| 1 | | | | | # -*- buffer-read-only: t -*- |
| 2 | | | | | # !!!!!!! DO NOT EDIT THIS FILE !!!!!!! |
| 3 | | | | | # This file is built by regen/feature.pl. |
| 4 | | | | | # Any changes made here will be lost! |
| 5 | | | | | |
| 6 | | | | | package feature; |
| 7 | | | | | |
| 8 | 1 | 1µs | | | our $VERSION = '1.40'; |
| 9 | | | | | |
| 10 | 1 | 9µs | | | our %feature = ( |
| 11 | | | | | fc => 'feature_fc', |
| 12 | | | | | say => 'feature_say', |
| 13 | | | | | state => 'feature_state', |
| 14 | | | | | switch => 'feature_switch', |
| 15 | | | | | bitwise => 'feature_bitwise', |
| 16 | | | | | evalbytes => 'feature_evalbytes', |
| 17 | | | | | postderef => 'feature_postderef', |
| 18 | | | | | array_base => 'feature_arybase', |
| 19 | | | | | signatures => 'feature_signatures', |
| 20 | | | | | current_sub => 'feature___SUB__', |
| 21 | | | | | refaliasing => 'feature_refaliasing', |
| 22 | | | | | lexical_subs => 'feature_lexsubs', |
| 23 | | | | | postderef_qq => 'feature_postderef_qq', |
| 24 | | | | | unicode_eval => 'feature_unieval', |
| 25 | | | | | unicode_strings => 'feature_unicode', |
| 26 | | | | | ); |
| 27 | | | | | |
| 28 | 1 | 7µs | | | our %feature_bundle = ( |
| 29 | | | | | "5.10" => [qw(array_base say state switch)], |
| 30 | | | | | "5.11" => [qw(array_base say state switch unicode_strings)], |
| 31 | | | | | "5.15" => [qw(current_sub evalbytes fc say state switch unicode_eval unicode_strings)], |
| 32 | | | | | "all" => [qw(array_base bitwise current_sub evalbytes fc lexical_subs postderef postderef_qq refaliasing say signatures state switch unicode_eval unicode_strings)], |
| 33 | | | | | "default" => [qw(array_base)], |
| 34 | | | | | ); |
| 35 | | | | | |
| 36 | 1 | 1µs | | | $feature_bundle{"5.12"} = $feature_bundle{"5.11"}; |
| 37 | 1 | 400ns | | | $feature_bundle{"5.13"} = $feature_bundle{"5.11"}; |
| 38 | 1 | 800ns | | | $feature_bundle{"5.14"} = $feature_bundle{"5.11"}; |
| 39 | 1 | 300ns | | | $feature_bundle{"5.16"} = $feature_bundle{"5.15"}; |
| 40 | 1 | 200ns | | | $feature_bundle{"5.17"} = $feature_bundle{"5.15"}; |
| 41 | 1 | 200ns | | | $feature_bundle{"5.18"} = $feature_bundle{"5.15"}; |
| 42 | 1 | 300ns | | | $feature_bundle{"5.19"} = $feature_bundle{"5.15"}; |
| 43 | 1 | 200ns | | | $feature_bundle{"5.20"} = $feature_bundle{"5.15"}; |
| 44 | 1 | 300ns | | | $feature_bundle{"5.21"} = $feature_bundle{"5.15"}; |
| 45 | 1 | 200ns | | | $feature_bundle{"5.22"} = $feature_bundle{"5.15"}; |
| 46 | 1 | 1µs | | | $feature_bundle{"5.9.5"} = $feature_bundle{"5.10"}; |
| 47 | | | | | |
| 48 | 1 | 300ns | | | our $hint_shift = 26; |
| 49 | 1 | 100ns | | | our $hint_mask = 0x1c000000; |
| 50 | 1 | 2µs | | | our @hint_bundles = qw( default 5.10 5.11 5.15 ); |
| 51 | | | | | |
| 52 | | | | | # This gets set (for now) in $^H as well as in %^H, |
| 53 | | | | | # for runtime speed of the uc/lc/ucfirst/lcfirst functions. |
| 54 | | | | | # See HINT_UNI_8_BIT in perl.h. |
| 55 | 1 | 200ns | | | our $hint_uni8bit = 0x00000800; |
| 56 | | | | | |
| 57 | | | | | # TODO: |
| 58 | | | | | # - think about versioned features (use feature switch => 2) |
| 59 | | | | | |
| 60 | | | | | =head1 NAME |
| 61 | | | | | |
| 62 | | | | | feature - Perl pragma to enable new features |
| 63 | | | | | |
| 64 | | | | | =head1 SYNOPSIS |
| 65 | | | | | |
| 66 | | | | | use feature qw(say switch); |
| 67 | | | | | given ($foo) { |
