X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/38a1ac3f7341206073b47f38b6bdb094f3f50352..d61e7a0a162a2eb170aec7221bbb3cac17b313f1:/av.c

diff --git a/av.c b/av.c
index 6b4c03d..af8296a 100644
--- a/av.c
+++ b/av.c
@@ -1,6 +1,6 @@
 /*    av.c
  *
- *    Copyright (c) 1991-1997, Larry Wall
+ *    Copyright (c) 1991-1999, 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.
@@ -13,51 +13,74 @@
  */
 
 #include "EXTERN.h"
+#define PERL_IN_AV_C
 #include "perl.h"
 
-static void	av_reify _((AV* av));
-
-static void
-av_reify(av)
-AV* av;
+void
+Perl_av_reify(pTHX_ AV *av)
 {
     I32 key;
     SV* sv;
-    
+
+    if (AvREAL(av))
+	return;
+#ifdef DEBUGGING
+    if (SvTIED_mg((SV*)av, 'P') && ckWARN_d(WARN_DEBUGGING))
+	Perl_warner(aTHX_ WARN_DEBUGGING, "av_reify called on tied array");
+#endif
     key = AvMAX(av) + 1;
-    while (key > AvFILL(av) + 1)
-	AvARRAY(av)[--key] = &sv_undef;
+    while (key > AvFILLp(av) + 1)
+	AvARRAY(av)[--key] = &PL_sv_undef;
     while (key) {
 	sv = AvARRAY(av)[--key];
 	assert(sv);
-	if (sv != &sv_undef)
+	if (sv != &PL_sv_undef) {
+	    dTHR;
 	    (void)SvREFCNT_inc(sv);
+	}
     }
     key = AvARRAY(av) - AvALLOC(av);
     while (key)
-	AvALLOC(av)[--key] = &sv_undef;
+	AvALLOC(av)[--key] = &PL_sv_undef;
+    AvREIFY_off(av);
     AvREAL_on(av);
 }
 
 void
-av_extend(av,key)
-AV *av;
-I32 key;
+Perl_av_extend(pTHX_ 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;
+	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) + AvFILL(av) + 1;
+	    ary = AvALLOC(av) + AvFILLp(av) + 1;
 	    tmp = AvARRAY(av) - AvALLOC(av);
-	    Move(AvARRAY(av), AvALLOC(av), AvFILL(av)+1, SV*);
+	    Move(AvARRAY(av), AvALLOC(av), AvFILLp(av)+1, SV*);
 	    AvMAX(av) += tmp;
 	    SvPVX(av) = (char*)AvALLOC(av);
 	    if (AvREAL(av)) {
 		while (tmp)
-		    ary[--tmp] = &sv_undef;
+		    ary[--tmp] = &PL_sv_undef;
 	    }
 	    
 	    if (key > AvMAX(av) - 10) {
@@ -68,51 +91,58 @@ I32 key;
 	else {
 	    if (AvALLOC(av)) {
 #ifndef STRANGE_MALLOC
-		U32 bytes;
+		MEM_SIZE bytes;
+		IV itmp;
 #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:
-#ifdef STRANGE_MALLOC
+#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;
+		itmp = MALLOC_OVERHEAD;
+		while (itmp - MALLOC_OVERHEAD < bytes)
+		    itmp += itmp;
+		itmp -= MALLOC_OVERHEAD;
+		itmp /= sizeof(SV*);
+		assert(itmp > newmax);
+		newmax = itmp - 1;
+		assert(newmax >= AvMAX(av));
 		New(2,ary, newmax+1, SV*);
 		Copy(AvALLOC(av), ary, AvMAX(av)+1, SV*);
-		if (AvMAX(av) > 64 && !nice_chunk) {
-		    nice_chunk = (char*)AvALLOC(av);
-		    nice_chunk_size = (AvMAX(av) + 1) * sizeof(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 == curstack) {	/* Oops, grew stack (via av_store()?) */
-		    stack_sp = AvALLOC(av) + (stack_sp - stack_base);
-		    stack_base = AvALLOC(av);
-		    stack_max = stack_base + newmax;
+		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 < 4 ? 4 : key;
+		newmax = key < 3 ? 3 : key;
 		New(2,AvALLOC(av), newmax+1, SV*);
 		ary = AvALLOC(av) + 1;
 		tmp = newmax;
-		AvALLOC(av)[0] = &sv_undef;	/* For the stacks */
+		AvALLOC(av)[0] = &PL_sv_undef;	/* For the stacks */
 	    }
 	    if (AvREAL(av)) {
 		while (tmp)
-		    ary[--tmp] = &sv_undef;
+		    ary[--tmp] = &PL_sv_undef;
 	    }
 	    
