package feature;
-our $VERSION = '1.41';
+our $VERSION = '1.69';
our %feature = (
- fc => 'feature_fc',
- say => 'feature_say',
- state => 'feature_state',
- switch => 'feature_switch',
- bitwise => 'feature_bitwise',
- evalbytes => 'feature_evalbytes',
- postderef => 'feature_postderef',
- array_base => 'feature_arybase',
- signatures => 'feature_signatures',
- current_sub => 'feature___SUB__',
- refaliasing => 'feature_refaliasing',
- lexical_subs => 'feature_lexsubs',
- postderef_qq => 'feature_postderef_qq',
- unicode_eval => 'feature_unieval',
- unicode_strings => 'feature_unicode',
+ fc => 'feature_fc',
+ isa => 'feature_isa',
+ say => 'feature_say',
+ try => 'feature_try',
+ defer => 'feature_defer',
+ state => 'feature_state',
+ switch => 'feature_switch',
+ bitwise => 'feature_bitwise',
+ indirect => 'feature_indirect',
+ evalbytes => 'feature_evalbytes',
+ signatures => 'feature_signatures',
+ current_sub => 'feature___SUB__',
+ refaliasing => 'feature_refaliasing',
+ postderef_qq => 'feature_postderef_qq',
+ unicode_eval => 'feature_unieval',
+ declared_refs => 'feature_myref',
+ unicode_strings => 'feature_unicode',
+ multidimensional => 'feature_multidimensional',
+ bareword_filehandles => 'feature_bareword_filehandles',
);
our %feature_bundle = (
- "5.10" => [qw(array_base say state switch)],
- "5.11" => [qw(array_base say state switch unicode_strings)],
- "5.15" => [qw(current_sub evalbytes fc say state switch unicode_eval unicode_strings)],
- "all" => [qw(array_base bitwise current_sub evalbytes fc lexical_subs postderef postderef_qq refaliasing say signatures state switch unicode_eval unicode_strings)],
- "default" => [qw(array_base)],
+ "5.10" => [qw(bareword_filehandles indirect multidimensional say state switch)],
+ "5.11" => [qw(bareword_filehandles indirect multidimensional say state switch unicode_strings)],
+ "5.15" => [qw(bareword_filehandles current_sub evalbytes fc indirect multidimensional say state switch unicode_eval unicode_strings)],
+ "5.23" => [qw(bareword_filehandles current_sub evalbytes fc indirect multidimensional postderef_qq say state switch unicode_eval unicode_strings)],
+ "5.27" => [qw(bareword_filehandles bitwise current_sub evalbytes fc indirect multidimensional postderef_qq say state switch unicode_eval unicode_strings)],
+ "5.35" => [qw(bitwise current_sub evalbytes fc postderef_qq say state unicode_eval unicode_strings)],
+ "all" => [qw(bareword_filehandles bitwise current_sub declared_refs defer evalbytes fc indirect isa multidimensional postderef_qq refaliasing say signatures state switch try unicode_eval unicode_strings)],
+ "default" => [qw(bareword_filehandles indirect multidimensional)],
);
$feature_bundle{"5.12"} = $feature_bundle{"5.11"};
$feature_bundle{"5.20"} = $feature_bundle{"5.15"};
$feature_bundle{"5.21"} = $feature_bundle{"5.15"};
$feature_bundle{"5.22"} = $feature_bundle{"5.15"};
-$feature_bundle{"5.23"} = $feature_bundle{"5.15"};
-$feature_bundle{"5.24"} = $feature_bundle{"5.15"};
+$feature_bundle{"5.24"} = $feature_bundle{"5.23"};
+$feature_bundle{"5.25"} = $feature_bundle{"5.23"};
+$feature_bundle{"5.26"} = $feature_bundle{"5.23"};
+$feature_bundle{"5.28"} = $feature_bundle{"5.27"};
+$feature_bundle{"5.29"} = $feature_bundle{"5.27"};
+$feature_bundle{"5.30"} = $feature_bundle{"5.27"};
+$feature_bundle{"5.31"} = $feature_bundle{"5.27"};
+$feature_bundle{"5.32"} = $feature_bundle{"5.27"};
+$feature_bundle{"5.33"} = $feature_bundle{"5.27"};
+$feature_bundle{"5.34"} = $feature_bundle{"5.27"};
+$feature_bundle{"5.36"} = $feature_bundle{"5.35"};
$feature_bundle{"5.9.5"} = $feature_bundle{"5.10"};
+my %noops = (
+ postderef => 1,
+ lexical_subs => 1,
+);
+my %removed = (
+ array_base => 1,
+);
our $hint_shift = 26;
-our $hint_mask = 0x1c000000;
-our @hint_bundles = qw( default 5.10 5.11 5.15 );
+our $hint_mask = 0x3c000000;
+our @hint_bundles = qw( default 5.10 5.11 5.15 5.23 5.27 5.35 );