| 68 | | | | | when (1) { say "\$foo == 1" } |
| 69 | | | | | when ([2,3]) { say "\$foo == 2 || \$foo == 3" } |
| 70 | | | | | when (/^a[bc]d$/) { say "\$foo eq 'abd' || \$foo eq 'acd'" } |
| 71 | | | | | when ($_ > 100) { say "\$foo > 100" } |
| 72 | | | | | default { say "None of the above" } |
| 73 | | | | | } |
| 74 | | | | | |
| 75 | | | | | use feature ':5.10'; # loads all features available in perl 5.10 |
| 76 | | | | | |
| 77 | | | | | use v5.10; # implicitly loads :5.10 feature bundle |
| 78 | | | | | |
| 79 | | | | | =head1 DESCRIPTION |
| 80 | | | | | |
| 81 | | | | | It is usually impossible to add new syntax to Perl without breaking |
| 82 | | | | | some existing programs. This pragma provides a way to minimize that |
| 83 | | | | | risk. New syntactic constructs, or new semantic meanings to older |
| 84 | | | | | constructs, can be enabled by C<use feature 'foo'>, and will be parsed |
| 85 | | | | | only when the appropriate feature pragma is in scope. (Nevertheless, the |
| 86 | | | | | C<CORE::> prefix provides access to all Perl keywords, regardless of this |
| 87 | | | | | pragma.) |
| 88 | | | | | |
| 89 | | | | | =head2 Lexical effect |
| 90 | | | | | |
| 91 | | | | | Like other pragmas (C<use strict>, for example), features have a lexical |
| 92 | | | | | effect. C<use feature qw(foo)> will only make the feature "foo" available |
| 93 | | | | | from that point to the end of the enclosing block. |
| 94 | | | | | |
| 95 | | | | | { |
| 96 | | | | | use feature 'say'; |
| 97 | | | | | say "say is available here"; |
| 98 | | | | | } |
| 99 | | | | | print "But not here.\n"; |
| 100 | | | | | |
| 101 | | | | | =head2 C<no feature> |
| 102 | | | | | |
| 103 | | | | | Features can also be turned off by using C<no feature "foo">. This too |
| 104 | | | | | has lexical effect. |
| 105 | | | | | |
| 106 | | | | | use feature 'say'; |
| 107 | | | | | say "say is available here"; |
| 108 | | | | | { |
| 109 | | | | | no feature 'say'; |
| 110 | | | | | print "But not here.\n"; |
| 111 | | | | | } |
| 112 | | | | | say "Yet it is here."; |
| 113 | | | | | |
| 114 | | | | | C<no feature> with no features specified will reset to the default group. To |
| 115 | | | | | disable I<all> features (an unusual request!) use C<no feature ':all'>. |
| 116 | | | | | |
| 117 | | | | | =head1 AVAILABLE FEATURES |
| 118 | | | | | |
| 119 | | | | | =head2 The 'say' feature |
| 120 | | | | | |
| 121 | | | | | C<use feature 'say'> tells the compiler to enable the Perl 6 style |
| 122 | | | | | C<say> function. |
| 123 | | | | | |
| 124 | | | | | See L<perlfunc/say> for details. |
| 125 | | | | | |
| 126 | | | | | This feature is available starting with Perl 5.10. |
| 127 | | | | | |
| 128 | | | | | =head2 The 'state' feature |
| 129 | | | | | |
| 130 | | | | | C<use feature 'state'> tells the compiler to enable C<state> |
| 131 | | | | | variables. |
| 132 | | | | | |
| 133 | | | | | See L<perlsub/"Persistent Private Variables"> for details. |
| 134 | | | | | |
| 135 | | | | | This feature is available starting with Perl 5.10. |
| 136 | | | | | |
| 137 | | | | | =head2 The 'switch' feature |
| 138 | | | | | |
| 139 | | | | | B<WARNING>: Because the L<smartmatch operator|perlop/"Smartmatch Operator"> is |
| 140 | | | | | experimental, Perl will warn when you use this feature, unless you have |
| 141 | | | | | explicitly disabled the warning: |
