X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/e788e7d35b1f8979a002a1e994535be7aae30018..1d76a5c36fe33e7755afd0f03faf19826beda303:/av.c

diff --git a/av.c b/av.c
index 5aac5b1..819887e 100644
--- a/av.c
+++ b/av.c
@@ -1,6 +1,6 @@
 /*    av.c
  *
- *    Copyright (c) 1991-1997, Larry Wall
+ *    Copyright (c) 1991-2000, 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.
@@ -13,10 +13,11 @@
  */
 
 #include "EXTERN.h"
+#define PERL_IN_AV_C
 #include "perl.h"
 
 void
-av_reify(AV *av)
+Perl_av_reify(pTHX_ AV *av)
 {
     I32 key;
     SV* sv;
@@ -24,42 +25,52 @@ av_reify(AV *av)
     if (AvREAL(av))
 	return;
 #ifdef DEBUGGING
-    if (SvRMAGICAL(av) && mg_find((SV*)av,'P'))
-	warn("av_reify called on tied array");
+    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 > AvFILLp(av) + 1)
-	AvARRAY(av)[--key] = &sv_undef;
+	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);
 }
 
+/*
+=for apidoc av_extend
+
+Pre-extend an array.  The C<key> is the index to which the array should be
+extended.
+
+=cut
+*/
+
 void
-av_extend(AV *av, I32 key)
+Perl_av_extend(pTHX_ AV *av, I32 key)
 {
     dTHR;			/* only necessary if we have to extend stack */
     MAGIC *mg;
-    if (SvRMAGICAL(av) && (mg = mg_find((SV*)av,'P'))) {
+    if ((mg = SvTIED_mg((SV*)av, 'P'))) {
 	dSP;
 	ENTER;
 	SAVETMPS;
 	PUSHSTACKi(PERLSI_MAGIC);
 	PUSHMARK(SP);
 	EXTEND(SP,2);
-	PUSHs(mg->mg_obj);
+	PUSHs(SvTIED_obj((SV*)av, mg));
 	PUSHs(sv_2mortal(newSViv(key+1)));
         PUTBACK;
-	perl_call_method("EXTEND", G_SCALAR|G_DISCARD);
+	call_method("EXTEND", G_SCALAR|G_DISCARD);
 	POPSTACK;
 	FREETMPS;
 	LEAVE;
@@ -78,7 +89,7 @@ av_extend(AV *av, I32 key)
 	    SvPVX(av) = (char*)AvALLOC(av);
 	    if (AvREAL(av)) {
 		while (tmp)
-		    ary[--tmp] = &sv_undef;
+		    ary[--tmp] = &PL_sv_undef;
 	    }
 	    
 	    if (key > AvMAX(av) - 10) {
@@ -89,10 +100,11 @@ av_extend(AV *av, I32 key)
 	else {
 	    if (AvALLOC(av)) {
 #ifndef STRANGE_MALLOC
-		U32 bytes;
+		MEM_SIZE bytes;
+		IV itmp;
 #endif
 
-#ifdef MYMALLOC
+#if defined(MYMALLOC) && !defined(LEAKTEST)
 		newmax = malloced_size((void*)AvALLOC(av))/sizeof(SV*) - 1;
 
 		if (key <= newmax) 
@@ -105,13 +117,14 @@ av_extend(AV *av, I32 key)
 #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)
@@ -123,10 +136,10 @@ av_extend(AV *av, I32 key)
 	      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 {
@@ -134,11 +147,11 @@ av_extend(AV *av, I32 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);
@@ -147,8 +160,21 @@ av_extend(AV *av, I32 key)
     }
 }
 
