3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
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.
12 * '...for the Entwives desired order, and plenty, and peace (by which they
13 * meant that things should remain where they had set them).' --Treebeard
15 * [p.476 of _The Lord of the Rings_, III/iv: "Treebeard"]
19 =head1 Array Manipulation Functions
27 Perl_av_reify(pTHX_ AV *av)
32 PERL_ARGS_ASSERT_AV_REIFY;
33 assert(SvTYPE(av) == SVt_PVAV);
38 if (SvTIED_mg((const SV *)av, PERL_MAGIC_tied))
39 Perl_ck_warner_d(aTHX_ packWARN(WARN_DEBUGGING), "av_reify called on tied array");
42 while (key > AvFILLp(av) + 1)
43 AvARRAY(av)[--key] = &PL_sv_undef;
45 SV * const sv = AvARRAY(av)[--key];
47 if (sv != &PL_sv_undef)
48 SvREFCNT_inc_simple_void_NN(sv);
50 key = AvARRAY(av) - AvALLOC(av);
52 AvALLOC(av)[--key] = &PL_sv_undef;
60 Pre-extend an array. The C<key> is the index to which the array should be
67 Perl_av_extend(pTHX_ AV *av, I32 key)
72 PERL_ARGS_ASSERT_AV_EXTEND;
73 assert(SvTYPE(av) == SVt_PVAV);
75 mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied);
77 SV *arg1 = sv_newmortal();
78 sv_setiv(arg1, (IV)(key + 1));
79 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "EXTEND", G_DISCARD, 1,
83 if (key > AvMAX(av)) {
88 if (AvALLOC(av) != AvARRAY(av)) {
89 ary = AvALLOC(av) + AvFILLp(av) + 1;
90 tmp = AvARRAY(av) - AvALLOC(av);
91 Move(AvARRAY(av), AvALLOC(av), AvFILLp(av)+1, SV*);
93 AvARRAY(av) = AvALLOC(av);
96 ary[--tmp] = &PL_sv_undef;
98 if (key > AvMAX(av) - 10) {
99 newmax = key + AvMAX(av);
104 #ifdef PERL_MALLOC_WRAP
105 static const char oom_array_extend[] =
106 "Out of memory during array extend"; /* Duplicated in pp_hot.c */
110 #if !defined(STRANGE_MALLOC) && !defined(MYMALLOC)
115 #ifdef Perl_safesysmalloc_size
116 /* Whilst it would be quite possible to move this logic around
117 (as I did in the SV code), so as to set AvMAX(av) early,
118 based on calling Perl_safesysmalloc_size() immediately after
119 allocation, I'm not convinced that it is a great idea here.
120 In an array we have to loop round setting everything to
121 &PL_sv_undef, which means writing to memory, potentially lots
122 of it, whereas for the SV buffer case we don't touch the
123 "bonus" memory. So there there is no cost in telling the
124 world about it, whereas here we have to do work before we can
125 tell the world about it, and that work involves writing to
126 memory that might never be read. So, I feel, better to keep
127 the current lazy system of only writing to it if our caller
128 has a need for more space. NWC */
129 newmax = Perl_safesysmalloc_size((void*)AvALLOC(av)) /
130 sizeof(const SV *) - 1;
135 newmax = key + AvMAX(av) / 5;
137 MEM_WRAP_CHECK_1(newmax+1, SV*, oom_array_extend);
138 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
139 Renew(AvALLOC(av),newmax+1, SV*);
141 bytes = (newmax + 1) * sizeof(const SV *);
142 #define MALLOC_OVERHEAD 16
143 itmp = MALLOC_OVERHEAD;
144 while ((MEM_SIZE)(itmp - MALLOC_OVERHEAD) < bytes)
146 itmp -= MALLOC_OVERHEAD;
147 itmp /= sizeof(const SV *);
148 assert(itmp > newmax);
150 assert(newmax >= AvMAX(av));
151 Newx(ary, newmax+1, SV*);