| 142 | | | | | |
| 143 | | | | | no warnings "experimental::smartmatch"; |
| 144 | | | | | |
| 145 | | | | | C<use feature 'switch'> tells the compiler to enable the Perl 6 |
| 146 | | | | | given/when construct. |
| 147 | | | | | |
| 148 | | | | | See L<perlsyn/"Switch Statements"> for details. |
| 149 | | | | | |
| 150 | | | | | This feature is available starting with Perl 5.10. |
| 151 | | | | | |
| 152 | | | | | =head2 The 'unicode_strings' feature |
| 153 | | | | | |
| 154 | | | | | C<use feature 'unicode_strings'> tells the compiler to use Unicode rules |
| 155 | | | | | in all string operations executed within its scope (unless they are also |
| 156 | | | | | within the scope of either C<use locale> or C<use bytes>). The same applies |
| 157 | | | | | to all regular expressions compiled within the scope, even if executed outside |
| 158 | | | | | it. It does not change the internal representation of strings, but only how |
| 159 | | | | | they are interpreted. |
| 160 | | | | | |
| 161 | | | | | C<no feature 'unicode_strings'> tells the compiler to use the traditional |
| 162 | | | | | Perl rules wherein the native character set rules is used unless it is |
| 163 | | | | | clear to Perl that Unicode is desired. This can lead to some surprises |
| 164 | | | | | when the behavior suddenly changes. (See |
| 165 | | | | | L<perlunicode/The "Unicode Bug"> for details.) For this reason, if you are |
| 166 | | | | | potentially using Unicode in your program, the |
| 167 | | | | | C<use feature 'unicode_strings'> subpragma is B<strongly> recommended. |
| 168 | | | | | |
| 169 | | | | | This feature is available starting with Perl 5.12; was almost fully |
| 170 | | | | | implemented in Perl 5.14; and extended in Perl 5.16 to cover C<quotemeta>. |
| 171 | | | | | |
| 172 | | | | | =head2 The 'unicode_eval' and 'evalbytes' features |
| 173 | | | | | |
| 174 | | | | | Under the C<unicode_eval> feature, Perl's C<eval> function, when passed a |
| 175 | | | | | string, will evaluate it as a string of characters, ignoring any |
| 176 | | | | | C<use utf8> declarations. C<use utf8> exists to declare the encoding of |
| 177 | | | | | the script, which only makes sense for a stream of bytes, not a string of |
| 178 | | | | | characters. Source filters are forbidden, as they also really only make |
| 179 | | | | | sense on strings of bytes. Any attempt to activate a source filter will |
| 180 | | | | | result in an error. |
| 181 | | | | | |
| 182 | | | | | The C<evalbytes> feature enables the C<evalbytes> keyword, which evaluates |
| 183 | | | | | the argument passed to it as a string of bytes. It dies if the string |
| 184 | | | | | contains any characters outside the 8-bit range. Source filters work |
| 185 | | | | | within C<evalbytes>: they apply to the contents of the string being |
| 186 | | | | | evaluated. |
| 187 | | | | | |
| 188 | | | | | Together, these two features are intended to replace the historical C<eval> |
| 189 | | | | | function, which has (at least) two bugs in it, that cannot easily be fixed |
| 190 | | | | | without breaking existing programs: |
| 191 | | | | | |
| 192 | | | | | =over |
| 193 | | | | | |
| 194 | | | | | =item * |
| 195 | | | | | |
| 196 | | | | | C<eval> behaves differently depending on the internal encoding of the |
| 197 | | | | | string, sometimes treating its argument as a string of bytes, and sometimes |
