-/* $RCSfile: array.c,v $$Revision: 4.1 $$Date: 92/08/07 17:18:22 $
+/* av.c
*
- * Copyright (c) 1991, Larry Wall
+ * Copyright (c) 1991-1997, Larry Wall
*
* You may distribute under the terms of either the GNU General Public
* License or the Artistic License, as specified in the README file.
*
- * $Log: array.c,v $
- * Revision 4.1 92/08/07 17:18:22 lwall
- * Stage 6 Snapshot
- *
- * Revision 4.0.1.3 92/06/08 11:45:05 lwall
- * patch20: Perl now distinguishes overlapped copies from non-overlapped
- *
- * Revision 4.0.1.2 91/11/05 16:00:14 lwall
- * patch11: random cleanup
- * patch11: passing non-existend array elements to subrouting caused core dump
- *
- * Revision 4.0.1.1 91/06/07 10:19:08 lwall
- * patch4: new copyright notice
- *
- * Revision 4.0 91/03/20 01:03:32 lwall
- * 4.0 baseline.
- *
+ */
+
+/*
+ * "...for the Entwives desired order, and plenty, and peace (by which they
+ * meant that things should remain where they had set them)." --Treebeard
*/
#include "EXTERN.h"
#include "perl.h"
+void
+av_reify(AV *av)
+{
+ I32 key;
+ SV* sv;
+
+ if (AvREAL(av))
+ return;
+#ifdef DEBUGGING
+ if (SvTIED_mg((SV*)av, 'P'))
+ warn("av_reify called on tied array");
+#endif
+ key = AvMAX(av) + 1;
+ while (key > AvFILLp(av) + 1)
+ AvARRAY(av)[--key] = &PL_sv_undef;
+ while (key) {
+ sv = AvARRAY(av)[--key];
+ assert(sv);
+ if (sv != &PL_sv_undef) {
+ dTHR;
+ (void)SvREFCNT_inc(sv);
+ }
+ }
+ key = AvARRAY(av) - AvALLOC(av);
+ while (key)
+ AvALLOC(av)[--key] = &PL_sv_undef;
+ AvREIFY_off(av);
+ AvREAL_on(av);
+}
+
+void
+av_extend(AV *av, I32 key)
+{
+ dTHR; /* only necessary if we have to extend stack */
+ MAGIC *mg;
+ if (mg = SvTIED_mg((SV*)av, 'P')) {
+ dSP;
+ ENTER;
+ SAVETMPS;
+ PUSHSTACKi(PERLSI_MAGIC);
+ PUSHMARK(SP);
+ EXTEND(SP,2);
+ PUSHs(SvTIED_obj((SV*)av, mg));
+ PUSHs(sv_2mortal(newSViv(key+1)));
+ PUTBACK;
+ perl_call_method("EXTEND", G_SCALAR|G_DISCARD);
+ POPSTACK;
+ FREETMPS;
+ LEAVE;
+ return;
+ }
+ if (key > AvMAX(av)) {
+ SV** ary;
+ I32 tmp;
+ I32 newmax;
+
+ if (AvALLOC(av) != AvARRAY(av)) {
+ ary = AvALLOC(av) + AvFILLp(av) + 1;
+ tmp = AvARRAY(av) - AvALLOC(av);
+ Move(AvARRAY(av), AvALLOC(av), AvFILLp(av)+1, SV*);
+ AvMAX(av) += tmp;
+ SvPVX(av) = (char*)AvALLOC(av);
+ if (AvREAL(av)) {
+ while (tmp)
+ ary[--tmp] = &PL_sv_undef;
+ }
+
+ if (key > AvMAX(av) - 10) {
+ newmax = key + AvMAX(av);
+ goto resize;
+ }
+ }
+ else {