+/*
+=for apidoc av_fetch
+
+Returns the SV at the specified index in the array.  The C<key> is the
+index.  If C<lval> is set then the fetch will be part of a store.  Check
+that the return value is non-null before dereferencing it to a C<SV*>.
+
+See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for
+more information on how to use this function on tied arrays. 
+
+=cut
+*/
+
 SV**
-av_fetch(register AV *av, I32 key, I32 lval)
+Perl_av_fetch(pTHX_ register AV *av, I32 key, I32 lval)
 {
     SV *sv;
 
@@ -162,25 +188,22 @@ av_fetch(register AV *av, I32 key, I32 lval)
     }
 
     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);
-	    av_fetch_sv = sv;
-	    return &av_fetch_sv;
+	    PL_av_fetch_sv = sv;
+	    return &PL_av_fetch_sv;
 	}
     }
 
     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);
@@ -191,23 +214,38 @@ av_fetch(register AV *av, I32 key, 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];
 }
 
+/*
+=for apidoc av_store
+
+Stores an SV in an array.  The array index is specified as C<key>.  The
+return value will be NULL if the operation failed or if the value did not
+need to be actually stored within the array (as in the case of tied
+arrays). Otherwise it can be dereferenced to get the original C<SV*>.  Note
+that the caller is responsible for suitably incrementing the reference
+count of C<val> before the call, and decrementing it if the function
+returned NULL.
+
+See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for
+more information on how to use this function on tied arrays.
+
+=cut
+*/
+
 SV**
-av_store(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;
@@ -216,11 +254,11 @@ av_store(register AV *av, I32 key, SV *val)
     }
 
     if (SvREADONLY(av) && key >= AvFILL(av))
-	croak(no_modify);
+	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;
@@ -235,10 +273,10 @@ av_store(register AV *av, I32 key, SV *val)
     if (AvFILLp(av) < key) {
 	if (!AvREAL(av)) {
 	    dTHR;
-	    if (av == curstack && key > stack_sp - stack_base)
-		stack_sp = stack_base + key;	/* XPUSH in disguise */
+	    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)] = &sv_undef;
+		ary[++AvFILLp(av)] = &PL_sv_undef;
 	    while (AvFILLp(av) < key);
 	}
 	AvFILLp(av) = key;
@@ -247,7 +285,7 @@ av_store(register AV *av, I32 key, SV *val)
 	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);
 	}
@@ -256,8 +294,16 @@ av_store(register AV *av, I32 key, SV *val)
     return &ary[key];
 }
 
+/*
+=for apidoc newAV
+
+Creates a new AV.  The reference count is set to 1.
+
+=cut
+*/
+
 AV *
-newAV(void)
+Perl_newAV(pTHX)
 {
     register AV *av;
 
@@ -270,8 +316,18 @@ newAV(void)
     return av;
 }
 
+/*
+=for apidoc av_make
+
+Creates a new AV and populates it with a list of SVs.  The SVs are copied
+into the array, so they may be freed after the call to av_make.  The new AV
+will have a reference count of 1.
+
+=cut
+*/
+
 AV *
-av_make(register I32 size, register SV **strp)
+Perl_av_make(pTHX_ register I32 size, register SV **strp)
 {
     register AV *av;
     register I32 i;
@@ -297,7 +353,7 @@ av_make(register I32 size, register SV **strp)
 }
 
 AV *
-av_fake(register I32 size, register SV **strp)
+Perl_av_fake(pTHX_ register I32 size, register SV **strp)
 {
     register AV *av;
     register SV** ary;
@@ -319,15 +375,24 @@ av_fake(register I32 size, register SV **strp)
     return av;
 }
 
+/*
+=for apidoc av_clear
+
+Clears an array, making it empty.  Does not free the memory used by the
+array itself.
+
+=cut
+*/
+
 void
-av_clear(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)
@@ -335,7 +400,7 @@ av_clear(register AV *av)
     /*SUPPRESS 560*/
 
     if (SvREADONLY(av))
-	croak(no_modify);
+	Perl_croak(aTHX_ PL_no_modify);
 
