=head2 Hash overhaul
Changes to the implementation of hashes in perl 5.18.0 will be one of the most
-visible changes to the behavior of existing code. For the most part, these
-changes will be visible as two distinct hash variables now providing their
-contents in a different order where it was previously identical. When
-encountering these changes, the key to cleaning up from them is to accept that
-B<hashes are unordered collections> and to act accordingly.
+visible changes to the behavior of existing code.
+
+By default, two distinct hash variables with identical keys and values will now
+provide their contents in a different order where it was previously identical.
+
+When encountering these changes, the key to cleaning up from them is to accept
+that B<hashes are unordered collections> and to act accordingly.
=head3 Hash randomization
perform equivalently to the old one for shorter strings and is faster for
hashing longer strings.
-=head3 PERL_HASH_SEED enviornment variable now takes a hex value
+=head3 PERL_HASH_SEED environment variable now takes a hex value
-PERL_HASH_SEED no longer accepts an integer as a parameter, instead the
-value is expected to be a binary string encoded in hex. This is to make
-the infrastructure support hash seeds of arbitrary lengths which might
+C<PERL_HASH_SEED> no longer accepts an integer as a parameter;
+instead the value is expected to be a binary value encoded in a hex
+string, such as "0xf5867c55039dc724". This is to make the
+infrastructure support hash seeds of arbitrary lengths, which might
exceed that of an integer. (SipHash uses a 16 byte seed).
=head3 PERL_PERTURB_KEYS environment variable added
-PERL_PERTURB_KEYS environment variable allows one to control the level of
+The C<PERL_PERTURB_KEYS> environment variable allows one to control the level of
randomization applied to C<keys> and friends.
-When PERL_PERTURB_KEYS is 0, perl will not randomize key order at all. The
+When C<PERL_PERTURB_KEYS> is 0, perl will not randomize the key order at all. The
chance that C<keys> changes due to an insert will be the same as in previous
perls, basically only when the bucket size is changed.
-When PERL_PERTURB_KEYS is 1, perl will randomize keys in a non repeatedable
+When C<PERL_PERTURB_KEYS> is 1, perl will randomize keys in a non-repeatable
way. The chance that C<keys> changes due to an insert will be very high. This
is the most secure and default mode.
-When PERL_PERTURB_KEYS is 2, perl will randomize keys in a repeatedable way.
-Repititive runs of the same program should produce the same output every time.
-The chance that keys changes due to an insert will be very high.
+When C<PERL_PERTURB_KEYS> is 2, perl will randomize keys in a repeatable way.
+Repeated runs of the same program should produce the same output every time.
-PERL_HASH_SEED implies a non-default PERL_PERTURB_KEYS setting. Setting
-PERL_HASH_SEED=0 (exactly one 0) implies PERL_PERTURB_KEYS=0 (hash key
-randomization disabled), settng PERL_HASH_SEED to any other value, implies
-PERL_PERTURB_KEYS=2 (deterministic/repeatable hash key randomization).
-Specifying PERL_PERTURB_KEYS explicitly to a different level overrides this
+C<PERL_HASH_SEED> implies a non-default C<PERL_PERTURB_KEYS> setting. Setting
+C<PERL_HASH_SEED=0> (exactly one 0) implies C<PERL_PERTURB_KEYS=0> (hash key
+randomization disabled); settng C<PERL_HASH_SEED> to any other value implies
+C<PERL_PERTURB_KEYS=2> (deterministic and repeatable hash key randomization).
+Specifying C<PERL_PERTURB_KEYS> explicitly to a different level overrides this
behavior.
=head3 Hash::Util::hash_seed() now returns a string
=head3 Output of PERL_HASH_SEED_DEBUG has been changed
The environment variable PERL_HASH_SEED_DEBUG now makes perl show both the
-hash function perl was built with AND the seed, in hex, in use for that
+hash function perl was built with, I<and> the seed, in hex, in use for that
process. Code parsing this output, should it exist, must change to accommodate
the new format. Example of the new format:
=head2 Upgrade to Unicode 6.2
-Perl now supports the final version of Unicode 6.2. Earlier releases in
-the 5.17 series supported Unicode 6.2 beta versions. There were no
-substantive changes in the final Unicode 6.2 version from the most
-recent beta, included in Perl 5.17.4. A list of changes from Unicode
+Perl now supports Unicode 6.2. A list of changes from Unicode
6.1 is at L<http://www.unicode.org/versions/Unicode6.2.0>.