+ if (AvALLOC(av)) {
+#ifndef STRANGE_MALLOC
+ U32 bytes;
+#endif
+
+#if defined(MYMALLOC) && !defined(PURIFY) && !defined(LEAKTEST)
+ newmax = malloced_size((void*)AvALLOC(av))/sizeof(SV*) - 1;
+
+ if (key <= newmax)
+ goto resized;
+#endif
+ newmax = key + AvMAX(av) / 5;
+ resize:
+#if defined(STRANGE_MALLOC) || defined(MYMALLOC)
+ Renew(AvALLOC(av),newmax+1, SV*);
+#else
+ bytes = (newmax + 1) * sizeof(SV*);
+#define MALLOC_OVERHEAD 16
+ tmp = MALLOC_OVERHEAD;
+ while (tmp - MALLOC_OVERHEAD < bytes)
+ tmp += tmp;
+ tmp -= MALLOC_OVERHEAD;
+ tmp /= sizeof(SV*);
+ assert(tmp > newmax);
+ newmax = tmp - 1;
+ New(2,ary, newmax+1, SV*);
+ Copy(AvALLOC(av), ary, AvMAX(av)+1, SV*);
+ if (AvMAX(av) > 64)
+ offer_nice_chunk(AvALLOC(av), (AvMAX(av)+1) * sizeof(SV*));
+ else
+ Safefree(AvALLOC(av));
+ AvALLOC(av) = ary;
+#endif
+ resized:
+ ary = AvALLOC(av) + AvMAX(av) + 1;
+ tmp = newmax - AvMAX(av);
+ if (av == PL_curstack) { /* Oops, grew stack (via av_store()?) */
+ PL_stack_sp = AvALLOC(av) + (PL_stack_sp - PL_stack_base);
+ PL_stack_base = AvALLOC(av);
+ PL_stack_max = PL_stack_base + newmax;
+ }
+ }
+ else {
+ newmax = key < 3 ? 3 : key;
+ New(2,AvALLOC(av), newmax+1, SV*);
+ ary = AvALLOC(av) + 1;
+ tmp = newmax;
+ AvALLOC(av)[0] = &PL_sv_undef; /* For the stacks */
+ }
+ if (AvREAL(av)) {
+ while (tmp)
+ ary[--tmp] = &PL_sv_undef;
+ }
+
+ SvPVX(av) = (char*)AvALLOC(av);
+ AvMAX(av) = newmax;
+ }
+ }
+}
+
SV**
-av_fetch(av,key,lval)
-register AV *av;
-I32 key;
-I32 lval;
+av_fetch(register AV *av, I32 key, I32 lval)
{
SV *sv;
+ if (!av)
+ return 0;
+
+ if (key < 0) {
+ key += AvFILL(av) + 1;
+ if (key < 0)
+ return 0;
+ }
+
if (SvRMAGICAL(av)) {
- if (mg_find((SV*)av,'P')) {
- if (key < 0)
- return 0;
+ if (mg_find((SV*)av,'P') || mg_find((SV*)av,'D')) {
+ dTHR;
sv = sv_newmortal();
mg_copy((SV*)av, sv, 0, key);
- if (!lval) {
- mg_get((SV*)sv);
- sv_unmagic(sv,'p');
- }
- Sv = sv;
- return &Sv;
+ PL_av_fetch_sv = sv;
+ return &PL_av_fetch_sv;
}
}
- if (key < 0 || key > AvFILL(av)) {
- if (key < 0) {
- key += AvFILL(av) + 1;
- if (key < 0)
- return 0;
- }
- else {
- if (!lval)
- return 0;
- if (AvREAL(av))
- sv = NEWSV(5,0);
- else
- sv = sv_newmortal();
- return av_store(av,key,sv);
- }
+ if (key > AvFILLp(av)) {
+ if (!lval)
+ return 0;
+ if (AvREALISH(av))
+ sv = NEWSV(5,0);
+ else
+ sv = sv_newmortal();
+ return av_store(av,key,sv);
}