152 Copy(AvALLOC(av), ary, AvMAX(av)+1, SV*);
153 Safefree(AvALLOC(av));
156 #ifdef Perl_safesysmalloc_size
159 ary = AvALLOC(av) + AvMAX(av) + 1;
160 tmp = newmax - AvMAX(av);
161 if (av == PL_curstack) { /* Oops, grew stack (via av_store()?) */
162 PL_stack_sp = AvALLOC(av) + (PL_stack_sp - PL_stack_base);
163 PL_stack_base = AvALLOC(av);
164 PL_stack_max = PL_stack_base + newmax;
168 newmax = key < 3 ? 3 : key;
169 MEM_WRAP_CHECK_1(newmax+1, SV*, oom_array_extend);
170 Newx(AvALLOC(av), newmax+1, SV*);
171 ary = AvALLOC(av) + 1;
173 AvALLOC(av)[0] = &PL_sv_undef; /* For the stacks */
177 ary[--tmp] = &PL_sv_undef;
180 AvARRAY(av) = AvALLOC(av);
189 Returns the SV at the specified index in the array. The C<key> is the
190 index. If lval is true, you are guaranteed to get a real SV back (in case
191 it wasn't real before), which you can then modify. Check that the return
192 value is non-null before dereferencing it to a C<SV*>.
194 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for
195 more information on how to use this function on tied arrays.
197 The rough perl equivalent is C<$myarray[$idx]>.
203 Perl_av_fetch(pTHX_ register AV *av, I32 key, I32 lval)
207 PERL_ARGS_ASSERT_AV_FETCH;
208 assert(SvTYPE(av) == SVt_PVAV);
210 if (SvRMAGICAL(av)) {
211 const MAGIC * const tied_magic
212 = mg_find((const SV *)av, PERL_MAGIC_tied);
213 if (tied_magic || mg_find((const SV *)av, PERL_MAGIC_regdata)) {
216 I32 adjust_index = 1;
218 /* Handle negative array indices 20020222 MJD */
219 SV * const * const negative_indices_glob =
220 hv_fetch(SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(av),
222 NEGATIVE_INDICES_VAR, 16, 0);
224 if (negative_indices_glob && SvTRUE(GvSV(*negative_indices_glob)))
229 key += AvFILL(av) + 1;
236 sv_upgrade(sv, SVt_PVLV);
237 mg_copy(MUTABLE_SV(av), sv, 0, key);
238 if (!tied_magic) /* for regdata, force leavesub to make copies */
241 LvTARG(sv) = sv; /* fake (SV**) */
242 return &(LvTARG(sv));
247 key += AvFILL(av) + 1;
252 if (key > AvFILLp(av)) {
255 return av_store(av,key,newSV(0));
257 if (AvARRAY(av)[key] == &PL_sv_undef) {
260 return av_store(av,key,newSV(0));
264 && (!AvARRAY(av)[key] /* eg. @_ could have freed elts */
265 || SvIS_FREED(AvARRAY(av)[key]))) {
266 AvARRAY(av)[key] = &PL_sv_undef; /* 1/2 reify */
269 return &AvARRAY(av)[key];
275 Stores an SV in an array. The array index is specified as C<key>. The
276 return value will be NULL if the operation failed or if the value did not
277 need to be actually stored within the array (as in the case of tied
278 arrays). Otherwise, it can be dereferenced
279 to get the C<SV*> that was stored
282 Note that the caller is responsible for suitably incrementing the reference
283 count of C<val> before the call, and decrementing it if the function
286 Approximate Perl equivalent: C<$myarray[$key] = $val;>.
288 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for
289 more information on how to use this function on tied arrays.
295 Perl_av_store(pTHX_ register AV *av, I32 key, SV *val)
300 PERL_ARGS_ASSERT_AV_STORE;
301 assert(SvTYPE(av) == SVt_PVAV);
303 /* S_regclass relies on being able to pass in a NULL sv
304 (unicode_alternate may be NULL).