# This gets set (for now) in $^H as well as in %^H,
# for runtime speed of the uc/lc/ucfirst/lcfirst functions.
=head1 SYNOPSIS
- use feature qw(say switch);
- given ($foo) {
- when (1) { say "\$foo == 1" }
- when ([2,3]) { say "\$foo == 2 || \$foo == 3" }
- when (/^a[bc]d$/) { say "\$foo eq 'abd' || \$foo eq 'acd'" }
- when ($_ > 100) { say "\$foo > 100" }
- default { say "None of the above" }
- }
+ use feature qw(fc say);
+
+ # Without the "use feature" above, this code would not be able to find
+ # the built-ins "say" or "fc":
+ say "The case-folded version of $x is: " . fc $x;
- use feature ':5.10'; # loads all features available in perl 5.10
- use v5.10; # implicitly loads :5.10 feature bundle
+ # set features to match the :5.10 bundle, which may turn off or on
+ # multiple features (see below)
+ use feature ':5.10';
+
+
+ # implicitly loads :5.10 feature bundle
+ use v5.10;
=head1 DESCRIPTION
=head2 The 'say' feature
-C<use feature 'say'> tells the compiler to enable the Perl 6 style
+C<use feature 'say'> tells the compiler to enable the Raku-inspired
C<say> function.
See L<perlfunc/say> for details.
=head2 The 'switch' feature
-B<WARNING>: Because the L<smartmatch operator|perlop/"Smartmatch Operator"> is
-experimental, Perl will warn when you use this feature, unless you have
-explicitly disabled the warning:
+B<WARNING>: This feature is still experimental and the implementation may
+change or be removed in future versions of Perl. For this reason, Perl will
+warn when you use the feature, unless you have explicitly disabled the warning:
no warnings "experimental::smartmatch";
-C<use feature 'switch'> tells the compiler to enable the Perl 6
+C<use feature 'switch'> tells the compiler to enable the Raku
given/when construct.
See L<perlsyn/"Switch Statements"> for details.
C<use feature 'unicode_strings'> subpragma is B<strongly> recommended.
This feature is available starting with Perl 5.12; was almost fully
-implemented in Perl 5.14; and extended in Perl 5.16 to cover C<quotemeta>.
+implemented in Perl 5.14; and extended in Perl 5.16 to cover C<quotemeta>;
+was extended further in Perl 5.26 to cover L<the range
+operator|perlop/Range Operators>; and was extended again in Perl 5.28 to
+cover L<special-cased whitespace splitting|perlfunc/split>.
=head2 The 'unicode_eval' and 'evalbytes' features
-Under the C<unicode_eval> feature, Perl's C<eval> function, when passed a
-string, will evaluate it as a string of characters, ignoring any
-C<use utf8> declarations. C<use utf8> exists to declare the encoding of
-the script, which only makes sense for a stream of bytes, not a string of
-characters. Source filters are forbidden, as they also really only make
-sense on strings of bytes. Any attempt to activate a source filter will
-result in an error.