- if (!AvARRAY(av)[key]) {
+ if (AvARRAY(av)[key] == &PL_sv_undef) {
+ emptyness:
if (lval) {
sv = NEWSV(6,0);
return av_store(av,key,sv);
}
return 0;
}
+ else if (AvREIFY(av)
+ && (!AvARRAY(av)[key] /* eg. @_ could have freed elts */
+ || SvTYPE(AvARRAY(av)[key]) == SVTYPEMASK)) {
+ AvARRAY(av)[key] = &PL_sv_undef; /* 1/2 reify */
+ goto emptyness;
+ }
return &AvARRAY(av)[key];
}
SV**
-av_store(av,key,val)
-register AV *av;
-I32 key;
-SV *val;
+av_store(register AV *av, I32 key, SV *val)
{
- I32 tmp;
SV** ary;
+ U32 fill;
+
+
+ if (!av)
+ return 0;
+ if (!val)
+ val = &PL_sv_undef;
if (key < 0) {
key += AvFILL(av) + 1;
return 0;
}
+ if (SvREADONLY(av) && key >= AvFILL(av))
+ croak(no_modify);
+
if (SvRMAGICAL(av)) {
if (mg_find((SV*)av,'P')) {
- mg_copy((SV*)av, val, 0, key);
+ if (val != &PL_sv_undef) {
+ mg_copy((SV*)av, val, 0, key);
+ }
return 0;
}
}
- if (key > AvMAX(av)) {
- I32 newmax;
-
- if (AvALLOC(av) != AvARRAY(av)) {
- tmp = AvARRAY(av) - AvALLOC(av);
- Move(AvARRAY(av), AvALLOC(av), AvMAX(av)+1, SV*);
- Zero(AvALLOC(av)+AvMAX(av)+1, tmp, SV*);
- AvMAX(av) += tmp;
- SvPVX(av) = (char*)(AvARRAY(av) - tmp);
- if (key > AvMAX(av) - 10) {
- newmax = key + AvMAX(av);
- goto resize;
- }
- }
- else {
- if (AvALLOC(av)) {
- newmax = key + AvMAX(av) / 5;
- resize:
- Renew(AvALLOC(av),newmax+1, SV*);
- Zero(&AvALLOC(av)[AvMAX(av)+1], newmax - AvMAX(av), SV*);
- }
- else {
- newmax = key < 4 ? 4 : key;
- Newz(2,AvALLOC(av), newmax+1, SV*);
- }
- SvPVX(av) = (char*)AvALLOC(av);
- AvMAX(av) = newmax;
- }
- }
+ if (!AvREAL(av) && AvREIFY(av))
+ av_reify(av);
+ if (key > AvMAX(av))
+ av_extend(av,key);
ary = AvARRAY(av);
- if (AvREAL(av)) {
- if (AvFILL(av) < key) {
- while (++AvFILL(av) < key) {
- if (ary[AvFILL(av)] != Nullsv) {
- SvREFCNT_dec(ary[AvFILL(av)]);
- ary[AvFILL(av)] = Nullsv;
- }
- }
+ if (AvFILLp(av) < key) {
+ if (!AvREAL(av)) {
+ dTHR;
+ if (av == PL_curstack && key > PL_stack_sp - PL_stack_base)
+ PL_stack_sp = PL_stack_base + key; /* XPUSH in disguise */
+ do
+ ary[++AvFILLp(av)] = &PL_sv_undef;
+ while (AvFILLp(av) < key);
}
- if (ary[key])
- SvREFCNT_dec(ary[key]);
+ AvFILLp(av) = key;
}
+ else if (AvREAL(av))
+ SvREFCNT_dec(ary[key]);
ary[key] = val;
if (SvSMAGICAL(av)) {
- MAGIC* mg = SvMAGIC(av);
- sv_magic(val, (SV*)av, tolower(mg->mg_type), 0, key);
+ if (val != &PL_sv_undef) {
+ MAGIC* mg = SvMAGIC(av);
+ sv_magic(val, (SV*)av, toLOWER(mg->mg_type), 0, key);