 	    SvPVX(av) = (char*)AvALLOC(av);
@@ -122,40 +152,36 @@ I32 key;
 }
 
 SV**
-av_fetch(av,key,lval)
-register AV *av;
-I32 key;
-I32 lval;
+Perl_av_fetch(pTHX_ 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 (mg_find((SV*)av,'P') || mg_find((SV*)av,'D')) {
+	    dTHR;
 	    sv = sv_newmortal();
 	    mg_copy((SV*)av, sv, 0, key);
-	    Sv = sv;
-	    return &Sv;
+	    PL_av_fetch_sv = sv;
+	    return &PL_av_fetch_sv;
 	}
     }
 
-    if (key < 0) {
-	key += AvFILL(av) + 1;
-	if (key < 0)
-	    return 0;
-    }
-    else if (key > AvFILL(av)) {
+    if (key > AvFILLp(av)) {
 	if (!lval)
 	    return 0;
-	if (AvREALISH(av))
-	    sv = NEWSV(5,0);
-	else
-	    sv = sv_newmortal();
+	sv = NEWSV(5,0);
 	return av_store(av,key,sv);
     }
-    if (AvARRAY(av)[key] == &sv_undef) {
+    if (AvARRAY(av)[key] == &PL_sv_undef) {
     emptyness:
 	if (lval) {
 	    sv = NEWSV(6,0);
@@ -166,60 +192,63 @@ I32 lval;
     else if (AvREIFY(av)
 	     && (!AvARRAY(av)[key]	/* eg. @_ could have freed elts */
 		 || SvTYPE(AvARRAY(av)[key]) == SVTYPEMASK)) {
-	AvARRAY(av)[key] = &sv_undef;	/* 1/2 reify */
+	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;
+Perl_av_store(pTHX_ register AV *av, I32 key, SV *val)
 {
     SV** ary;
+    U32  fill;
+
 
     if (!av)
 	return 0;
     if (!val)
-	val = &sv_undef;
+	val = &PL_sv_undef;
+
+    if (key < 0) {
+	key += AvFILL(av) + 1;
+	if (key < 0)
+	    return 0;
+    }
+
+    if (SvREADONLY(av) && key >= AvFILL(av))
+	Perl_croak(aTHX_ PL_no_modify);
 
     if (SvRMAGICAL(av)) {
 	if (mg_find((SV*)av,'P')) {
-	    if (val != &sv_undef)
+	    if (val != &PL_sv_undef) {
 		mg_copy((SV*)av, val, 0, key);
+	    }
 	    return 0;
 	}
     }
 
-    if (key < 0) {
-	key += AvFILL(av) + 1;
-	if (key < 0)
-	    return 0;
-    }
-    if (SvREADONLY(av) && key >= AvFILL(av))
-	croak(no_modify);
     if (!AvREAL(av) && AvREIFY(av))
 	av_reify(av);
     if (key > AvMAX(av))
 	av_extend(av,key);
     ary = AvARRAY(av);
-    if (AvFILL(av) < key) {
+    if (AvFILLp(av) < key) {
 	if (!AvREAL(av)) {
-	    if (av == curstack && key > stack_sp - stack_base)
-		stack_sp = stack_base + key;	/* XPUSH in disguise */
+	    dTHR;
+	    if (av == PL_curstack && key > PL_stack_sp - PL_stack_base)
+		PL_stack_sp = PL_stack_base + key;	/* XPUSH in disguise */
 	    do
-		ary[++AvFILL(av)] = &sv_undef;
-	    while (AvFILL(av) < key);
+		ary[++AvFILLp(av)] = &PL_sv_undef;
+	    while (AvFILLp(av) < key);
 	}
-	AvFILL(av) = key;
+	AvFILLp(av) = key;
     }
     else if (AvREAL(av))
 	SvREFCNT_dec(ary[key]);
     ary[key] = val;
     if (SvSMAGICAL(av)) {
-	if (val != &sv_undef) {
+	if (val != &PL_sv_undef) {
 	    MAGIC* mg = SvMAGIC(av);
 	    sv_magic(val, (SV*)av, toLOWER(mg->mg_type), 0, key);
 	}
@@ -229,7 +258,7 @@ SV *val;
 }
 