-
-The C<evalbytes> feature enables the C<evalbytes> keyword, which evaluates
-the argument passed to it as a string of bytes. It dies if the string
-contains any characters outside the 8-bit range. Source filters work
-within C<evalbytes>: they apply to the contents of the string being
-evaluated.
-
-Together, these two features are intended to replace the historical C<eval>
-function, which has (at least) two bugs in it, that cannot easily be fixed
-without breaking existing programs:
-
-=over
-
-=item *
-
-C<eval> behaves differently depending on the internal encoding of the
-string, sometimes treating its argument as a string of bytes, and sometimes
-as a string of characters.
+Together, these two features are intended to replace the legacy string
+C<eval> function, which behaves problematically in some instances. They are
+available starting with Perl 5.16, and are enabled by default by a
+S<C<use 5.16>> or higher declaration.
-=item *
-
-Source filters activated within C<eval> leak out into whichever I<file>
-scope is currently being compiled. To give an example with the CPAN module
-L<Semi::Semicolons>:
-
- BEGIN { eval "use Semi::Semicolons; # not filtered here " }
- # filtered here!
-
-C<evalbytes> fixes that to work the way one would expect:
+C<unicode_eval> changes the behavior of plain string C<eval> to work more
+consistently, especially in the Unicode world. Certain (mis)behaviors
+couldn't be changed without breaking some things that had come to rely on
+them, so the feature can be enabled and disabled. Details are at
+L<perlfunc/Under the "unicode_eval" feature>.
- use feature "evalbytes";
- BEGIN { evalbytes "use Semi::Semicolons; # filtered " }
- # not filtered
-
-=back
-
-These two features are available starting with Perl 5.16.
+C<evalbytes> is like string C<eval>, but it treats its argument as a byte
+string. Details are at L<perlfunc/evalbytes EXPR>. Without a
+S<C<use feature 'evalbytes'>> nor a S<C<use v5.16>> (or higher) declaration in
+the current scope, you can still access it by instead writing
+C<CORE::evalbytes>.
=head2 The 'current_sub' feature
=head2 The 'array_base' feature
-This feature supports the legacy C<$[> variable. See L<perlvar/$[> and
-L<arybase>. It is on by default but disabled under C<use v5.16> (see
-L</IMPLICIT LOADING>, below).
+This feature supported the legacy C<$[> variable. See L<perlvar/$[>.
+It was on by default but disabled under C<use v5.16> (see
+L</IMPLICIT LOADING>, below) and unavailable since perl 5.30.
This feature is available under this name starting with Perl 5.16. In
previous versions, it was simply on all the time, and this pragma knew
=head2 The 'lexical_subs' feature
-B<WARNING>: This feature is still experimental and the implementation may
-change in future versions of Perl. For this reason, Perl will
-warn when you use the feature, unless you have explicitly disabled the
-warning:
+In Perl versions prior to 5.26, this feature enabled
+declaration of subroutines via C<my sub foo>, C<state sub foo>
+and C<our sub foo> syntax. See L<perlsub/Lexical Subroutines> for details.
- no warnings "experimental::lexical_subs";
+This feature is available from Perl 5.18 onwards. From Perl 5.18 to 5.24,
+it was classed as experimental, and Perl emitted a warning for its
+usage, except when explicitly disabled:
-This enables declaration of subroutines via C<my sub foo>, C<state sub foo>
-and C<our sub foo> syntax. See L<perlsub/Lexical Subroutines> for details.
+ no warnings "experimental::lexical_subs";
-This feature is available from Perl 5.18 onwards.
+As of Perl 5.26, use of this feature no longer triggers a warning, though
+the C<experimental::lexical_subs> warning category still exists (for
+compatibility with code that disables it). In addition, this syntax is
+not only no longer experimental, but it is enabled for all Perl code,
+regardless of what feature declarations are in scope.