310 if (SvRMAGICAL(av)) {
311 const MAGIC * const tied_magic = mg_find((const SV *)av, PERL_MAGIC_tied);
313 /* Handle negative array indices 20020222 MJD */
315 bool adjust_index = 1;
316 SV * const * const negative_indices_glob =
317 hv_fetch(SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(av),
319 NEGATIVE_INDICES_VAR, 16, 0);
320 if (negative_indices_glob
321 && SvTRUE(GvSV(*negative_indices_glob)))
324 key += AvFILL(av) + 1;
329 if (val != &PL_sv_undef) {
330 mg_copy(MUTABLE_SV(av), val, 0, key);
338 key += AvFILL(av) + 1;
343 if (SvREADONLY(av) && key >= AvFILL(av))
344 Perl_croak_no_modify(aTHX);
346 if (!AvREAL(av) && AvREIFY(av))
351 if (AvFILLp(av) < key) {
353 if (av == PL_curstack && key > PL_stack_sp - PL_stack_base)
354 PL_stack_sp = PL_stack_base + key; /* XPUSH in disguise */
356 ary[++AvFILLp(av)] = &PL_sv_undef;
357 } while (AvFILLp(av) < key);
362 SvREFCNT_dec(ary[key]);
364 if (SvSMAGICAL(av)) {
365 const MAGIC *mg = SvMAGIC(av);
367 for (; mg; mg = mg->mg_moremagic) {
368 if (!isUPPER(mg->mg_type)) continue;
369 if (val != &PL_sv_undef) {
370 sv_magic(val, MUTABLE_SV(av), toLOWER(mg->mg_type), 0, key);
372 if (PL_delaymagic && mg->mg_type == PERL_MAGIC_isa) {
373 PL_delaymagic |= DM_ARRAY_ISA;
378 mg_set(MUTABLE_SV(av));
386 Creates a new AV and populates it with a list of SVs. The SVs are copied
387 into the array, so they may be freed after the call to av_make. The new AV
388 will have a reference count of 1.
390 Perl equivalent: C<my @new_array = ($scalar1, $scalar2, $scalar3...);>
396 Perl_av_make(pTHX_ register I32 size, register SV **strp)
398 register AV * const av = MUTABLE_AV(newSV_type(SVt_PVAV));
399 /* sv_upgrade does AvREAL_only() */
400 PERL_ARGS_ASSERT_AV_MAKE;
401 assert(SvTYPE(av) == SVt_PVAV);
403 if (size) { /* "defined" was returning undef for size==0 anyway. */
409 AvFILLp(av) = AvMAX(av) = size - 1;
410 for (i = 0; i < size; i++) {
413 /* Don't let sv_setsv swipe, since our source array might
414 have multiple references to the same temp scalar (e.g.
415 from a list slice) */
418 sv_setsv_flags(ary[i], *strp,
419 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
429 Clears an array, making it empty. Does not free the memory used by the
430 array itself. Perl equivalent: C<@myarray = ();>.
436 Perl_av_clear(pTHX_ register AV *av)
442 PERL_ARGS_ASSERT_AV_CLEAR;
443 assert(SvTYPE(av) == SVt_PVAV);
446 if (SvREFCNT(av) == 0) {
447 Perl_ck_warner_d(aTHX_ packWARN(WARN_DEBUGGING), "Attempt to clear deleted array");
452 Perl_croak_no_modify(aTHX);
454 /* Give any tie a chance to cleanup first */
455 if (SvRMAGICAL(av)) {
456 const MAGIC* const mg = SvMAGIC(av);
457 if (PL_delaymagic && mg && mg->mg_type == PERL_MAGIC_isa)
458 PL_delaymagic |= DM_ARRAY_ISA;
460 mg_clear(MUTABLE_SV(av));
466 if ((real = !!AvREAL(av))) {
467 SV** const ary = AvARRAY(av);
468 I32 index = AvFILLp(av) + 1;
470 SAVEFREESV(SvREFCNT_inc_simple_NN(av));
472 SV * const sv = ary[--index];
473 /* undef the slot before freeing the value, because a
474 * destructor might try to modify this array */
475 ary[index] = &PL_sv_undef;
479 extra = AvARRAY(av) - AvALLOC(av);