 AV *
-newAV()
+Perl_newAV(pTHX)
 {
     register AV *av;
 
@@ -238,14 +267,12 @@ newAV()
     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;
+Perl_av_make(pTHX_ register I32 size, register SV **strp)
 {
     register AV *av;
     register I32 i;
@@ -258,7 +285,7 @@ register SV **strp;
 	New(4,ary,size,SV*);
 	AvALLOC(av) = ary;
 	SvPVX(av) = (char*)ary;
-	AvFILL(av) = size - 1;
+	AvFILLp(av) = size - 1;
 	AvMAX(av) = size - 1;
 	for (i = 0; i < size; i++) {
 	    assert (*strp);
@@ -271,9 +298,7 @@ register SV **strp;
 }
 
 AV *
-av_fake(size,strp)
-register I32 size;
-register SV **strp;
+Perl_av_fake(pTHX_ register I32 size, register SV **strp)
 {
     register AV *av;
     register SV** ary;
@@ -285,7 +310,7 @@ register SV **strp;
     Copy(strp,ary,size,SV*);
     AvFLAGS(av) = AVf_REIFY;
     SvPVX(av) = (char*)ary;
-    AvFILL(av) = size - 1;
+    AvFILLp(av) = size - 1;
     AvMAX(av) = size - 1;
     while (size--) {
 	assert (*strp);
@@ -296,54 +321,68 @@ register SV **strp;
 }
 
 void
-av_clear(av)
-register AV *av;
+Perl_av_clear(pTHX_ register AV *av)
 {
     register I32 key;
     SV** ary;
 
 #ifdef DEBUGGING
-    if (SvREFCNT(av) <= 0) {
-	warn("Attempt to clear deleted array");
+    if (SvREFCNT(av) <= 0 && ckWARN_d(WARN_DEBUGGING)) {
+	Perl_warner(aTHX_ WARN_DEBUGGING, "Attempt to clear deleted array");
     }
 #endif
-    if (!av || AvMAX(av) < 0)
+    if (!av)
 	return;
     /*SUPPRESS 560*/
 
+    if (SvREADONLY(av))
+	Perl_croak(aTHX_ PL_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 = AvFILL(av) + 1;
+	key = AvFILLp(av) + 1;
 	while (key) {
 	    SvREFCNT_dec(ary[--key]);
-	    ary[key] = &sv_undef;
+	    ary[key] = &PL_sv_undef;
 	}
     }
     if (key = AvARRAY(av) - AvALLOC(av)) {
 	AvMAX(av) += key;
 	SvPVX(av) = (char*)AvALLOC(av);
     }
-    AvFILL(av) = -1;
+    AvFILLp(av) = -1;
+
 }
 
 void
-av_undef(av)
-register AV *av;
+Perl_av_undef(pTHX_ register AV *av)
 {
     register I32 key;
 
     if (!av)
 	return;
     /*SUPPRESS 560*/
+
+    /* Give any tie a chance to cleanup first */
+    if (SvTIED_mg((SV*)av, 'P')) 
+	av_fill(av, -1);   /* mg_clear() ? */
+
     if (AvREAL(av)) {
-	key = AvFILL(av) + 1;
+	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;
@@ -351,44 +390,93 @@ register AV *av;
 }
 
 void
-av_push(av,val)
-register AV *av;
-SV *val;
-{
+Perl_av_push(pTHX_ register AV *av, SV *val)
+{             
+    MAGIC *mg;
     if (!av)
 	return;
-    av_store(av,AvFILL(av)+1,val);
+    if (SvREADONLY(av))
+	Perl_croak(aTHX_ PL_no_modify);
+
+    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;
+	call_method("PUSH", G_SCALAR|G_DISCARD);
+	LEAVE;
+	POPSTACK;
+	return;
+    }
+    av_store(av,AvFILLp(av)+1,val);
 }
 