=head2 Character name aliases may now include non-Latin1-range characters
use warnings "void";
$#; # void warning; no deprecation warning
-Now, the debugging, deprecated, glob, inplace and malloc warnings
+Now, the C<debugging>, C<deprecated>, C<glob>, C<inplace> and C<malloc> warnings
categories are left on when turning on lexical warnings (unless they are
turned off by C<no warnings>, of course).
of warnings.
Those are the only categories consisting only of default warnings. Default
-warnings in other categories are still disabled by C<use warnings
-"category">, as we do not yet have the infrastructure for controlling
+warnings in other categories are still disabled by C<< use warnings "category" >>,
+as we do not yet have the infrastructure for controlling
individual warnings.
=head2 C<state sub> and C<our sub>
=head2 C<gv_fetchmeth_*> and SUPER
The various C<gv_fetchmeth_*> XS functions used to treat a package whose
-named ended with ::SUPER specially. A method lookup on the Foo::SUPER
-package would be treated as a SUPER method lookup on the Foo package. This
-is no longer the case. To do a SUPER lookup, pass the Foo stash and the
-GV_SUPER flag.
+named ended with C<::SUPER> specially. A method lookup on the C<Foo::SUPER>
+package would be treated as a C<SUPER> method lookup on the C<Foo> package. This
+is no longer the case. To do a C<SUPER> lookup, pass the C<Foo> stash and the
+C<GV_SUPER> flag.
=head2 C<split>'s first argument is more consistently interpreted
The following modules will be removed from the core distribution in a
future release, and should be installed from CPAN instead. Distributions
on CPAN which require these should add them to their prerequisites.
-The core versions of these modules will issue "deprecated"-category
+The core versions of these modules will issue C<"deprecated">-category
warnings.
You can silence these deprecation warnings by installing the modules
with this in a future Perl version. In the meantime, use of any of the
missing characters will raise a deprecation warning, unless turned off.
The five characters are:
-U+0085 NEXT LINE,
-U+200E LEFT-TO-RIGHT MARK,
-U+200F RIGHT-TO-LEFT MARK,
-U+2028 LINE SEPARATOR,
+
+ U+0085 NEXT LINE,
+ U+200E LEFT-TO-RIGHT MARK,
+ U+200F RIGHT-TO-LEFT MARK,
+ U+2028 LINE SEPARATOR,
+
and
-U+2029 PARAGRAPH SEPARATOR.
+
+ U+2029 PARAGRAPH SEPARATOR.
=head2 User-defined charnames with surprising whitespace
compilers (e.g., gcc), compiling any file that uses any of these will
generate a warning. These were not intended for public use; there are
equivalent, faster, macros for most of them.
-See L<perlapi/Character classes>. The complete list (including some
-that were deprecated in 5.17.7) is:
+See L<perlapi/Character classes>. The complete list is:
C<is_uni_alnum>, C<is_uni_alnumc>, C<is_uni_alnumc_lc>,
C<is_uni_alnum_lc>, C<is_uni_alpha>, C<is_uni_alpha_lc>,
C<is_uni_ascii>, C<is_uni_ascii_lc>, C<is_uni_blank>,
deprecated:
C<to_uni_lower_lc>, C<to_uni_title_lc>, and C<to_uni_upper_lc>.
-=head2 Certain rare uses of backslashes within regexes are now deprectated
+=head2 Certain rare uses of backslashes within regexes are now deprecated
There are three pairs of characters that Perl recognizes as
metacharacters in regular expression patterns: C<{}>, C<[]>, and C<()>.
Since they are metacharacters, they have special meaning to regular
expression patterns, and it turns out that you can't turn off that
special meaning by the normal means of preceding them with a backslash,
-if you use them, paired, within a pattern delimitted by them. For
+if you use them, paired, within a pattern delimited by them. For
example, in
m{foo\{1,3\}}
Similarly, if the C<(> and C<*> are separated in C<(*VERB...)>
constructs.
+=head2 Pre-PerlIO IO implementations
+
+Perl supports being built without PerlIO proper, using a stdio or sfio
+wrapper instead. A perl build like this will not support IO layers and
+thus Unicode IO, making it rather handicapped.