482 AvARRAY(av) = AvALLOC(av);
491 Undefines the array. Frees the memory used by the array itself.
497 Perl_av_undef(pTHX_ register AV *av)
501 PERL_ARGS_ASSERT_AV_UNDEF;
502 assert(SvTYPE(av) == SVt_PVAV);
504 /* Give any tie a chance to cleanup first */
505 if (SvTIED_mg((const SV *)av, PERL_MAGIC_tied))
508 if ((real = !!AvREAL(av))) {
509 register I32 key = AvFILLp(av) + 1;
511 SAVEFREESV(SvREFCNT_inc_simple_NN(av));
513 SvREFCNT_dec(AvARRAY(av)[--key]);
516 Safefree(AvALLOC(av));
519 AvMAX(av) = AvFILLp(av) = -1;
521 if(SvRMAGICAL(av)) mg_clear(MUTABLE_SV(av));
527 =for apidoc av_create_and_push
529 Push an SV onto the end of the array, creating the array if necessary.
530 A small internal helper function to remove a commonly duplicated idiom.
536 Perl_av_create_and_push(pTHX_ AV **const avp, SV *const val)
538 PERL_ARGS_ASSERT_AV_CREATE_AND_PUSH;
548 Pushes an SV onto the end of the array. The array will grow automatically
549 to accommodate the addition. This takes ownership of one reference count.
551 Perl equivalent: C<push @myarray, $elem;>.
557 Perl_av_push(pTHX_ register AV *av, SV *val)
562 PERL_ARGS_ASSERT_AV_PUSH;
563 assert(SvTYPE(av) == SVt_PVAV);
566 Perl_croak_no_modify(aTHX);
568 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
569 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "PUSH", G_DISCARD, 1,
573 av_store(av,AvFILLp(av)+1,val);
579 Pops an SV off the end of the array. Returns C<&PL_sv_undef> if the array
582 Perl equivalent: C<pop(@myarray);>
588 Perl_av_pop(pTHX_ register AV *av)
594 PERL_ARGS_ASSERT_AV_POP;
595 assert(SvTYPE(av) == SVt_PVAV);
598 Perl_croak_no_modify(aTHX);
599 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
600 retval = Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "POP", 0, 0);
602 retval = newSVsv(retval);
607 retval = AvARRAY(av)[AvFILLp(av)];
608 AvARRAY(av)[AvFILLp(av)--] = &PL_sv_undef;
610 mg_set(MUTABLE_SV(av));
616 =for apidoc av_create_and_unshift_one
618 Unshifts an SV onto the beginning of the array, creating the array if
620 A small internal helper function to remove a commonly duplicated idiom.
626 Perl_av_create_and_unshift_one(pTHX_ AV **const avp, SV *const val)
628 PERL_ARGS_ASSERT_AV_CREATE_AND_UNSHIFT_ONE;
633 return av_store(*avp, 0, val);
637 =for apidoc av_unshift
639 Unshift the given number of C<undef> values onto the beginning of the
640 array. The array will grow automatically to accommodate the addition. You
641 must then use C<av_store> to assign values to these new elements.