     /* Give any tie a chance to cleanup first */
     if (SvRMAGICAL(av))
@@ -349,10 +414,10 @@ av_clear(register AV *av)
 	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)) {
+    if ((key = AvARRAY(av) - AvALLOC(av))) {
 	AvMAX(av) += key;
 	SvPVX(av) = (char*)AvALLOC(av);
     }
@@ -360,8 +425,16 @@ av_clear(register AV *av)
 
 }
 
+/*
+=for apidoc av_undef
+
+Undefines the array.  Frees the memory used by the array itself.
+
+=cut
+*/
+
 void
-av_undef(register AV *av)
+Perl_av_undef(pTHX_ register AV *av)
 {
     register I32 key;
 
@@ -370,7 +443,7 @@ av_undef(register AV *av)
     /*SUPPRESS 560*/
 
     /* Give any tie a chance to cleanup first */
-    if (SvRMAGICAL(av) && mg_find((SV*)av,'P')) 
+    if (SvTIED_mg((SV*)av, 'P')) 
 	av_fill(av, -1);   /* mg_clear() ? */
 
     if (AvREAL(av)) {
@@ -388,25 +461,34 @@ av_undef(register AV *av)
     }
 }
 
+/*
+=for apidoc av_push
+
+Pushes an SV onto the end of the array.  The array will grow automatically
+to accommodate the addition.
+
+=cut
+*/
+
 void
-av_push(register AV *av, SV *val)
+Perl_av_push(pTHX_ register AV *av, SV *val)
 {             
     MAGIC *mg;
     if (!av)
 	return;
     if (SvREADONLY(av))
-	croak(no_modify);
+	Perl_croak(aTHX_ PL_no_modify);
 
-    if (SvRMAGICAL(av) && (mg = mg_find((SV*)av,'P'))) {
+    if ((mg = SvTIED_mg((SV*)av, 'P'))) {
 	dSP;
 	PUSHSTACKi(PERLSI_MAGIC);
 	PUSHMARK(SP);
 	EXTEND(SP,2);
-	PUSHs(mg->mg_obj);
+	PUSHs(SvTIED_obj((SV*)av, mg));
 	PUSHs(val);
 	PUTBACK;
 	ENTER;
-	perl_call_method("PUSH", G_SCALAR|G_DISCARD);
+	call_method("PUSH", G_SCALAR|G_DISCARD);
 	LEAVE;
 	POPSTACK;
 	return;
@@ -414,41 +496,60 @@ av_push(register AV *av, SV *val)
     av_store(av,AvFILLp(av)+1,val);
 }
 
+/*
+=for apidoc av_pop
+
+Pops an SV off the end of the array.  Returns C<&PL_sv_undef> if the array
+is empty.
+
+=cut
+*/
+
 SV *
-av_pop(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);
-    if (SvRMAGICAL(av) && (mg = mg_find((SV*)av,'P'))) {
+	Perl_croak(aTHX_ PL_no_modify);
+    if ((mg = SvTIED_mg((SV*)av, 'P'))) {
 	dSP;    
 	PUSHSTACKi(PERLSI_MAGIC);
 	PUSHMARK(SP);
-	XPUSHs(mg->mg_obj);
+	XPUSHs(SvTIED_obj((SV*)av, mg));
 	PUTBACK;
 	ENTER;
-	if (perl_call_method("POP", G_SCALAR)) {
-	    retval = newSVsv(*stack_sp--);    
+	if (call_method("POP", G_SCALAR)) {
+	    retval = newSVsv(*PL_stack_sp--);    
 	} else {    
-	    retval = &sv_undef;
+	    retval = &PL_sv_undef;
 	}
 	LEAVE;
 	POPSTACK;
 	return retval;
     }
     retval = AvARRAY(av)[AvFILLp(av)];
-    AvARRAY(av)[AvFILLp(av)--] = &sv_undef;
+    AvARRAY(av)[AvFILLp(av)--] = &PL_sv_undef;
     if (SvSMAGICAL(av))
 	mg_set((SV*)av);
     return retval;
 }
 