+
+PerlIO supports a C<stdio> layer if stdio use is desired, and similarly a
+sfio layer could be produced.
+
=head1 Future Deprecations
=over
=item *
-Platforms with out support infrastructure
+Platforms without support infrastructure
Both Windows CE and z/OS have been historically under-maintained, and are
currently neither successfully building nor regularly being smoke tested.
=item *
-sfio, stdio
-
-Perl supports being built without PerlIO proper, using a stdio or sfio
-wrapper instead. A perl build like this will not support IO layers and
-thus Unicode IO, making it rather handicapped.
-
-PerlIO supports a C<stdio> layer if stdio use is desired, and similarly a
-sfio layer could be produced.
-
-=item *
-
C<microperl>, long broken and of unclear present purpose, will be removed.
=item *
=item *
-Apply the optimisation of hashes in boolean context, such as in C<if> or
-C<and>, to constructs in non-void context.
+The optimisation of hashes in boolean context has been extended to
+affect C<scalar(%hash)>, C<%hash ? ... : ...>, and C<sub { %hash || ... }>.
=item *
-Extend the optimisation of hashes in boolean context to C<scalar(%hash)>,
-C<%hash ? ... : ...>, and C<sub { %hash || ... }>.
-
-=item *
-
-Filetest ops manage the stack in a fractionally more efficient manner.
+Filetest operators manage the stack in a fractionally more efficient manner.
=item *
Globs used in a numeric context are now numified directly in most cases,
-rather than being numerified via stringification.
+rather than being numified via stringification.
=item *
This is only an overview of selected module updates. For a complete
list of updates, run:
- $ corelist --diff 5.14.0 5.16.0
+ $ corelist --diff 5.16.0 5.18.0
-You can substitute your favorite version in place of 5.14.0, too.
+You can substitute your favorite version in place of 5.16.0, too.
=over 4
x86_64-linux-5.13.6-thread-multi. It is unset by default.
This feature was requested by Tim Bunce, who observed that
-INSTALL_BASE creates a library structure that does not
+C<INSTALL_BASE> creates a library structure that does not
differentiate by perl version. Instead, it places architecture
specific files in "$install_base/lib/perl5/$archname". This makes
-it difficult to use a common INSTALL_BASE library path with
+it difficult to use a common C<INSTALL_BASE> library path with
multiple versions of perl.
-By setting -Duseversionedarchname, the $archname will be
+By setting C<-Duseversionedarchname>, the $archname will be
distinct for architecture I<and> API version, allowing mixed use of
-INSTALL_BASE.
+C<INSTALL_BASE>.
+
+=item *
+
+Add a C<PERL_NO_INLINE_FUNCTIONS> option
+
+If C<PERL_NO_INLINE_FUNCTIONS> is defined, don't include "inline.h"
+
+This permits test code to include the perl headers for definitions without
+creating a link dependency on the perl library (which may not exist yet).
=item *
The character set for Extended Filename Syntax (EFS) is now enabled by default
on VMS. Among other things, this provides better handling of dots in directory
-names, multiple dots in filenames,and spaces in filenames. To obtain the old
+names, multiple dots in filenames, and spaces in filenames. To obtain the old
behavior, set the logical name C<DECC$EFS_CHARSET> to C<DISABLE>.
=item *
-Fix linking on builds configured with -Dusemymalloc=y.
+Fixed linking on builds configured with C<-Dusemymalloc=y>.
=item *
-It should now be possible to compile Perl as C++ on VMS.
+Experimental support for building Perl with the HP C++ compiler is available
+by configuring with C<-Dusecxx>.
=item *
=item *
-The option to build without USE_SOCKETS_AS_HANDLES has been removed.
+The option to build without C<USE_SOCKETS_AS_HANDLES> has been removed.
=item *
=item *
-A new makefile option, USE_64_BIT_INT, has been added to the Windows
+A new makefile option, C<USE_64_BIT_INT>, has been added to the Windows
makefiles. Set this to "define" when building a 32-bit perl if you want
it to use 64-bit integers.
=item *
-Synonyms for the misleadingly named C<av_len()> has been created:
+Synonyms for the misleadingly named C<av_len()> have been created:
C<av_top_index()> and C<av_tindex>. All three of these return the
number of the highest index in the array, not the number of elements it
contains.