| 198 | | | | | as a string of characters. |
| 199 | | | | | |
| 200 | | | | | =item * |
| 201 | | | | | |
| 202 | | | | | Source filters activated within C<eval> leak out into whichever I<file> |
| 203 | | | | | scope is currently being compiled. To give an example with the CPAN module |
| 204 | | | | | L<Semi::Semicolons>: |
| 205 | | | | | |
| 206 | | | | | BEGIN { eval "use Semi::Semicolons; # not filtered here " } |
| 207 | | | | | # filtered here! |
| 208 | | | | | |
| 209 | | | | | C<evalbytes> fixes that to work the way one would expect: |
| 210 | | | | | |
| 211 | | | | | use feature "evalbytes"; |
| 212 | | | | | BEGIN { evalbytes "use Semi::Semicolons; # filtered " } |
| 213 | | | | | # not filtered |
| 214 | | | | | |
| 215 | | | | | =back |
| 216 | | | | | |
| 217 | | | | | These two features are available starting with Perl 5.16. |
| 218 | | | | | |
| 219 | | | | | =head2 The 'current_sub' feature |
| 220 | | | | | |
| 221 | | | | | This provides the C<__SUB__> token that returns a reference to the current |
| 222 | | | | | subroutine or C<undef> outside of a subroutine. |
| 223 | | | | | |
| 224 | | | | | This feature is available starting with Perl 5.16. |
| 225 | | | | | |
| 226 | | | | | =head2 The 'array_base' feature |
| 227 | | | | | |
| 228 | | | | | This feature supports the legacy C<$[> variable. See L<perlvar/$[> and |
| 229 | | | | | L<arybase>. It is on by default but disabled under C<use v5.16> (see |
| 230 | | | | | L</IMPLICIT LOADING>, below). |
| 231 | | | | | |
| 232 | | | | | This feature is available under this name starting with Perl 5.16. In |
| 233 | | | | | previous versions, it was simply on all the time, and this pragma knew |
| 234 | | | | | nothing about it. |
| 235 | | | | | |
| 236 | | | | | =head2 The 'fc' feature |
| 237 | | | | | |
| 238 | | | | | C<use feature 'fc'> tells the compiler to enable the C<fc> function, |
| 239 | | | | | which implements Unicode casefolding. |
| 240 | | | | | |
| 241 | | | | | See L<perlfunc/fc> for details. |
| 242 | | | | | |
| 243 | | | | | This feature is available from Perl 5.16 onwards. |
| 244 | | | | | |
| 245 | | | | | =head2 The 'lexical_subs' feature |
| 246 | | | | | |
| 247 | | | | | B<WARNING>: This feature is still experimental and the implementation may |
| 248 | | | | | change in future versions of Perl. For this reason, Perl will |
| 249 | | | | | warn when you use the feature, unless you have explicitly disabled the |
| 250 | | | | | warning: |
| 251 | | | | | |
| 252 | | | | | no warnings "experimental::lexical_subs"; |
| 253 | | | | | |
| 254 | | | | | This enables declaration of subroutines via C<my sub foo>, C<state sub foo> |
| 255 | | | | | and C<our sub foo> syntax. See L<perlsub/Lexical Subroutines> for details. |
| 256 | | | | | |
| 257 | | | | | This feature is available from Perl 5.18 onwards. |
| 258 | | | | | |
| 259 | | | | | =head2 The 'postderef' and 'postderef_qq' features |
| 260 | | | | | |
| 261 | | | | | B<WARNING>: This feature is still experimental and the implementation may |
| 262 | | | | | change in future versions of Perl. For this reason, Perl will |
| 263 | | | | | warn when you use the feature, unless you have explicitly disabled the |
| 264 | | | | | warning: |
| 265 | | | | | |
| 266 | | | | | no warnings "experimental::postderef"; |
| 267 | | | | | |