+ }
mg_set((SV*)av);
}
return &ary[key];
}
AV *
-newAV()
+newAV(void)
{
register AV *av;
- Newz(1,av,1,AV);
- SvREFCNT(av) = 1;
- sv_upgrade(av,SVt_PVAV);
+ av = (AV*)NEWSV(3,0);
+ sv_upgrade((SV *)av, SVt_PVAV);
AvREAL_on(av);
AvALLOC(av) = 0;
SvPVX(av) = 0;
- AvMAX(av) = AvFILL(av) = -1;
+ AvMAX(av) = AvFILLp(av) = -1;
return av;
}
AV *
-av_make(size,strp)
-register I32 size;
-register SV **strp;
+av_make(register I32 size, register SV **strp)
{
register AV *av;
register I32 i;
register SV** ary;
- Newz(3,av,1,AV);
- sv_upgrade(av,SVt_PVAV);
- New(4,ary,size+1,SV*);
- AvALLOC(av) = ary;
- Zero(ary,size,SV*);
- AvREAL_on(av);
- SvPVX(av) = (char*)ary;
- AvFILL(av) = size - 1;
- AvMAX(av) = size - 1;
- for (i = 0; i < size; i++) {
- if (*strp) {
+ av = (AV*)NEWSV(8,0);
+ sv_upgrade((SV *) av,SVt_PVAV);
+ AvFLAGS(av) = AVf_REAL;
+ if (size) { /* `defined' was returning undef for size==0 anyway. */
+ New(4,ary,size,SV*);
+ AvALLOC(av) = ary;
+ SvPVX(av) = (char*)ary;
+ AvFILLp(av) = size - 1;
+ AvMAX(av) = size - 1;
+ for (i = 0; i < size; i++) {
+ assert (*strp);
ary[i] = NEWSV(7,0);
sv_setsv(ary[i], *strp);
+ strp++;
}
- strp++;
}
- SvOK_on(av);
return av;
}
AV *
-av_fake(size,strp)
-register I32 size;
-register SV **strp;
+av_fake(register I32 size, register SV **strp)
{
register AV *av;
register SV** ary;
- Newz(3,av,1,AV);
- SvREFCNT(av) = 1;
- sv_upgrade(av,SVt_PVAV);
+ av = (AV*)NEWSV(9,0);
+ sv_upgrade((SV *)av, SVt_PVAV);
New(4,ary,size+1,SV*);
AvALLOC(av) = ary;
Copy(strp,ary,size,SV*);
- AvREAL_off(av);
+ AvFLAGS(av) = AVf_REIFY;
SvPVX(av) = (char*)ary;
- AvFILL(av) = size - 1;
+ AvFILLp(av) = size - 1;
AvMAX(av) = size - 1;
while (size--) {
- if (*strp)
- SvTEMP_off(*strp);
+ assert (*strp);
+ SvTEMP_off(*strp);
strp++;
}
- SvOK_on(av);
return av;
}
void
-av_clear(av)
-register AV *av;
+av_clear(register AV *av)
{
register I32 key;
+ SV** ary;
- if (!av || !AvREAL(av) || AvMAX(av) < 0)
+#ifdef DEBUGGING
+ if (SvREFCNT(av) <= 0) {
+ warn("Attempt to clear deleted array");
+ }
+#endif
+ if (!av)
return;
/*SUPPRESS 560*/
+
+ if (SvREADONLY(av))
+ croak(no_modify);
+
+ /* Give any tie a chance to cleanup first */
+ if (SvRMAGICAL(av))
+ mg_clear((SV*)av);
+
+ if (AvMAX(av) < 0)
+ return;
+
+ if (AvREAL(av)) {
+ ary = AvARRAY(av);
+ key = AvFILLp(av) + 1;
+ while (key) {
+ SvREFCNT_dec(ary[--key]);
+ ary[key] = &PL_sv_undef;