643 Perl equivalent: C<unshift @myarray, ( (undef) x $n );>
649 Perl_av_unshift(pTHX_ register AV *av, register I32 num)
655 PERL_ARGS_ASSERT_AV_UNSHIFT;
656 assert(SvTYPE(av) == SVt_PVAV);
659 Perl_croak_no_modify(aTHX);
661 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
662 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "UNSHIFT",
663 G_DISCARD | G_UNDEF_FILL, num);
669 if (!AvREAL(av) && AvREIFY(av))
671 i = AvARRAY(av) - AvALLOC(av);
679 AvARRAY(av) = AvARRAY(av) - i;
683 const I32 i = AvFILLp(av);
684 /* Create extra elements */
685 const I32 slide = i > 0 ? i : 0;
687 av_extend(av, i + num);
690 Move(ary, ary + num, i + 1, SV*);
692 ary[--num] = &PL_sv_undef;
694 /* Make extra elements into a buffer */
696 AvFILLp(av) -= slide;
697 AvARRAY(av) = AvARRAY(av) + slide;
704 Shifts an SV off the beginning of the
705 array. Returns C<&PL_sv_undef> if the
708 Perl equivalent: C<shift(@myarray);>
714 Perl_av_shift(pTHX_ register AV *av)
720 PERL_ARGS_ASSERT_AV_SHIFT;
721 assert(SvTYPE(av) == SVt_PVAV);
724 Perl_croak_no_modify(aTHX);
725 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
726 retval = Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "SHIFT", 0, 0);
728 retval = newSVsv(retval);
733 retval = *AvARRAY(av);
735 *AvARRAY(av) = &PL_sv_undef;
736 AvARRAY(av) = AvARRAY(av) + 1;
740 mg_set(MUTABLE_SV(av));
747 Returns the highest index in the array. The number of elements in the
748 array is C<av_len(av) + 1>. Returns -1 if the array is empty.
750 The Perl equivalent for this is C<$#myarray>.
756 Perl_av_len(pTHX_ AV *av)
758 PERL_ARGS_ASSERT_AV_LEN;
759 assert(SvTYPE(av) == SVt_PVAV);
767 Set the highest index in the array to the given number, equivalent to
768 Perl's C<$#array = $fill;>.
770 The number of elements in the an array will be C<fill + 1> after
771 av_fill() returns. If the array was previously shorter, then the
772 additional elements appended are set to C<PL_sv_undef>. If the array
773 was longer, then the excess elements are freed. C<av_fill(av, -1)> is
774 the same as C<av_clear(av)>.
779 Perl_av_fill(pTHX_ register AV *av, I32 fill)
784 PERL_ARGS_ASSERT_AV_FILL;
785 assert(SvTYPE(av) == SVt_PVAV);
789 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
790 SV *arg1 = sv_newmortal();
791 sv_setiv(arg1, (IV)(fill + 1));
792 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "STORESIZE", G_DISCARD,
796 if (fill <= AvMAX(av)) {
797 I32 key = AvFILLp(av);
798 SV** const ary = AvARRAY(av);
802 SvREFCNT_dec(ary[key]);
803 ary[key--] = &PL_sv_undef;
808 ary[++key] = &PL_sv_undef;
813 mg_set(MUTABLE_SV(av));
816 (void)av_store(av,fill,&PL_sv_undef);
820 =for apidoc av_delete
822 Deletes the element indexed by C<key> from the array, makes the element mortal,
823 and returns it. If C<flags> equals C<G_DISCARD>, the element is freed and null
824 is returned. Perl equivalent: C<my $elem = delete($myarray[$idx]);> for the
825 non-C<G_DISCARD> version and a void-context C<delete($myarray[$idx]);> for the
826 C<G_DISCARD> version.
831 Perl_av_delete(pTHX_ AV *av, I32 key, I32 flags)
836 PERL_ARGS_ASSERT_AV_DELETE;
837 assert(SvTYPE(av) == SVt_PVAV);
840 Perl_croak_no_modify(aTHX);
842 if (SvRMAGICAL(av)) {
843 const MAGIC * const tied_magic
844 = mg_find((const SV *)av, PERL_MAGIC_tied);
845 if ((tied_magic || mg_find((const SV *)av, PERL_MAGIC_regdata))) {
846 /* Handle negative array indices 20020222 MJD */
849 unsigned adjust_index = 1;
851 SV * const * const negative_indices_glob =
852 hv_fetch(SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(av),
854 NEGATIVE_INDICES_VAR, 16, 0);
855 if (negative_indices_glob
856 && SvTRUE(GvSV(*negative_indices_glob)))
860 key += AvFILL(av) + 1;
865 svp = av_fetch(av, key, TRUE);
869 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
870 sv_unmagic(sv, PERL_MAGIC_tiedelem); /* No longer an element */
879 key += AvFILL(av) + 1;
884 if (key > AvFILLp(av))
887 if (!AvREAL(av) && AvREIFY(av))
889 sv = AvARRAY(av)[key];
890 if (key == AvFILLp(av)) {
891 AvARRAY(av)[key] = &PL_sv_undef;
894 } while (--key >= 0 && AvARRAY(av)[key] == &PL_sv_undef);
897 AvARRAY(av)[key] = &PL_sv_undef;
899 mg_set(MUTABLE_SV(av));