=head2 The 'postderef' and 'postderef_qq' features
-B<WARNING>: This feature is still experimental and the implementation may
-change in future versions of Perl. For this reason, Perl will
-warn when you use the feature, unless you have explicitly disabled the
-warning:
+The 'postderef_qq' feature extends the applicability of L<postfix
+dereference syntax|perlref/Postfix Dereference Syntax> so that postfix array
+and scalar dereference are available in double-quotish interpolations. For
+example, it makes the following two statements equivalent:
- no warnings "experimental::postderef";
+ my $s = "[@{ $h->{a} }]";
+ my $s = "[$h->{a}->@*]";
-The 'postderef' feature allows the use of L<postfix dereference
-syntax|perlref/Postfix Dereference Syntax>. For example, it will make the
-following two statements equivalent:
+This feature is available from Perl 5.20 onwards. In Perl 5.20 and 5.22, it
+was classed as experimental, and Perl emitted a warning for its
+usage, except when explicitly disabled:
- my @x = @{ $h->{a} };
- my @x = $h->{a}->@*;
+ no warnings "experimental::postderef";
-The 'postderef_qq' feature extends this, for array and scalar dereference, to
-working inside of double-quotish interpolations.
+As of Perl 5.24, use of this feature no longer triggers a warning, though
+the C<experimental::postderef> warning category still exists (for
+compatibility with code that disables it).
-This feature is available from Perl 5.20 onwards.
+The 'postderef' feature was used in Perl 5.20 and Perl 5.22 to enable
+postfix dereference syntax outside double-quotish interpolations. In those
+versions, using it triggered the C<experimental::postderef> warning in the
+same way as the 'postderef_qq' feature did. As of Perl 5.24, this syntax is
+not only no longer experimental, but it is enabled for all Perl code,
+regardless of what feature declarations are in scope.
=head2 The 'signatures' feature
B<WARNING>: This feature is still experimental and the implementation may
-change in future versions of Perl. For this reason, Perl will
-warn when you use the feature, unless you have explicitly disabled the
-warning:
+change or be removed in future versions of Perl. For this reason, Perl will
+warn when you use the feature, unless you have explicitly disabled the warning:
no warnings "experimental::signatures";
=head2 The 'refaliasing' feature
B<WARNING>: This feature is still experimental and the implementation may
-change in future versions of Perl. For this reason, Perl will
-warn when you use the feature, unless you have explicitly disabled the
-warning:
+change or be removed in future versions of Perl. For this reason, Perl will
+warn when you use the feature, unless you have explicitly disabled the warning:
no warnings "experimental::refaliasing";
=head2 The 'bitwise' feature
-B<WARNING>: This feature is still experimental and the implementation may
-change in future versions of Perl. For this reason, Perl will
-warn when you use the feature, unless you have explicitly disabled the
-warning:
-
- no warnings "experimental::bitwise";
-
This makes the four standard bitwise operators (C<& | ^ ~>) treat their
operands consistently as numbers, and introduces four new dotted operators
(C<&. |. ^. ~.>) that treat their operands consistently as strings. The
See L<perlop/Bitwise String Operators> for details.
-This feature is available from Perl 5.22 onwards.
+This feature is available from Perl 5.22 onwards. Starting in Perl 5.28,
+C<use v5.28> will enable the feature. Before 5.28, it was still
+experimental and would emit a warning in the "experimental::bitwise"
+category.
-=head1 FEATURE BUNDLES
+=head2 The 'declared_refs' feature
-It's possible to load multiple features together, using
-a I<feature bundle>. The name of a feature bundle is prefixed with
-a colon, to distinguish it from an actual feature.