+ }
+ }
if (key = AvARRAY(av) - AvALLOC(av)) {
AvMAX(av) += key;
- SvPVX(av) = (char*)(AvARRAY(av) - key);
+ SvPVX(av) = (char*)AvALLOC(av);
}
- for (key = 0; key <= AvMAX(av); key++)
- SvREFCNT_dec(AvARRAY(av)[key]);
- AvFILL(av) = -1;
- Zero(AvARRAY(av), AvMAX(av)+1, SV*);
+ AvFILLp(av) = -1;
+
}
void
-av_undef(av)
-register AV *av;
+av_undef(register AV *av)
{
register I32 key;
if (!av)
return;
/*SUPPRESS 560*/
- if (key = AvARRAY(av) - AvALLOC(av)) {
- AvMAX(av) += key;
- SvPVX(av) = (char*)(AvARRAY(av) - key);
- }
+
+ /* Give any tie a chance to cleanup first */
+ if (SvTIED_mg((SV*)av, 'P'))
+ av_fill(av, -1); /* mg_clear() ? */
+
if (AvREAL(av)) {
- for (key = 0; key <= AvMAX(av); key++)
- SvREFCNT_dec(AvARRAY(av)[key]);
+ key = AvFILLp(av) + 1;
+ while (key)
+ SvREFCNT_dec(AvARRAY(av)[--key]);
}
Safefree(AvALLOC(av));
AvALLOC(av) = 0;
SvPVX(av) = 0;
- AvMAX(av) = AvFILL(av) = -1;
+ AvMAX(av) = AvFILLp(av) = -1;
+ if (AvARYLEN(av)) {
+ SvREFCNT_dec(AvARYLEN(av));
+ AvARYLEN(av) = 0;
+ }
}
void
-av_free(av)
-AV *av;
-{
- av_undef(av);
- Safefree(av);
-}
+av_push(register AV *av, SV *val)
+{
+ MAGIC *mg;
+ if (!av)
+ return;
+ if (SvREADONLY(av))
+ croak(no_modify);
-bool
-av_push(av,val)
-register AV *av;
-SV *val;
-{
- return av_store(av,++(AvFILL(av)),val) != 0;
+ if (mg = SvTIED_mg((SV*)av, 'P')) {
+ dSP;
+ PUSHSTACKi(PERLSI_MAGIC);
+ PUSHMARK(SP);
+ EXTEND(SP,2);
+ PUSHs(SvTIED_obj((SV*)av, mg));
+ PUSHs(val);
+ PUTBACK;
+ ENTER;
+ perl_call_method("PUSH", G_SCALAR|G_DISCARD);
+ LEAVE;
+ POPSTACK;
+ return;
+ }
+ av_store(av,AvFILLp(av)+1,val);
}
SV *
-av_pop(av)
-register AV *av;
+av_pop(register AV *av)
{
SV *retval;
+ MAGIC* mg;
- if (AvFILL(av) < 0)
- return Nullsv;
- retval = AvARRAY(av)[AvFILL(av)];
- AvARRAY(av)[AvFILL(av)--] = Nullsv;
+ if (!av || AvFILL(av) < 0)
+ return &PL_sv_undef;
+ if (SvREADONLY(av))
+ croak(no_modify);
+ if (mg = SvTIED_mg((SV*)av, 'P')) {
+ dSP;
+ PUSHSTACKi(PERLSI_MAGIC);
+ PUSHMARK(SP);
+ XPUSHs(SvTIED_obj((SV*)av, mg));
+ PUTBACK;
+ ENTER;
+ if (perl_call_method("POP", G_SCALAR)) {
+ retval = newSVsv(*PL_stack_sp--);
+ } else {
+ retval = &PL_sv_undef;
+ }
+ LEAVE;
+ POPSTACK;
+ return retval;
+ }
+ retval = AvARRAY(av)[AvFILLp(av)];
+ AvARRAY(av)[AvFILLp(av)--] = &PL_sv_undef;
if (SvSMAGICAL(av))
mg_set((SV*)av);
return retval;
}
void
-av_popnulls(av)
-register AV *av;
-{
- register I32 fill = AvFILL(av);
