus,
36 * items that go on the stack are never refcounted.)
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37 *
38 * These internal details are subject to change any time. AV
39 * manipulations external to perl should not care about any of this.
40 * GSAR 1999-09-10
41 */
79072805 42#define AVf_REAL 1 /* free old entries */
a0d0e21e 43#define AVf_REIFY 2 /* can become real */
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44
45/* XXX this is not used anywhere */
4633a7c4 46#define AVf_REUSED 4 /* got undeffed--don't turn old memory into SVs now */
79072805 47
954c1994 48/*
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49=head1 Handy Values
50
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51=for apidoc AmU||Nullav
52Null AV pointer.
53
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54=head1 Array Manipulation Functions
55
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56=for apidoc Am|int|AvFILL|AV* av
57Same as C<av_len()>. Deprecated, use C<av_len()> instead.
58
59=cut
60*/
61
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62#define Nullav Null(AV*)
63
463ee0b2 64#define AvARRAY(av) ((SV**)((XPVAV*) SvANY(av))->xav_array)
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65#define AvALLOC(av) ((XPVAV*) SvANY(av))->xav_alloc
66#define AvMAX(av) ((XPVAV*) SvANY(av))->xav_max
93965878 67#define AvFILLp(av) ((XPVAV*) SvANY(av))->xav_fill
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68#define AvARYLEN(av) ((XPVAV*) SvANY(av))->xav_arylen
69#define AvFLAGS(av) ((XPVAV*) SvANY(av))->xav_flags
70
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71#define AvREAL(av) (AvFLAGS(av) & AVf_REAL)
72#define AvREAL_on(av) (AvFLAGS(av) |= AVf_REAL)
73#define AvREAL_off(av) (AvFLAGS(av) &= ~AVf_REAL)
74#define AvREIFY(av) (AvFLAGS(av) & AVf_REIFY)
75#define AvREIFY_on(av) (AvFLAGS(av) |= AVf_REIFY)
76#define AvREIFY_off(av) (AvFLAGS(av) &= ~AVf_REIFY)
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77#define AvREUSED(av) (AvFLAGS(av) & AVf_REUSED)
78#define AvREUSED_on(av) (AvFLAGS(av) |= AVf_REUSED)
79#define AvREUSED_off(av) (AvFLAGS(av) &= ~AVf_REUSED)
a0d0e21e 80
0a5de7f0 81#define AvREALISH(av) (AvFLAGS(av) & (AVf_REAL|AVf_REIFY))
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82
83#define AvFILL(av) ((SvRMAGICAL((SV *) (av))) \
a60c0954 84 ? mg_size((SV *) av) : AvFILLp(av))
a0d0e21e 85
6f12eb6d 86#define NEGATIVE_INDICES_VAR "NEGATIVE_INDICES"