diff options
Diffstat (limited to 'gnu/usr.bin/perl/lib/feature.pm')
| -rw-r--r-- | gnu/usr.bin/perl/lib/feature.pm | 140 |
1 files changed, 76 insertions, 64 deletions
diff --git a/gnu/usr.bin/perl/lib/feature.pm b/gnu/usr.bin/perl/lib/feature.pm index ec9fff7a6d4..6466eb70c65 100644 --- a/gnu/usr.bin/perl/lib/feature.pm +++ b/gnu/usr.bin/perl/lib/feature.pm @@ -5,7 +5,7 @@ package feature; -our $VERSION = '1.42'; +our $VERSION = '1.52'; our %feature = ( fc => 'feature_fc', @@ -14,14 +14,13 @@ our %feature = ( 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', + declared_refs => 'feature_myref', unicode_strings => 'feature_unicode', ); @@ -30,7 +29,8 @@ our %feature_bundle = ( "5.11" => [qw(array_base say state switch unicode_strings)], "5.15" => [qw(current_sub evalbytes fc say state switch unicode_eval unicode_strings)], "5.23" => [qw(current_sub evalbytes fc postderef_qq 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)], + "5.27" => [qw(bitwise current_sub evalbytes fc postderef_qq say state switch unicode_eval unicode_strings)], + "all" => [qw(array_base bitwise current_sub declared_refs evalbytes fc postderef_qq refaliasing say signatures state switch unicode_eval unicode_strings)], "default" => [qw(array_base)], ); @@ -45,11 +45,18 @@ $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{"5.24"} = $feature_bundle{"5.23"}; +$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{"5.9.5"} = $feature_bundle{"5.10"}; +my %noops = ( + postderef => 1, + lexical_subs => 1, +); our $hint_shift = 26; our $hint_mask = 0x1c000000; -our @hint_bundles = qw( default 5.10 5.11 5.15 5.23 ); +our @hint_bundles = qw( default 5.10 5.11 5.15 5.23 5.27 ); # This gets set (for now) in $^H as well as in %^H, # for runtime speed of the uc/lc/ucfirst/lcfirst functions. @@ -169,54 +176,29 @@ potentially using Unicode in your program, the 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. - -=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! +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. -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 operating on a byte stream that is +not UTF-8 encoded. 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 @@ -246,17 +228,21 @@ This feature is available from Perl 5.16 onwards. =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 @@ -330,13 +316,6 @@ This feature is available from Perl 5.22 onwards. =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 @@ -344,7 +323,26 @@ same applies to the assignment variants (C<&= |= ^= &.= |.= ^.=>). 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. + +=head2 The 'declared_refs' 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::declared_refs"; + +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. + +This feature is available from Perl 5.26 onwards. =head1 FEATURE BUNDLES @@ -382,6 +380,14 @@ The following feature bundles are available: unicode_eval evalbytes current_sub fc postderef_qq + :5.26 say state switch unicode_strings + unicode_eval evalbytes current_sub fc + postderef_qq + + :5.28 say state switch unicode_strings + unicode_eval evalbytes current_sub fc + postderef_qq bitwise + The C<:default> bundle represents the feature set that is enabled before any C<use feature> or C<no feature> declaration. @@ -431,6 +437,9 @@ with the same effect. 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 =cut @@ -487,6 +496,9 @@ sub __common { next; } if (!exists $feature{$name}) { + if (exists $noops{$name}) { + next; + } unknown_feature($name); } if ($import) { |