+B<WARNING>: This feature is still experimental and the implementation may
+change or be removed in future versions of Perl. For this reason, Perl will
+warn when you use the feature, unless you have explicitly disabled the warning:
- use feature ":5.10";
+ no warnings "experimental::declared_refs";
-The following feature bundles are available:
+This allows a reference to a variable to be declared with C<my>, C<state>,
+our C<our>, or localized with C<local>. It is intended mainly for use in
+conjunction with the "refaliasing" feature. See L<perlref/Declaring a
+Reference to a Variable> for examples.
- bundle features included
- --------- -----------------
- :default array_base
+This feature is available from Perl 5.26 onwards.
+
+=head2 The 'isa' feature
+
+This allows the use of the C<isa> infix operator, which tests whether the
+scalar given by the left operand is an object of the class given by the
+right operand. See L<perlop/Class Instance Operator> for more details.
+
+This feature is available from Perl 5.32 onwards. From Perl 5.32 to 5.34,
+it was classed as experimental, and Perl emitted a warning for its usage,
+except when explicitly disabled:
- :5.10 say state switch array_base
+ no warnings "experimental::isa";
- :5.12 say state switch unicode_strings array_base
+As of Perl 5.36, use of this feature no longer triggers a warning (though the
+C<experimental::isa> warning category stilll exists for compatibility with
+code that disables it).
- :5.14 say state switch unicode_strings array_base
+=head2 The 'indirect' feature
+
+This feature allows the use of L<indirect object
+syntax|perlobj/Indirect Object Syntax> for method calls, e.g. C<new
+Foo 1, 2;>. It is enabled by default, but can be turned off to
+disallow indirect object syntax.
+
+This feature is available under this name from Perl 5.32 onwards. In
+previous versions, it was simply on all the time. To disallow (or
+warn on) indirect object syntax on older Perls, see the L<indirect>
+CPAN module.
+
+=head2 The 'multidimensional' feature
+
+This feature enables multidimensional array emulation, a perl 4 (or
+earlier) feature that was used to emulate multidimensional arrays with
+hashes. This works by converting code like C<< $foo{$x, $y} >> into
+C<< $foo{join($;, $x, $y)} >>. It is enabled by default, but can be
+turned off to disable multidimensional array emulation.
+
+When this feature is disabled the syntax that is normally replaced
+will report a compilation error.
+
+This feature is available under this name from Perl 5.34 onwards. In
+previous versions, it was simply on all the time.
+
+You can use the L<multidimensional> module on CPAN to disable
+multidimensional array emulation for older versions of Perl.
+
+=head2 The 'bareword_filehandles' feature.
+
+This feature enables bareword filehandles for builtin functions
+operations, a generally discouraged practice. It is enabled by
+default, but can be turned off to disable bareword filehandles, except
+for the exceptions listed below.
+
+The perl built-in filehandles C<STDIN>, C<STDOUT>, C<STDERR>, C<DATA>,
+C<ARGV>, C<ARGVOUT> and the special C<_> are always enabled.
+
+This behavior was always present in versions before Perl 5.34. In Perl 5.34,
+it was made controllable with the C<feature> pragma, but was on by default.
+It is not present in the C<:5.36> feature bundle, so C<use v5.36> disables
+this feature.
+
+You can use the L<bareword::filehandles> module on CPAN to disable
+bareword filehandles for older versions of perl.
+
+=head2 The 'try' feature.
+
+B<WARNING>: This feature is still experimental and the implementation may
+change or be removed in future versions of Perl. For this reason, Perl will
+warn when you use the feature, unless you have explicitly disabled the warning:
- :5.16 say state switch unicode_strings
- unicode_eval evalbytes current_sub fc
+ no warnings "experimental::try";
- :5.18 say state switch unicode_strings
- unicode_eval evalbytes current_sub fc
+This feature enables the C<try> and C<catch> syntax, which allows exception
+handling, where exceptions thrown from the body of the block introduced with
+C<try> are caught by executing the body of the C<catch> block.
- :5.20 say state switch unicode_strings
- unicode_eval evalbytes current_sub fc
+For more information, see L<perlsyn/"Try Catch Exception Handling">.