| 268 | | | | | The 'postderef' feature allows the use of L<postfix dereference |
| 269 | | | | | syntax|perlref/Postfix Dereference Syntax>. For example, it will make the |
| 270 | | | | | following two statements equivalent: |
| 271 | | | | | |
| 272 | | | | | my @x = @{ $h->{a} }; |
| 273 | | | | | my @x = $h->{a}->@*; |
| 274 | | | | | |
| 275 | | | | | The 'postderef_qq' feature extends this, for array and scalar dereference, to |
| 276 | | | | | working inside of double-quotish interpolations. |
| 277 | | | | | |
| 278 | | | | | This feature is available from Perl 5.20 onwards. |
| 279 | | | | | |
| 280 | | | | | =head2 The 'signatures' feature |
| 281 | | | | | |
| 282 | | | | | B<WARNING>: This feature is still experimental and the implementation may |
| 283 | | | | | change in future versions of Perl. For this reason, Perl will |
| 284 | | | | | warn when you use the feature, unless you have explicitly disabled the |
| 285 | | | | | warning: |
| 286 | | | | | |
| 287 | | | | | no warnings "experimental::signatures"; |
| 288 | | | | | |
| 289 | | | | | This enables unpacking of subroutine arguments into lexical variables |
| 290 | | | | | by syntax such as |
| 291 | | | | | |
| 292 | | | | | sub foo ($left, $right) { |
| 293 | | | | | return $left + $right; |
| 294 | | | | | } |
| 295 | | | | | |
| 296 | | | | | See L<perlsub/Signatures> for details. |
| 297 | | | | | |
| 298 | | | | | This feature is available from Perl 5.20 onwards. |
| 299 | | | | | |
| 300 | | | | | =head2 The 'refaliasing' feature |
| 301 | | | | | |
| 302 | | | | | B<WARNING>: This feature is still experimental and the implementation may |
| 303 | | | | | change in future versions of Perl. For this reason, Perl will |
| 304 | | | | | warn when you use the feature, unless you have explicitly disabled the |
| 305 | | | | | warning: |
| 306 | | | | | |
| 307 | | | | | no warnings "experimental::refaliasing"; |
| 308 | | | | | |
| 309 | | | | | This enables aliasing via assignment to references: |
| 310 | | | | | |
| 311 | | | | | \$a = \$b; # $a and $b now point to the same scalar |
| 312 | | | | | \@a = \@b; # to the same array |
| 313 | | | | | \%a = \%b; |
| 314 | | | | | \&a = \&b; |
| 315 | | | | | foreach \%hash (@array_of_hash_refs) { |
| 316 | | | | | ... |
| 317 | | | | | } |
| 318 | | | | | |
| 319 | | | | | See L<perlref/Assigning to References> for details. |
| 320 | | | | | |
| 321 | | | | | This feature is available from Perl 5.22 onwards. |
| 322 | | | | | |
| 323 | | | | | =head2 The 'bitwise' feature |
| 324 | | | | | |
| 325 | | | | | B<WARNING>: This feature is still experimental and the implementation may |
| 326 | | | | | change in future versions of Perl. For this reason, Perl will |
| 327 | | | | | warn when you use the feature, unless you have explicitly disabled the |
| 328 | | | | | warning: |
| 329 | | | | | |
| 330 | | | | | no warnings "experimental::bitwise"; |
| 331 | | | | | |
| 332 | | | | | This makes the four standard bitwise operators (C<& | ^ ~>) treat their |
| 333 | | | | | operands consistently as numbers, and introduces four new dotted operators |
| 334 | | | | | (C<&. |. ^. ~.>) that treat their operands consistently as strings. The |
| 335 | | | | | same applies to the assignment variants (C<&= |= ^= &.= |.= ^.=>). |
| 336 | | | | | |
| 337 | | | | | See L<perlop/Bitwise String Operators> for details. |
| 338 | | | | | |