-
- while (fill >= 0 && !AvARRAY(av)[fill])
- fill--;
- AvFILL(av) = fill;
-}
-
-void
-av_unshift(av,num)
-register AV *av;
-register I32 num;
+av_unshift(register AV *av, register I32 num)
{
register I32 i;
- register SV **sstr,**dstr;
+ register SV **ary;
+ MAGIC* mg;
- if (num <= 0)
+ if (!av || num <= 0)
return;
- if (AvARRAY(av) - AvALLOC(av) >= num) {
- AvMAX(av) += num;
- AvFILL(av) += num;
- while (num--) {
- SvPVX(av) = (char*)(AvARRAY(av) - 1);
- *AvARRAY(av) = Nullsv;
+ if (SvREADONLY(av))
+ croak(no_modify);
+
+ if (mg = SvTIED_mg((SV*)av, 'P')) {
+ dSP;
+ PUSHSTACKi(PERLSI_MAGIC);
+ PUSHMARK(SP);
+ EXTEND(SP,1+num);
+ PUSHs(SvTIED_obj((SV*)av, mg));
+ while (num-- > 0) {
+ PUSHs(&PL_sv_undef);
}
+ PUTBACK;
+ ENTER;
+ perl_call_method("UNSHIFT", G_SCALAR|G_DISCARD);
+ LEAVE;
+ POPSTACK;
+ return;
}
- else {
- (void)av_store(av,AvFILL(av)+num,(SV*)0); /* maybe extend array */
- dstr = AvARRAY(av) + AvFILL(av);
- sstr = dstr - num;
-#ifdef BUGGY_MSC5
- # pragma loop_opt(off) /* don't loop-optimize the following code */
-#endif /* BUGGY_MSC5 */
- for (i = AvFILL(av) - num; i >= 0; i--) {
- *dstr-- = *sstr--;
-#ifdef BUGGY_MSC5
- # pragma loop_opt() /* loop-optimization back to command-line setting */
-#endif /* BUGGY_MSC5 */
- }
- Zero(AvARRAY(av), num, SV*);
+
+ if (!AvREAL(av) && AvREIFY(av))
+ av_reify(av);
+ i = AvARRAY(av) - AvALLOC(av);
+ if (i) {
+ if (i > num)
+ i = num;
+ num -= i;
+
+ AvMAX(av) += i;
+ AvFILLp(av) += i;
+ SvPVX(av) = (char*)(AvARRAY(av) - i);
+ }
+ if (num) {
+ i = AvFILLp(av);
+ av_extend(av, i + num);
+ AvFILLp(av) += num;
+ ary = AvARRAY(av);
+ Move(ary, ary + num, i + 1, SV*);
+ do {
+ ary[--num] = &PL_sv_undef;
+ } while (num);
}
}
SV *
-av_shift(av)
-register AV *av;
+av_shift(register AV *av)
{
SV *retval;
+ MAGIC* mg;
- if (AvFILL(av) < 0)
- return Nullsv;
+ if (!av || AvFILL(av) < 0)
+ return &PL_sv_undef;
+ if (SvREADONLY(av))
+ croak(no_modify);
+ if (mg = SvTIED_mg((SV*)av, 'P')) {
+ dSP;
+ PUSHSTACKi(PERLSI_MAGIC);
+ PUSHMARK(SP);
+ XPUSHs(SvTIED_obj((SV*)av, mg));
+ PUTBACK;
+ ENTER;
+ if (perl_call_method("SHIFT", G_SCALAR)) {
+ retval = newSVsv(*PL_stack_sp--);
+ } else {
+ retval = &PL_sv_undef;
+ }
+ LEAVE;
+ POPSTACK;
+ return retval;
+ }
retval = *AvARRAY(av);
- *AvARRAY(av) = Nullsv;
+ if (AvREAL(av))
+ *AvARRAY(av) = &PL_sv_undef;
SvPVX(av) = (char*)(AvARRAY(av) + 1);
AvMAX(av)--;