 SV *
-av_pop(av)
-register AV *av;
+Perl_av_pop(pTHX_ register AV *av)
 {
     SV *retval;
+    MAGIC* mg;
 
     if (!av || AvFILL(av) < 0)
-	return &sv_undef;
+	return &PL_sv_undef;
     if (SvREADONLY(av))
-	croak(no_modify);
-    retval = AvARRAY(av)[AvFILL(av)];
-    AvARRAY(av)[AvFILL(av)--] = &sv_undef;
+	Perl_croak(aTHX_ PL_no_modify);
+    if (mg = SvTIED_mg((SV*)av, 'P')) {
+	dSP;    
+	PUSHSTACKi(PERLSI_MAGIC);
+	PUSHMARK(SP);
+	XPUSHs(SvTIED_obj((SV*)av, mg));
+	PUTBACK;
+	ENTER;
+	if (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_unshift(av,num)
-register AV *av;
-register I32 num;
+Perl_av_unshift(pTHX_ register AV *av, register I32 num)
 {
     register I32 i;
-    register SV **sstr,**dstr;
+    register SV **ary;
+    MAGIC* mg;
 
     if (!av || num <= 0)
 	return;
     if (SvREADONLY(av))
-	croak(no_modify);
+	Perl_croak(aTHX_ PL_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;
+	call_method("UNSHIFT", G_SCALAR|G_DISCARD);
+	LEAVE;
+	POPSTACK;
+	return;
+    }
+
     if (!AvREAL(av) && AvREIFY(av))
 	av_reify(av);
     i = AvARRAY(av) - AvALLOC(av);
@@ -398,84 +486,277 @@ register I32 num;
 	num -= i;
     
 	AvMAX(av) += i;
-	AvFILL(av) += i;
+	AvFILLp(av) += i;
 	SvPVX(av) = (char*)(AvARRAY(av) - i);
     }
     if (num) {
-	av_extend(av,AvFILL(av)+num);
-	AvFILL(av) += num;
-	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 */
-	}
-	while (num)
-	    AvARRAY(av)[--num] = &sv_undef;
+	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;
+Perl_av_shift(pTHX_ register AV *av)
 {
     SV *retval;
+    MAGIC* mg;
 
     if (!av || AvFILL(av) < 0)
-	return &sv_undef;
+	return &PL_sv_undef;
     if (SvREADONLY(av))
-	croak(no_modify);
+	Perl_croak(aTHX_ PL_no_modify);
+    if (mg = SvTIED_mg((SV*)av, 'P')) {
+	dSP;
+	PUSHSTACKi(PERLSI_MAGIC);
+	PUSHMARK(SP);
+	XPUSHs(SvTIED_obj((SV*)av, mg));
+	PUTBACK;
+	ENTER;
+	if (call_method("SHIFT", G_SCALAR)) {
+	    retval = newSVsv(*PL_stack_sp--);            
+	} else {    
+	    retval = &PL_sv_undef;
+	}     
+	LEAVE;
+	POPSTACK;
+	return retval;
+    }
     retval = *AvARRAY(av);
     if (AvREAL(av))
-	*AvARRAY(av) = &sv_undef;
+	*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;
+Perl_av_len(pTHX_ register AV *av)
 {
     return AvFILL(av);
 }
 
 void
-av_fill(av, fill)
-register AV *av;
-I32 fill;
+Perl_av_fill(pTHX_ register AV *av, I32 fill)
 {
+    MAGIC *mg;
     if (!av)
-	croak("panic: null array");
+	Perl_croak(aTHX_ "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;
+	call_method("STORESIZE", G_SCALAR|G_DISCARD);
+	POPSTACK;
+	FREETMPS;
+	LEAVE;
+	return;
+    }
     if (fill <= AvMAX(av)) {
-	I32 key = AvFILL(av);
+	I32 key = AvFILLp(av);
 	SV** ary = AvARRAY(av);
 
 	if (AvREAL(av)) {
 	    while (key > fill) {
 		SvREFCNT_dec(ary[key]);
-		ary[key--] = &sv_undef;
+		ary[key--] = &PL_sv_undef;
 	    }
 	}
 	else {
 	    while (key < fill)
-		ary[++key] = &sv_undef;
+		ary[++key] = &PL_sv_undef;
 	}
 	    