| 339 | | | | | This feature is available from Perl 5.22 onwards. |
| 340 | | | | | |
| 341 | | | | | =head1 FEATURE BUNDLES |
| 342 | | | | | |
| 343 | | | | | It's possible to load multiple features together, using |
| 344 | | | | | a I<feature bundle>. The name of a feature bundle is prefixed with |
| 345 | | | | | a colon, to distinguish it from an actual feature. |
| 346 | | | | | |
| 347 | | | | | use feature ":5.10"; |
| 348 | | | | | |
| 349 | | | | | The following feature bundles are available: |
| 350 | | | | | |
| 351 | | | | | bundle features included |
| 352 | | | | | --------- ----------------- |
| 353 | | | | | :default array_base |
| 354 | | | | | |
| 355 | | | | | :5.10 say state switch array_base |
| 356 | | | | | |
| 357 | | | | | :5.12 say state switch unicode_strings array_base |
| 358 | | | | | |
| 359 | | | | | :5.14 say state switch unicode_strings array_base |
| 360 | | | | | |
| 361 | | | | | :5.16 say state switch unicode_strings |
| 362 | | | | | unicode_eval evalbytes current_sub fc |
| 363 | | | | | |
| 364 | | | | | :5.18 say state switch unicode_strings |
| 365 | | | | | unicode_eval evalbytes current_sub fc |
| 366 | | | | | |
| 367 | | | | | :5.20 say state switch unicode_strings |
| 368 | | | | | unicode_eval evalbytes current_sub fc |
| 369 | | | | | |
| 370 | | | | | :5.22 say state switch unicode_strings |
| 371 | | | | | unicode_eval evalbytes current_sub fc |
| 372 | | | | | |
| 373 | | | | | The C<:default> bundle represents the feature set that is enabled before |
| 374 | | | | | any C<use feature> or C<no feature> declaration. |
| 375 | | | | | |
| 376 | | | | | Specifying sub-versions such as the C<0> in C<5.14.0> in feature bundles has |
| 377 | | | | | no effect. Feature bundles are guaranteed to be the same for all sub-versions. |
| 378 | | | | | |
| 379 | | | | | use feature ":5.14.0"; # same as ":5.14" |
| 380 | | | | | use feature ":5.14.1"; # same as ":5.14" |
| 381 | | | | | |
| 382 | | | | | =head1 IMPLICIT LOADING |
| 383 | | | | | |
| 384 | | | | | Instead of loading feature bundles by name, it is easier to let Perl do |
| 385 | | | | | implicit loading of a feature bundle for you. |
| 386 | | | | | |
| 387 | | | | | There are two ways to load the C<feature> pragma implicitly: |
| 388 | | | | | |
| 389 | | | | | =over 4 |
| 390 | | | | | |
| 391 | | | | | =item * |
| 392 | | | | | |
| 393 | | | | | By using the C<-E> switch on the Perl command-line instead of C<-e>. |
| 394 | | | | | That will enable the feature bundle for that version of Perl in the |
| 395 | | | | | main compilation unit (that is, the one-liner that follows C<-E>). |
| 396 | | | | | |
| 397 | | | | | =item * |
| 398 | | | | | |
| 399 | | | | | By explicitly requiring a minimum Perl version number for your program, with |
| 400 | | | | | the C<use VERSION> construct. That is, |
| 401 | | | | | |
| 402 | | | | | use v5.10.0; |
| 403 | | | | | |
| 404 | | | | | will do an implicit |
| 405 | | | | | |
| 406 | | | | | no feature ':all'; |
| 407 | | | | | use feature ':5.10'; |
| 408 | | | | | |
| 409 | | | | | and so on. Note how the trailing sub-version |
| 410 | | | | | is automatically stripped from the |
| 411 | | | | | version. |
| 412 | | | | | |
| 413 | | | | | But to avoid portability warnings (see L<perlfunc/use>), you may prefer: |
| 414 | | | | | |
| 415 | | | | | use 5.010; |
| 416 | | | | | |