+/*
+=for apidoc av_unshift
+
+Unshift the given number of C<undef> values onto the beginning of the
+array.  The array will grow automatically to accommodate the addition.  You
+must then use C<av_store> to assign values to these new elements.
+
+=cut
+*/
+
 void
-av_unshift(register AV *av, register I32 num)
+Perl_av_unshift(pTHX_ register AV *av, register I32 num)
 {
     register I32 i;
     register SV **ary;
@@ -457,20 +558,20 @@ av_unshift(register AV *av, register I32 num)
     if (!av || num <= 0)
 	return;
     if (SvREADONLY(av))
-	croak(no_modify);
+	Perl_croak(aTHX_ PL_no_modify);
 
-    if (SvRMAGICAL(av) && (mg = mg_find((SV*)av,'P'))) {
+    if ((mg = SvTIED_mg((SV*)av, 'P'))) {
 	dSP;
 	PUSHSTACKi(PERLSI_MAGIC);
 	PUSHMARK(SP);
 	EXTEND(SP,1+num);
-	PUSHs(mg->mg_obj);
+	PUSHs(SvTIED_obj((SV*)av, mg));
 	while (num-- > 0) {
-	    PUSHs(&sv_undef);
+	    PUSHs(&PL_sv_undef);
 	}
 	PUTBACK;
 	ENTER;
-	perl_call_method("UNSHIFT", G_SCALAR|G_DISCARD);
+	call_method("UNSHIFT", G_SCALAR|G_DISCARD);
 	LEAVE;
 	POPSTACK;
 	return;
@@ -495,32 +596,40 @@ av_unshift(register AV *av, register I32 num)
 	ary = AvARRAY(av);
 	Move(ary, ary + num, i + 1, SV*);
 	do {
-	    ary[--num] = &sv_undef;
+	    ary[--num] = &PL_sv_undef;
 	} while (num);
     }
 }
 
+/*
+=for apidoc av_shift
+
+Shifts an SV off the beginning of the array.
+
+=cut
+*/
+
 SV *
-av_shift(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);
-    if (SvRMAGICAL(av) && (mg = mg_find((SV*)av,'P'))) {
+	Perl_croak(aTHX_ PL_no_modify);
+    if ((mg = SvTIED_mg((SV*)av, 'P'))) {
 	dSP;
 	PUSHSTACKi(PERLSI_MAGIC);
 	PUSHMARK(SP);
-	XPUSHs(mg->mg_obj);
+	XPUSHs(SvTIED_obj((SV*)av, mg));
 	PUTBACK;
 	ENTER;
-	if (perl_call_method("SHIFT", G_SCALAR)) {
-	    retval = newSVsv(*stack_sp--);            
+	if (call_method("SHIFT", G_SCALAR)) {
+	    retval = newSVsv(*PL_stack_sp--);            
 	} else {    
-	    retval = &sv_undef;
+	    retval = &PL_sv_undef;
 	}     
 	LEAVE;
 	POPSTACK;
@@ -528,7 +637,7 @@ av_shift(register AV *av)
     }
     retval = *AvARRAY(av);
     if (AvREAL(av))
-	*AvARRAY(av) = &sv_undef;
+	*AvARRAY(av) = &PL_sv_undef;
     SvPVX(av) = (char*)(AvARRAY(av) + 1);
     AvMAX(av)--;
     AvFILLp(av)--;
@@ -537,31 +646,40 @@ av_shift(register AV *av)
     return retval;
 }
 