=item *
-PL_glob_index is gone.
+C<PL_glob_index> is gone.
=item *
optimiser will, where possible, substitute a single padrange op for a
pushmark followed by one or more pad ops, and possibly also skipping list
and nextstate ops. In addition, the op can carry out the tasks associated
-with the RHS of a my(...) = @_ assignment, so those ops may be optimised
+with the RHS of a C<< my(...) = @_ >> assignment, so those ops may be optimised
away too.
=item *
In the pluggable regex API, the C<regexp_engine> struct has acquired a new
field C<op_comp>, which is currently just for perl's internal use, and
-should be initialised to NULL by other regex plugin modules.
+should be initialized to NULL by other regex plugin modules.
=item *
=item *
Perl used to implement get magic in a way that would sometimes hide bugs in
-code could call mg_get() too many times on magical values. This hiding of
+code that could call mg_get() too many times on magical values. This hiding of
errors no longer occurs, so long-standing bugs may become visible now. If
you see magic-related errors in XS code, check to make sure it, together
with the Perl API functions it uses, calls mg_get() only once on SvGMAGICAL()
=item *
-PERL_DEBUG_READONLY_OPS has been rewritten to work with the new slab
+C<PERL_DEBUG_READONLY_OPS> has been rewritten to work with the new slab
allocator, allowing it to catch more violations than before.
=item *
-The old slab allocator for ops, which was only enabled for PERL_IMPLICIT_SYS
-and PERL_DEBUG_READONLY_OPS, has been retired.
+The old slab allocator for ops, which was only enabled for C<PERL_IMPLICIT_SYS>
+and C<PERL_DEBUG_READONLY_OPS>, has been retired.
=back
=item *
-
-DPERL_GLOBAL_STRUCT builds now free the global struct B<after>
+
C<-DPERL_GLOBAL_STRUCT> builds now free the global struct B<after>
they've finished using it.
=item *
C<$tied =~ s/$non_utf8/$utf8/> no longer loops infinitely if the tied
variable returns a Latin-1 string, shared hash key scalar, or reference or
-typeglob that stringifies as ASCII or Latin-1. This is a regression from
+typeglob that stringifies as ASCII or Latin-1. This was a regression from
5.12.x.
=item *
=item *
-Stash aliasing (C<*foo:: = *bar::>) no longer causes SUPER calls to ignore
+Stash aliasing (C<< *foo:: = *bar:: >>) no longer causes SUPER calls to ignore
changes to methods or @ISA or use the wrong package.
=item *
=item *
-The microperl build, broken since Perl 5.15.7, has now been restored.
-
-=item *
-
The code which generates errors from C<require()> could potentially read one or
two bytes before the start of the filename for filenames less than three bytes
long and ending C</\.p?\z/>. This has now been fixed. Note that it could
=item *
+Non-blocking sockets have been fixed on VMS.
+
+=item *
+
A bug in the compilation of a C</(?{})/> expression which affected the TryCatch
test suite has been fixed [perl #114242].
=item *
-Perl now works as well as can be expected on all releases of Unicode so
-far. In v5.16, it worked on Unicodes 6.0 and 6.1, but there were
-various bugs for earlier releases; the older the release the more
-problems.
+Perl now can be recompiled to use any Unicode version. In v5.16, it
+worked on Unicodes 6.0 and 6.1, but there were various bugs if earlier
+releases were used; the older the release the more problems.
=item *
=item *
Assigning a regular expression to a scalar containing a number no longer
-causes subsequent nummification to produce random numbers.
+causes subsequent numification to produce random numbers.
=item *
Assigning a regular expression to a magic variable no longer wipes away the
-magic. This is a regression from 5.10.
+magic. This was a regression from 5.10.
=item *
Assigning a regular expression to a blessed scalar no longer results in
-crashes. This is also a regression from 5.10.
+crashes. This was also a regression from 5.10.
=item *
=item *
-Nummifying a regular expression no longer results in an uninitialized
+Numifying a regular expression no longer results in an uninitialized
warning.
=item *
Negative array indices no longer cause EXISTS methods of tied variables to
-be ignored. This is a regression from 5.12.
+be ignored. This was a regression from 5.12.
=item *
https://perl5.git.perl.org / perl5.git / blobdiff