| 417 | | | | | with the same effect. |
| 418 | | | | | |
| 419 | | | | | If the required version is older than Perl 5.10, the ":default" feature |
| 420 | | | | | bundle is automatically loaded instead. |
| 421 | | | | | |
| 422 | | | | | =back |
| 423 | | | | | |
| 424 | | | | | =cut |
| 425 | | | | | |
| 426 | | | | | sub import { |
| 427 | | | | | my $class = shift; |
| 428 | | | | | |
| 429 | | | | | if (!@_) { |
| 430 | | | | | croak("No features specified"); |
| 431 | | | | | } |
| 432 | | | | | |
| 433 | | | | | __common(1, @_); |
| 434 | | | | | } |
| 435 | | | | | |
| 436 | | | | | sub unimport { |
| 437 | | | | | my $class = shift; |
| 438 | | | | | |
| 439 | | | | | # A bare C<no feature> should reset to the default bundle |
| 440 | | | | | if (!@_) { |
| 441 | | | | | $^H &= ~($hint_uni8bit|$hint_mask); |
| 442 | | | | | return; |
| 443 | | | | | } |
| 444 | | | | | |
| 445 | | | | | __common(0, @_); |
| 446 | | | | | } |
| 447 | | | | | |
| 448 | | | | | |
| 449 | | | | | sub __common { |
| 450 | | | | | my $import = shift; |
| 451 | | | | | my $bundle_number = $^H & $hint_mask; |
| 452 | | | | | my $features = $bundle_number != $hint_mask |
| 453 | | | | | && $feature_bundle{$hint_bundles[$bundle_number >> $hint_shift]}; |
| 454 | | | | | if ($features) { |
| 455 | | | | | # Features are enabled implicitly via bundle hints. |
| 456 | | | | | # Delete any keys that may be left over from last time. |
| 457 | | | | | delete @^H{ values(%feature) }; |
| 458 | | | | | $^H |= $hint_mask; |
| 459 | | | | | for (@$features) { |
| 460 | | | | | $^H{$feature{$_}} = 1; |
| 461 | | | | | $^H |= $hint_uni8bit if $_ eq 'unicode_strings'; |
| 462 | | | | | } |
| 463 | | | | | } |
| 464 | | | | | while (@_) { |
| 465 | | | | | my $name = shift; |
| 466 | | | | | if (substr($name, 0, 1) eq ":") { |
| 467 | | | | | my $v = substr($name, 1); |
| 468 | | | | | if (!exists $feature_bundle{$v}) { |
| 469 | | | | | $v =~ s/^([0-9]+)\.([0-9]+).[0-9]+$/$1.$2/; |
| 470 | | | | | if (!exists $feature_bundle{$v}) { |
| 471 | | | | | unknown_feature_bundle(substr($name, 1)); |
| 472 | | | | | } |
| 473 | | | | | } |
| 474 | | | | | unshift @_, @{$feature_bundle{$v}}; |
| 475 | | | | | next; |
| 476 | | | | | } |
| 477 | | | | | if (!exists $feature{$name}) { |
| 478 | | | | | unknown_feature($name); |
| 479 | | | | | } |
| 480 | | | | | if ($import) { |
| 481 | | | | | $^H{$feature{$name}} = 1; |
| 482 | | | | | $^H |= $hint_uni8bit if $name eq 'unicode_strings'; |
| 483 | | | | | } else { |
| 484 | | | | | delete $^H{$feature{$name}}; |
| 485 | | | | | $^H &= ~ $hint_uni8bit if $name eq 'unicode_strings'; |
| 486 | | | | | } |
| 487 | | | | | } |
| 488 | | | | | } |
| 489 | | | | | |
| 490 | | | | | sub unknown_feature { |
| 491 | | | | | my $feature = shift; |
| 492 | | | | | croak(sprintf('Feature "%s" is not supported by Perl %vd', |
| 493 | | | | | $feature, $^V)); |
| 494 | | | | | } |
| 495 | | | | | |
| 496 | | | | | sub unknown_feature_bundle { |
| 497 | | | | | my $feature = shift; |
| 498 | | | | | croak(sprintf('Feature bundle "%s" is not supported by Perl %vd', |
| 499 | | | | | $feature, $^V)); |
| 500 | | | | | } |
| 501 | | | | | |
| 502 | | | | | sub croak { |
| 503 | | | | | require Carp; |
| 504 | | | | | Carp::croak(@_); |
| 505 | | | | | } |
| 506 | | | | | |
| 507 | 1 | 19µs | | | 1; |
| 508 | | | | | |
| 509 | | | | | # ex: set ro: |