- :5.22 say state switch unicode_strings
- unicode_eval evalbytes current_sub fc
+=head2 The 'defer' feature
- :5.24 say state switch unicode_strings
- unicode_eval evalbytes current_sub fc
+This feature enables the C<defer> block syntax, which allows a block of code
+to be deferred until when the flow of control leaves the block which contained
+it. For more details, see L<perlsyn/defer>.
+
+=head1 FEATURE BUNDLES
+
+It's possible to load multiple features together, using
+a I<feature bundle>. The name of a feature bundle is prefixed with
+a colon, to distinguish it from an actual feature.
+
+ use feature ":5.10";
+
+The following feature bundles are available:
+
+ bundle features included
+ --------- -----------------
+ :default indirect multidimensional
+ bareword_filehandles
+
+ :5.10 bareword_filehandles indirect
+ multidimensional say state switch
+
+ :5.12 bareword_filehandles indirect
+ multidimensional say state switch
+ unicode_strings
+
+ :5.14 bareword_filehandles indirect
+ multidimensional say state switch
+ unicode_strings
+
+ :5.16 bareword_filehandles current_sub evalbytes
+ fc indirect multidimensional say state
+ switch unicode_eval unicode_strings
+
+ :5.18 bareword_filehandles current_sub evalbytes
+ fc indirect multidimensional say state
+ switch unicode_eval unicode_strings
+
+ :5.20 bareword_filehandles current_sub evalbytes
+ fc indirect multidimensional say state
+ switch unicode_eval unicode_strings
+
+ :5.22 bareword_filehandles current_sub evalbytes
+ fc indirect multidimensional say state
+ switch unicode_eval unicode_strings
+
+ :5.24 bareword_filehandles current_sub evalbytes
+ fc indirect multidimensional postderef_qq
+ say state switch unicode_eval
+ unicode_strings
+
+ :5.26 bareword_filehandles current_sub evalbytes
+ fc indirect multidimensional postderef_qq
+ say state switch unicode_eval
+ unicode_strings
+
+ :5.28 bareword_filehandles bitwise current_sub
+ evalbytes fc indirect multidimensional
+ postderef_qq say state switch unicode_eval
+ unicode_strings
+
+ :5.30 bareword_filehandles bitwise current_sub
+ evalbytes fc indirect multidimensional
+ postderef_qq say state switch unicode_eval
+ unicode_strings
+
+ :5.32 bareword_filehandles bitwise current_sub
+ evalbytes fc indirect multidimensional
+ postderef_qq say state switch unicode_eval
+ unicode_strings
+
+ :5.34 bareword_filehandles bitwise current_sub
+ evalbytes fc indirect multidimensional
+ postderef_qq say state switch unicode_eval
+ unicode_strings
+
+ :5.36 bitwise current_sub evalbytes fc
+ postderef_qq say state unicode_eval
+ unicode_strings
The C<:default> bundle represents the feature set that is enabled before
any C<use feature> or C<no feature> declaration.
If the required version is older than Perl 5.10, the ":default" feature
bundle is automatically loaded instead.
+Unlike C<use feature ":5.12">, saying C<use v5.12> (or any higher version)
+also does the equivalent of C<use strict>; see L<perlfunc/use> for details.
+
+=back
+
+=head1 CHECKING FEATURES
+
+C<feature> provides some simple APIs to check which features are enabled.
+
+These functions cannot be imported and must be called by their fully
+qualified names. If you don't otherwise need to set a feature you will
+need to ensure C<feature> is loaded with:
+
+ use feature ();
+
+=over
+
+=item feature_enabled($feature)
+
+=item feature_enabled($feature, $depth)
+
+ package MyStandardEnforcer;
+ use feature ();
+ use Carp "croak";
+ sub import {
+ croak "disable indirect!" if feature::feature_enabled("indirect");
+ }
+
+Test whether a named feature is enabled at a given level in the call
+stack, returning a true value if it is. C<$depth> defaults to 1,
+which checks the scope that called the scope calling
+feature::feature_enabled().