+/*
+=for apidoc av_len
+
+Returns the highest index in the array.  Returns -1 if the array is
+empty.
+
+=cut
+*/
+
 I32
-av_len(register AV *av)
+Perl_av_len(pTHX_ register AV *av)
 {
     return AvFILL(av);
 }
 
 void
-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 (SvRMAGICAL(av) && (mg = mg_find((SV*)av,'P'))) {
+    if ((mg = SvTIED_mg((SV*)av, 'P'))) {
 	dSP;            
 	ENTER;
 	SAVETMPS;
 	PUSHSTACKi(PERLSI_MAGIC);
 	PUSHMARK(SP);
 	EXTEND(SP,2);
-	PUSHs(mg->mg_obj);
+	PUSHs(SvTIED_obj((SV*)av, mg));
 	PUSHs(sv_2mortal(newSViv(fill+1)));
 	PUTBACK;
-	perl_call_method("STORESIZE", G_SCALAR|G_DISCARD);
+	call_method("STORESIZE", G_SCALAR|G_DISCARD);
 	POPSTACK;
 	FREETMPS;
 	LEAVE;
@@ -574,12 +692,12 @@ av_fill(register AV *av, I32 fill)
 	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;
 	}
 	    
 	AvFILLp(av) = fill;
@@ -587,9 +705,89 @@ av_fill(register AV *av, I32 fill)
 	    mg_set((SV*)av);
     }
     else
-	(void)av_store(av,fill,&sv_undef);
+	(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
+	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
@@ -597,16 +795,30 @@ av_fill(register AV *av, I32 fill)
  */
 
 STATIC I32
-avhv_index_sv(SV* sv)
+S_avhv_index_sv(pTHX_ SV* sv)
 {
     I32 index = SvIV(sv);
     if (index < 1)
-	croak("Bad index while coercing array into hash");
+	Perl_croak(aTHX_ "Bad index while coercing array into hash");
     return index;    
 }
 
+STATIC I32
+S_avhv_index(pTHX_ AV *av, SV *keysv, U32 hash)
+{
+    HV *keys;
+    HE *he;
+    STRLEN n_a;
+
+    keys = avhv_keys(av);
+    he = hv_fetch_ent(keys, keysv, FALSE, hash);
+    if (!he)
+        Perl_croak(aTHX_ "No such pseudo-hash field \"%s\"", SvPV(keysv,n_a));
+    return avhv_index_sv(HeVAL(he));
+}
+
 HV*
-avhv_keys(AV *av)
+Perl_avhv_keys(pTHX_ AV *av)
 {
     SV **keysp = av_fetch(av, 0, FALSE);
     if (keysp) {
@@ -619,39 +831,60 @@ avhv_keys(AV *av)
 		return (HV*)sv;
 	}
     }
-    croak("Can't coerce array into hash");
+    Perl_croak(aTHX_ "Can't coerce array into hash");
     return Nullhv;
 }
 
 SV**
-avhv_fetch_ent(AV *av, SV *keysv, I32 lval, U32 hash)
+Perl_avhv_store_ent(pTHX_ AV *av, SV *keysv, SV *val, U32 hash)
+{
+    return av_store(av, avhv_index(av, keysv, hash), val);
+}
+
+SV**
+Perl_avhv_fetch_ent(pTHX_ AV *av, SV *keysv, I32 lval, U32 hash)
+{
+    return av_fetch(av, avhv_index(av, keysv, hash), lval);
+}
+
+SV *
+Perl_avhv_delete_ent(pTHX_ AV *av, SV *keysv, I32 flags, 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);
+    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
-avhv_exists_ent(AV *av, SV *keysv, U32 hash)
+Perl_avhv_exists_ent(pTHX_ AV *av, SV *keysv, U32 hash)
 {
     HV *keys = avhv_keys(av);
-    return hv_exists_ent(keys, keysv, hash);
+    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 *
-avhv_iternext(AV *av)
+Perl_avhv_iternext(pTHX_ AV *av)
 {
     HV *keys = avhv_keys(av);
     return hv_iternext(keys);
 }
 
 SV *
-avhv_iterval(AV *av, register HE *entry)
+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);