-	AvFILL(av) = fill;
+	AvFILLp(av) = fill;
+	if (SvSMAGICAL(av))
+	    mg_set((SV*)av);
+    }
+    else
+	(void)av_store(av,fill,&PL_sv_undef);
+}
+
+SV *
+Perl_av_delete(pTHX_ AV *av, I32 key, I32 flags)
+{
+    SV *sv;
+
+    if (!av)
+	return Nullsv;
+    if (SvREADONLY(av))
+	Perl_croak(aTHX_ PL_no_modify);
+    if (key < 0) {
+	key += AvFILL(av) + 1;
+	if (key < 0)
+	    return Nullsv;
+    }
+    if (SvRMAGICAL(av)) {
+	SV **svp;
+	if ((mg_find((SV*)av,'P') || mg_find((SV*)av,'D'))
+	    && (svp = av_fetch(av, key, TRUE)))
+	{
+	    sv = *svp;
+	    mg_clear(sv);
+	    if (mg_find(sv, 'p')) {
+		sv_unmagic(sv, 'p');		/* No longer an element */
+		return sv;
+	    }
+	    return Nullsv;			/* element cannot be deleted */
+	}
+    }
+    if (key > AvFILLp(av))
+	return Nullsv;
+    else {
+	sv = AvARRAY(av)[key];
+	if (key == AvFILLp(av)) {
+	    do {
+		AvFILLp(av)--;
+	    } while (--key >= 0 && AvARRAY(av)[key] == &PL_sv_undef);
+	}
+	else
+	    AvARRAY(av)[key] = &PL_sv_undef;
 	if (SvSMAGICAL(av))
 	    mg_set((SV*)av);
     }
+    if (flags & G_DISCARD) {
+	SvREFCNT_dec(sv);
+	sv = Nullsv;
+    }
+    return sv;
+}
+
+/*
+ * This relies on the fact that uninitialized array elements
+ * are set to &PL_sv_undef.
+ */
+
+bool
+Perl_av_exists(pTHX_ AV *av, I32 key)
+{
+    if (!av)
+	return FALSE;
+    if (key < 0) {
+	key += AvFILL(av) + 1;
+	if (key < 0)
+	    return FALSE;
+    }
+    if (SvRMAGICAL(av)) {
+	if (mg_find((SV*)av,'P') || mg_find((SV*)av,'D')) {
+	    SV *sv = sv_newmortal();
+	    mg_copy((SV*)av, sv, 0, key);
+	    magic_existspack(sv, mg_find(sv, 'p'));
+	    return SvTRUE(sv);
+	}
+    }
+    if (key <= AvFILLp(av) && AvARRAY(av)[key] != &PL_sv_undef
+	&& AvARRAY(av)[key])
+    {
+	return TRUE;
+    }
     else
-	(void)av_store(av,fill,&sv_undef);
+	return FALSE;
+}
+
+/* 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
+S_avhv_index_sv(pTHX_ SV* sv)
+{
+    I32 index = SvIV(sv);
+    if (index < 1)
+	Perl_croak(aTHX_ "Bad index while coercing array into hash");
+    return index;    
+}
+
+HV*
+Perl_avhv_keys(pTHX_ 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;
+	}
+    }
+    Perl_croak(aTHX_ "Can't coerce array into hash");
+    return Nullhv;
+}
+
+SV**
+Perl_avhv_fetch_ent(pTHX_ AV *av, SV *keysv, I32 lval, U32 hash)
+{
+    SV **indsvp;
+    HV *keys = avhv_keys(av);
+    HE *he;
+    STRLEN n_a;
+   
+    he = hv_fetch_ent(keys, keysv, FALSE, hash);
+    if (!he)
+        Perl_croak(aTHX_ "No such pseudo-hash field \"%s\"", SvPV(keysv,n_a));
+    return av_fetch(av, avhv_index_sv(HeVAL(he)), lval);
+}
+
+SV *
+Perl_avhv_delete_ent(pTHX_ AV *av, SV *keysv, I32 flags, U32 hash)
+{
+    HV *keys = avhv_keys(av);
+    HE *he;
+	
+    he = hv_fetch_ent(keys, keysv, FALSE, hash);
+    if (!he || !SvOK(HeVAL(he)))
+	return Nullsv;
+
+    return av_delete(av, avhv_index_sv(HeVAL(he)), flags);
+}
+
+/* Check for the existence of an element named by a given key.
+ *
+ */
+bool
+Perl_avhv_exists_ent(pTHX_ AV *av, SV *keysv, U32 hash)
+{
+    HV *keys = avhv_keys(av);
+    HE *he;
+	
+    he = hv_fetch_ent(keys, keysv, FALSE, hash);
+    if (!he || !SvOK(HeVAL(he)))
+	return FALSE;
+
+    return av_exists(av, avhv_index_sv(HeVAL(he)));
+}
+
+HE *
+Perl_avhv_iternext(pTHX_ AV *av)
+{
+    HV *keys = avhv_keys(av);
+    return hv_iternext(keys);
+}
+
+SV *
+Perl_avhv_iterval(pTHX_ AV *av, register HE *entry)
+{
+    SV *sv = hv_iterval(avhv_keys(av), entry);
+    return *av_fetch(av, avhv_index_sv(sv), TRUE);
 }