+
+croaks for an unknown feature name.
+
+=item features_enabled()
+
+=item features_enabled($depth)
+
+ package ReportEnabledFeatures;
+ use feature "say";
+ sub import {
+ say STDERR join " ", feature::features_enabled();
+ }
+
+Returns a list of the features enabled at a given level in the call
+stack. C<$depth> defaults to 1, which checks the scope that called
+the scope calling feature::features_enabled().
+
+=item feature_bundle()
+
+=item feature_bundle($depth)
+
+Returns the feature bundle, if any, selected at a given level in the
+call stack. C<$depth> defaults to 1, which checks the scope that called
+the scope calling feature::feature_bundle().
+
+Returns an undefined value if no feature bundle is selected in the
+scope.
+
+The bundle name returned will be for the earliest bundle matching the
+selected bundle, so:
+
+ use feature ();
+ use v5.12;
+ BEGIN { print feature::feature_bundle(0); }
+
+will print C<5.11>.
+
+This returns internal state, at this point C<use v5.12;> sets the
+feature bundle, but C< use feature ":5.12"; > does not set the feature
+bundle. This may change in a future release of perl.
+
=back
=cut
my $import = shift;
my $bundle_number = $^H & $hint_mask;
my $features = $bundle_number != $hint_mask
- && $feature_bundle{$hint_bundles[$bundle_number >> $hint_shift]};
+ && $feature_bundle{$hint_bundles[$bundle_number >> $hint_shift]};
if ($features) {
# Features are enabled implicitly via bundle hints.
# Delete any keys that may be left over from last time.
next;
}
if (!exists $feature{$name}) {
+ if (exists $noops{$name}) {
+ next;
+ }
+ if (!$import && exists $removed{$name}) {
+ next;
+ }
unknown_feature($name);
}
if ($import) {
Carp::croak(@_);
}
+sub features_enabled {
+ my ($depth) = @_;
+
+ $depth //= 1;
+ my @frame = caller($depth+1)
+ or return;
+ my ($hints, $hinthash) = @frame[8, 10];
+
+ my $bundle_number = $hints & $hint_mask;
+ if ($bundle_number != $hint_mask) {
+ return $feature_bundle{$hint_bundles[$bundle_number >> $hint_shift]}->@*;
+ }
+ else {
+ my @features;
+ for my $feature (sort keys %feature) {
+ if ($hinthash->{$feature{$feature}}) {
+ push @features, $feature;
+ }
+ }
+ return @features;
+ }
+}
+
+sub feature_enabled {
+ my ($feature, $depth) = @_;
+
+ $depth //= 1;
+ my @frame = caller($depth+1)
+ or return;
+ my ($hints, $hinthash) = @frame[8, 10];
+
+ my $hint_feature = $feature{$feature}
+ or croak "Unknown feature $feature";
+ my $bundle_number = $hints & $hint_mask;
+ if ($bundle_number != $hint_mask) {
+ my $bundle = $hint_bundles[$bundle_number >> $hint_shift];
+ for my $bundle_feature ($feature_bundle{$bundle}->@*) {
+ return 1 if $bundle_feature eq $feature;
+ }
+ return 0;
+ }
+ else {
+ return $hinthash->{$hint_feature} // 0;
+ }
+}
+
+sub feature_bundle {
+ my $depth = shift;
+
+ $depth //= 1;
+ my @frame = caller($depth+1)
+ or return;
+ my $bundle_number = $frame[8] & $hint_mask;
+ if ($bundle_number != $hint_mask) {
+ return $hint_bundles[$bundle_number >> $hint_shift];
+ }
+ else {
+ return undef;
+ }
+}
+
1;
# ex: set ro:
https://perl5.git.perl.org / perl5.git / blobdiff