- AvFILL(av)--;
+ AvFILLp(av)--;
if (SvSMAGICAL(av))
mg_set((SV*)av);
return retval;
}
I32
-av_len(av)
-register AV *av;
+av_len(register AV *av)
{
return AvFILL(av);
}
void
-av_fill(av, fill)
-register AV *av;
-I32 fill;
+av_fill(register AV *av, I32 fill)
{
+ MAGIC *mg;
+ if (!av)
+ croak("panic: null array");
if (fill < 0)
fill = -1;
+ if (mg = SvTIED_mg((SV*)av, 'P')) {
+ dSP;
+ ENTER;
+ SAVETMPS;
+ PUSHSTACKi(PERLSI_MAGIC);
+ PUSHMARK(SP);
+ EXTEND(SP,2);
+ PUSHs(SvTIED_obj((SV*)av, mg));
+ PUSHs(sv_2mortal(newSViv(fill+1)));
+ PUTBACK;
+ perl_call_method("STORESIZE", G_SCALAR|G_DISCARD);
+ POPSTACK;
+ FREETMPS;
+ LEAVE;
+ return;
+ }
if (fill <= AvMAX(av)) {
- AvFILL(av) = fill;
+ I32 key = AvFILLp(av);
+ SV** ary = AvARRAY(av);
+
+ if (AvREAL(av)) {
+ while (key > fill) {
+ SvREFCNT_dec(ary[key]);
+ ary[key--] = &PL_sv_undef;
+ }
+ }
+ else {
+ while (key < fill)
+ ary[++key] = &PL_sv_undef;
+ }
+
+ AvFILLp(av) = fill;
if (SvSMAGICAL(av))
mg_set((SV*)av);
}
- else {
- AvFILL(av) = fill - 1; /* don't clobber in-between values */
- (void)av_store(av,fill,Nullsv);
+ else
+ (void)av_store(av,fill,&PL_sv_undef);
+}
+
+
+/* AVHV: Support for treating arrays as if they were hashes. The
+ * first element of the array should be a hash reference that maps
+ * hash keys to array indices.
+ */
+
+STATIC I32
+avhv_index_sv(SV* sv)
+{
+ I32 index = SvIV(sv);
+ if (index < 1)
+ croak("Bad index while coercing array into hash");
+ return index;
+}
+
+HV*
+avhv_keys(AV *av)
+{
+ SV **keysp = av_fetch(av, 0, FALSE);
+ if (keysp) {
+ SV *sv = *keysp;
+ if (SvGMAGICAL(sv))
+ mg_get(sv);
+ if (SvROK(sv)) {
+ sv = SvRV(sv);
+ if (SvTYPE(sv) == SVt_PVHV)
+ return (HV*)sv;
+ }
}
+ croak("Can't coerce array into hash");
+ return Nullhv;
+}
+
+SV**
+avhv_fetch_ent(AV *av, SV *keysv, I32 lval, U32 hash)
+{
+ SV **indsvp;
+ HV *keys = avhv_keys(av);
+ HE *he;
+
+ he = hv_fetch_ent(keys, keysv, FALSE, hash);
+ if (!he)
+ croak("No such array field");
+ return av_fetch(av, avhv_index_sv(HeVAL(he)), lval);
+}
+
+bool
+avhv_exists_ent(AV *av, SV *keysv, U32 hash)
+{
+ HV *keys = avhv_keys(av);
+ return hv_exists_ent(keys, keysv, hash);
+}
+
+HE *
+avhv_iternext(AV *av)
+{
+ HV *keys = avhv_keys(av);
+ return hv_iternext(keys);
+}
+
+SV *
+avhv_iterval(AV *av, register HE *entry)
+{
+ SV *sv = hv_iterval(avhv_keys(av), entry);
+ return *av_fetch(av, avhv_index_sv(sv), TRUE);
}