901 if (flags & G_DISCARD) {
911 =for apidoc av_exists
913 Returns true if the element indexed by C<key> has been initialized.
915 This relies on the fact that uninitialized array elements are set to
918 Perl equivalent: C<exists($myarray[$key])>.
923 Perl_av_exists(pTHX_ AV *av, I32 key)
926 PERL_ARGS_ASSERT_AV_EXISTS;
927 assert(SvTYPE(av) == SVt_PVAV);
929 if (SvRMAGICAL(av)) {
930 const MAGIC * const tied_magic
931 = mg_find((const SV *)av, PERL_MAGIC_tied);
932 const MAGIC * const regdata_magic
933 = mg_find((const SV *)av, PERL_MAGIC_regdata);
934 if (tied_magic || regdata_magic) {
935 SV * const sv = sv_newmortal();
937 /* Handle negative array indices 20020222 MJD */
939 unsigned adjust_index = 1;
941 SV * const * const negative_indices_glob =
942 hv_fetch(SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(av),
944 NEGATIVE_INDICES_VAR, 16, 0);
945 if (negative_indices_glob
946 && SvTRUE(GvSV(*negative_indices_glob)))
950 key += AvFILL(av) + 1;
958 if(key >= 0 && regdata_magic) {
959 if (key <= AvFILL(av))
965 mg_copy(MUTABLE_SV(av), sv, 0, key);
966 mg = mg_find(sv, PERL_MAGIC_tiedelem);
968 magic_existspack(sv, mg);
969 return cBOOL(SvTRUE(sv));
976 key += AvFILL(av) + 1;
981 if (key <= AvFILLp(av) && AvARRAY(av)[key] != &PL_sv_undef
991 S_get_aux_mg(pTHX_ AV *av) {
995 PERL_ARGS_ASSERT_GET_AUX_MG;
996 assert(SvTYPE(av) == SVt_PVAV);
998 mg = mg_find((const SV *)av, PERL_MAGIC_arylen_p);
1001 mg = sv_magicext(MUTABLE_SV(av), 0, PERL_MAGIC_arylen_p,
1002 &PL_vtbl_arylen_p, 0, 0);
1004 /* sv_magicext won't set this for us because we pass in a NULL obj */
1005 mg->mg_flags |= MGf_REFCOUNTED;
1011 Perl_av_arylen_p(pTHX_ AV *av) {
1012 MAGIC *const mg = get_aux_mg(av);
1014 PERL_ARGS_ASSERT_AV_ARYLEN_P;
1015 assert(SvTYPE(av) == SVt_PVAV);
1017 return &(mg->mg_obj);
1021 Perl_av_iter_p(pTHX_ AV *av) {
1022 MAGIC *const mg = get_aux_mg(av);
1024 PERL_ARGS_ASSERT_AV_ITER_P;
1025 assert(SvTYPE(av) == SVt_PVAV);
1027 #if IVSIZE == I32SIZE
1028 return (IV *)&(mg->mg_len);
1032 mg->mg_len = IVSIZE;
1034 mg->mg_ptr = (char *) temp;
1036 return (IV *)mg->mg_ptr;
1042 * c-indentation-style: bsd
1044 * indent-tabs-mode: t
1047 * ex: set ts=8 sts=4 sw=4 noet: