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69bcf1d3 FC |
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 | ||
0d863452 RH |
6 | package feature; |
7 | ||
fd124146 | 8 | our $VERSION = '1.45'; |
0d863452 | 9 | |
0bb01b05 | 10 | our %feature = ( |
2a4315f8 | 11 | fc => 'feature_fc', |
47e9d84a EB |
12 | say => 'feature_say', |
13 | state => 'feature_state', | |
1863b879 | 14 | switch => 'feature_switch', |
cec892e7 | 15 | bitwise => 'feature_bitwise', |
7d789282 | 16 | evalbytes => 'feature_evalbytes', |
3fff3427 | 17 | array_base => 'feature_arybase', |
30d9c59b | 18 | signatures => 'feature_signatures', |
84ed0108 | 19 | current_sub => 'feature___SUB__', |
baabe3fb | 20 | refaliasing => 'feature_refaliasing', |
158becca | 21 | postderef_qq => 'feature_postderef_qq', |
cda6b701 | 22 | unicode_eval => 'feature_unieval', |
82d83da3 | 23 | declared_refs => 'feature_myref', |
47e9d84a | 24 | unicode_strings => 'feature_unicode', |
bc9b29db RH |
25 | ); |
26 | ||
0d2bd2aa | 27 | our %feature_bundle = ( |
69bcf1d3 FC |
28 | "5.10" => [qw(array_base say state switch)], |
29 | "5.11" => [qw(array_base say state switch unicode_strings)], | |
2a4315f8 | 30 | "5.15" => [qw(current_sub evalbytes fc say state switch unicode_eval unicode_strings)], |
1c2511e0 | 31 | "5.23" => [qw(current_sub evalbytes fc postderef_qq say state switch unicode_eval unicode_strings)], |
82d83da3 | 32 | "all" => [qw(array_base bitwise current_sub declared_refs evalbytes fc postderef_qq refaliasing say signatures state switch unicode_eval unicode_strings)], |
69bcf1d3 | 33 | "default" => [qw(array_base)], |
0d863452 | 34 | ); |
d052521a | 35 | |
88da30d7 FC |
36 | $feature_bundle{"5.12"} = $feature_bundle{"5.11"}; |
37 | $feature_bundle{"5.13"} = $feature_bundle{"5.11"}; | |
38 | $feature_bundle{"5.14"} = $feature_bundle{"5.11"}; | |
39 | $feature_bundle{"5.16"} = $feature_bundle{"5.15"}; | |
d6402ebe | 40 | $feature_bundle{"5.17"} = $feature_bundle{"5.15"}; |
52fc5c56 | 41 | $feature_bundle{"5.18"} = $feature_bundle{"5.15"}; |
d09258e7 RS |
42 | $feature_bundle{"5.19"} = $feature_bundle{"5.15"}; |
43 | $feature_bundle{"5.20"} = $feature_bundle{"5.15"}; | |
b530a4ea RS |
44 | $feature_bundle{"5.21"} = $feature_bundle{"5.15"}; |
45 | $feature_bundle{"5.22"} = $feature_bundle{"5.15"}; | |
2ad792cd | 46 | $feature_bundle{"5.24"} = $feature_bundle{"5.23"}; |
2c5484a6 RS |
47 | $feature_bundle{"5.25"} = $feature_bundle{"5.23"}; |
48 | $feature_bundle{"5.26"} = $feature_bundle{"5.23"}; | |
88da30d7 | 49 | $feature_bundle{"5.9.5"} = $feature_bundle{"5.10"}; |
db629560 FC |
50 | my %noops = ( |
51 | postderef => 1, | |
52 | lexical_subs => 1, | |
53 | ); | |
69bcf1d3 | 54 | |
0bb01b05 FC |
55 | our $hint_shift = 26; |
56 | our $hint_mask = 0x1c000000; | |
2ad792cd | 57 | our @hint_bundles = qw( default 5.10 5.11 5.15 5.23 ); |
ada44f8c | 58 | |
69bcf1d3 FC |
59 | # This gets set (for now) in $^H as well as in %^H, |
60 | # for runtime speed of the uc/lc/ucfirst/lcfirst functions. | |
61 | # See HINT_UNI_8_BIT in perl.h. | |
62 | our $hint_uni8bit = 0x00000800; | |
7dfde25d | 63 | |
0d863452 | 64 | # TODO: |
1c321dc6 | 65 | # - think about versioned features (use feature switch => 2) |
0d863452 RH |
66 | |
67 | =head1 NAME | |
68 | ||
e1b711da | 69 | feature - Perl pragma to enable new features |
0d863452 RH |
70 | |
71 | =head1 SYNOPSIS | |
72 | ||
47e9d84a | 73 | use feature qw(say switch); |
0d863452 | 74 | given ($foo) { |
0b25e784 DG |
75 | when (1) { say "\$foo == 1" } |
76 | when ([2,3]) { say "\$foo == 2 || \$foo == 3" } | |
77 | when (/^a[bc]d$/) { say "\$foo eq 'abd' || \$foo eq 'acd'" } | |
78 | when ($_ > 100) { say "\$foo > 100" } | |
79 | default { say "None of the above" } | |
0d863452 RH |
80 | } |
81 | ||
ec488c7f RGS |
82 | use feature ':5.10'; # loads all features available in perl 5.10 |
83 | ||
0b25e784 DG |
84 | use v5.10; # implicitly loads :5.10 feature bundle |
85 | ||
0d863452 RH |
86 | =head1 DESCRIPTION |
87 | ||
88 | It is usually impossible to add new syntax to Perl without breaking | |
b22bbcf0 | 89 | some existing programs. This pragma provides a way to minimize that |
1863b879 RGS |
90 | risk. New syntactic constructs, or new semantic meanings to older |
91 | constructs, can be enabled by C<use feature 'foo'>, and will be parsed | |
b22bbcf0 | 92 | only when the appropriate feature pragma is in scope. (Nevertheless, the |
4a904372 FC |
93 | C<CORE::> prefix provides access to all Perl keywords, regardless of this |
94 | pragma.) | |
0d863452 | 95 | |
9eb27be9 RGS |
96 | =head2 Lexical effect |
97 | ||
98 | Like other pragmas (C<use strict>, for example), features have a lexical | |
301381dc | 99 | effect. C<use feature qw(foo)> will only make the feature "foo" available |
9eb27be9 RGS |
100 | from that point to the end of the enclosing block. |
101 | ||
102 | { | |
103 | use feature 'say'; | |
104 | say "say is available here"; | |
105 | } | |
106 | print "But not here.\n"; | |
107 | ||
5e36ed56 RGS |
108 | =head2 C<no feature> |
109 | ||
b22bbcf0 | 110 | Features can also be turned off by using C<no feature "foo">. This too |
5e36ed56 RGS |
111 | has lexical effect. |
112 | ||
113 | use feature 'say'; | |
114 | say "say is available here"; | |
115 | { | |
116 | no feature 'say'; | |
117 | print "But not here.\n"; | |
118 | } | |
119 | say "Yet it is here."; | |
120 | ||
39ec54a5 RS |
121 | C<no feature> with no features specified will reset to the default group. To |
122 | disable I<all> features (an unusual request!) use C<no feature ':all'>. | |
5e36ed56 | 123 | |
0b25e784 DG |
124 | =head1 AVAILABLE FEATURES |
125 | ||
0d863452 RH |
126 | =head2 The 'say' feature |
127 | ||
0b25e784 | 128 | C<use feature 'say'> tells the compiler to enable the Perl 6 style |
9eb27be9 | 129 | C<say> function. |
0d863452 RH |
130 | |
131 | See L<perlfunc/say> for details. | |
132 | ||
0b25e784 DG |
133 | This feature is available starting with Perl 5.10. |
134 | ||
135 | =head2 The 'state' feature | |
712d05cf RGS |
136 | |
137 | C<use feature 'state'> tells the compiler to enable C<state> | |
9eb27be9 | 138 | variables. |
712d05cf | 139 | |
e60bcc8b RGS |
140 | See L<perlsub/"Persistent Private Variables"> for details. |
141 | ||
0b25e784 DG |
142 | This feature is available starting with Perl 5.10. |
143 | ||
47e9d84a EB |
144 | =head2 The 'switch' feature |
145 | ||
7caca87c DB |
146 | B<WARNING>: Because the L<smartmatch operator|perlop/"Smartmatch Operator"> is |
147 | experimental, Perl will warn when you use this feature, unless you have | |
148 | explicitly disabled the warning: | |
149 | ||
150 | no warnings "experimental::smartmatch"; | |
151 | ||
47e9d84a EB |
152 | C<use feature 'switch'> tells the compiler to enable the Perl 6 |
153 | given/when construct. | |
154 | ||
48238296 | 155 | See L<perlsyn/"Switch Statements"> for details. |
47e9d84a | 156 | |
0b25e784 DG |
157 | This feature is available starting with Perl 5.10. |
158 | ||
159 | =head2 The 'unicode_strings' feature | |
1863b879 | 160 | |
850b7ec9 | 161 | C<use feature 'unicode_strings'> tells the compiler to use Unicode rules |
20db7501 KW |
162 | in all string operations executed within its scope (unless they are also |
163 | within the scope of either C<use locale> or C<use bytes>). The same applies | |
164 | to all regular expressions compiled within the scope, even if executed outside | |
2269d15c KW |
165 | it. It does not change the internal representation of strings, but only how |
166 | they are interpreted. | |
20db7501 KW |
167 | |
168 | C<no feature 'unicode_strings'> tells the compiler to use the traditional | |
850b7ec9 | 169 | Perl rules wherein the native character set rules is used unless it is |
20db7501 KW |
170 | clear to Perl that Unicode is desired. This can lead to some surprises |
171 | when the behavior suddenly changes. (See | |
172 | L<perlunicode/The "Unicode Bug"> for details.) For this reason, if you are | |
173 | potentially using Unicode in your program, the | |
174 | C<use feature 'unicode_strings'> subpragma is B<strongly> recommended. | |
175 | ||
2e2b2571 KW |
176 | This feature is available starting with Perl 5.12; was almost fully |
177 | implemented in Perl 5.14; and extended in Perl 5.16 to cover C<quotemeta>. | |
1863b879 | 178 | |
0b25e784 | 179 | =head2 The 'unicode_eval' and 'evalbytes' features |
7289c5e6 FC |
180 | |
181 | Under the C<unicode_eval> feature, Perl's C<eval> function, when passed a | |
182 | string, will evaluate it as a string of characters, ignoring any | |
183 | C<use utf8> declarations. C<use utf8> exists to declare the encoding of | |
184 | the script, which only makes sense for a stream of bytes, not a string of | |
185 | characters. Source filters are forbidden, as they also really only make | |
186 | sense on strings of bytes. Any attempt to activate a source filter will | |
187 | result in an error. | |
188 | ||
189 | The C<evalbytes> feature enables the C<evalbytes> keyword, which evaluates | |
190 | the argument passed to it as a string of bytes. It dies if the string | |
191 | contains any characters outside the 8-bit range. Source filters work | |
192 | within C<evalbytes>: they apply to the contents of the string being | |
193 | evaluated. | |
194 | ||
195 | Together, these two features are intended to replace the historical C<eval> | |
196 | function, which has (at least) two bugs in it, that cannot easily be fixed | |
197 | without breaking existing programs: | |
198 | ||
199 | =over | |
200 | ||
201 | =item * | |
202 | ||
203 | C<eval> behaves differently depending on the internal encoding of the | |
204 | string, sometimes treating its argument as a string of bytes, and sometimes | |
205 | as a string of characters. | |
206 | ||
207 | =item * | |
208 | ||
209 | Source filters activated within C<eval> leak out into whichever I<file> | |
210 | scope is currently being compiled. To give an example with the CPAN module | |
211 | L<Semi::Semicolons>: | |
212 | ||
213 | BEGIN { eval "use Semi::Semicolons; # not filtered here " } | |
214 | # filtered here! | |
215 | ||
216 | C<evalbytes> fixes that to work the way one would expect: | |
217 | ||
218 | use feature "evalbytes"; | |
219 | BEGIN { evalbytes "use Semi::Semicolons; # filtered " } | |
220 | # not filtered | |
221 | ||
222 | =back | |
223 | ||
224 | These two features are available starting with Perl 5.16. | |
225 | ||
84ed0108 FC |
226 | =head2 The 'current_sub' feature |
227 | ||
228 | This provides the C<__SUB__> token that returns a reference to the current | |
229 | subroutine or C<undef> outside of a subroutine. | |
230 | ||
231 | This feature is available starting with Perl 5.16. | |
232 | ||
01868d00 FC |
233 | =head2 The 'array_base' feature |
234 | ||
235 | This feature supports the legacy C<$[> variable. See L<perlvar/$[> and | |
236 | L<arybase>. It is on by default but disabled under C<use v5.16> (see | |
237 | L</IMPLICIT LOADING>, below). | |
238 | ||
239 | This feature is available under this name starting with Perl 5.16. In | |
240 | previous versions, it was simply on all the time, and this pragma knew | |
241 | nothing about it. | |
242 | ||
2a4315f8 BF |
243 | =head2 The 'fc' feature |
244 | ||
245 | C<use feature 'fc'> tells the compiler to enable the C<fc> function, | |
246 | which implements Unicode casefolding. | |
247 | ||
248 | See L<perlfunc/fc> for details. | |
249 | ||
250 | This feature is available from Perl 5.16 onwards. | |
251 | ||
ca40957e FC |
252 | =head2 The 'lexical_subs' feature |
253 | ||
8f7d85af FC |
254 | In Perl versions prior to 5.26, this feature enabled |
255 | declaration of subroutines via C<my sub foo>, C<state sub foo> | |
256 | and C<our sub foo> syntax. See L<perlsub/Lexical Subroutines> for details. | |
ca40957e | 257 | |
8f7d85af FC |
258 | This feature is available from Perl 5.18 onwards. From Perl 5.18 to 5.24, |
259 | it was classed as experimental, and Perl emitted a warning for its | |
260 | usage, except when explicitly disabled: | |
ca40957e | 261 | |
8f7d85af | 262 | no warnings "experimental::lexical_subs"; |
ca40957e | 263 | |
8f7d85af FC |
264 | As of Perl 5.26, use of this feature no longer triggers a warning, though |
265 | the C<experimental::lexical_subs> warning category still exists (for | |
266 | compatibility with code that disables it). In addition, this syntax is | |
267 | not only no longer experimental, but it is enabled for all Perl code, | |
268 | regardless of what feature declarations are in scope. | |
ca40957e | 269 | |
f86d720e RS |
270 | =head2 The 'postderef' and 'postderef_qq' features |
271 | ||
1c2511e0 AC |
272 | The 'postderef_qq' feature extends the applicability of L<postfix |
273 | dereference syntax|perlref/Postfix Dereference Syntax> so that postfix array | |
274 | and scalar dereference are available in double-quotish interpolations. For | |
275 | example, it makes the following two statements equivalent: | |
f86d720e | 276 | |
1c2511e0 AC |
277 | my $s = "[@{ $h->{a} }]"; |
278 | my $s = "[$h->{a}->@*]"; | |
f86d720e | 279 | |
1c2511e0 AC |
280 | This feature is available from Perl 5.20 onwards. In Perl 5.20 and 5.22, it |
281 | was classed as experimental, and Perl emitted a warning for its | |
2ad792cd AC |
282 | usage, except when explicitly disabled: |
283 | ||
284 | no warnings "experimental::postderef"; | |
285 | ||
1c2511e0 | 286 | As of Perl 5.24, use of this feature no longer triggers a warning, though |
2ad792cd AC |
287 | the C<experimental::postderef> warning category still exists (for |
288 | compatibility with code that disables it). | |
f86d720e | 289 | |
1c2511e0 AC |
290 | The 'postderef' feature was used in Perl 5.20 and Perl 5.22 to enable |
291 | postfix dereference syntax outside double-quotish interpolations. In those | |
292 | versions, using it triggered the C<experimental::postderef> warning in the | |
293 | same way as the 'postderef_qq' feature did. As of Perl 5.24, this syntax is | |
294 | not only no longer experimental, but it is enabled for all Perl code, | |
295 | regardless of what feature declarations are in scope. | |
296 | ||
30d9c59b Z |
297 | =head2 The 'signatures' feature |
298 | ||
299 | B<WARNING>: This feature is still experimental and the implementation may | |
300 | change in future versions of Perl. For this reason, Perl will | |
301 | warn when you use the feature, unless you have explicitly disabled the | |
302 | warning: | |
303 | ||
304 | no warnings "experimental::signatures"; | |
305 | ||
306 | This enables unpacking of subroutine arguments into lexical variables | |
307 | by syntax such as | |
308 | ||
309 | sub foo ($left, $right) { | |
310 | return $left + $right; | |
311 | } | |
312 | ||
313 | See L<perlsub/Signatures> for details. | |
314 | ||
315 | This feature is available from Perl 5.20 onwards. | |
316 | ||
baabe3fb | 317 | =head2 The 'refaliasing' feature |
82848c10 FC |
318 | |
319 | B<WARNING>: This feature is still experimental and the implementation may | |
320 | change in future versions of Perl. For this reason, Perl will | |
321 | warn when you use the feature, unless you have explicitly disabled the | |
322 | warning: | |
323 | ||
baabe3fb | 324 | no warnings "experimental::refaliasing"; |
82848c10 FC |
325 | |
326 | This enables aliasing via assignment to references: | |
327 | ||
328 | \$a = \$b; # $a and $b now point to the same scalar | |
329 | \@a = \@b; # to the same array | |
330 | \%a = \%b; | |
331 | \&a = \&b; | |
332 | foreach \%hash (@array_of_hash_refs) { | |
333 | ... | |
334 | } | |
335 | ||
336 | See L<perlref/Assigning to References> for details. | |
337 | ||
338 | This feature is available from Perl 5.22 onwards. | |
339 | ||
70ea8edf FC |
340 | =head2 The 'bitwise' feature |
341 | ||
342 | B<WARNING>: This feature is still experimental and the implementation may | |
343 | change in future versions of Perl. For this reason, Perl will | |
344 | warn when you use the feature, unless you have explicitly disabled the | |
345 | warning: | |
346 | ||
347 | no warnings "experimental::bitwise"; | |
348 | ||
349 | This makes the four standard bitwise operators (C<& | ^ ~>) treat their | |
350 | operands consistently as numbers, and introduces four new dotted operators | |
351 | (C<&. |. ^. ~.>) that treat their operands consistently as strings. The | |
352 | same applies to the assignment variants (C<&= |= ^= &.= |.= ^.=>). | |
353 | ||
354 | See L<perlop/Bitwise String Operators> for details. | |
355 | ||
356 | This feature is available from Perl 5.22 onwards. | |
357 | ||
5c703779 FC |
358 | =head2 The 'declared_refs' feature |
359 | ||
360 | B<WARNING>: This feature is still experimental and the implementation may | |
361 | change in future versions of Perl. For this reason, Perl will | |
362 | warn when you use the feature, unless you have explicitly disabled the | |
363 | warning: | |
364 | ||
365 | no warnings "experimental::declared_refs"; | |
366 | ||
367 | This allows a reference to a variable to be declared with C<my>, C<state>, | |
368 | our C<our>, or localized with C<local>. It is intended mainly for use in | |
369 | conjunction with the "refaliasing" feature. See L<perlref/Declaring a | |
370 | Reference to a Variable> for examples. | |
371 | ||
372 | This feature is available from Perl 5.26 onwards. | |
373 | ||
bc9b29db RH |
374 | =head1 FEATURE BUNDLES |
375 | ||
0b25e784 | 376 | It's possible to load multiple features together, using |
b22bbcf0 | 377 | a I<feature bundle>. The name of a feature bundle is prefixed with |
0b25e784 DG |
378 | a colon, to distinguish it from an actual feature. |
379 | ||
380 | use feature ":5.10"; | |
381 | ||
382 | The following feature bundles are available: | |
383 | ||
384 | bundle features included | |
385 | --------- ----------------- | |
01868d00 | 386 | :default array_base |
0b25e784 | 387 | |
01868d00 | 388 | :5.10 say state switch array_base |
0b25e784 | 389 | |
01868d00 | 390 | :5.12 say state switch unicode_strings array_base |
0b25e784 | 391 | |
01868d00 | 392 | :5.14 say state switch unicode_strings array_base |
0b25e784 DG |
393 | |
394 | :5.16 say state switch unicode_strings | |
2a4315f8 | 395 | unicode_eval evalbytes current_sub fc |
0b25e784 | 396 | |
52fc5c56 FC |
397 | :5.18 say state switch unicode_strings |
398 | unicode_eval evalbytes current_sub fc | |
399 | ||
d09258e7 RS |
400 | :5.20 say state switch unicode_strings |
401 | unicode_eval evalbytes current_sub fc | |
402 | ||
b530a4ea RS |
403 | :5.22 say state switch unicode_strings |
404 | unicode_eval evalbytes current_sub fc | |
405 | ||
6031f0d2 RS |
406 | :5.24 say state switch unicode_strings |
407 | unicode_eval evalbytes current_sub fc | |
1c2511e0 | 408 | postderef_qq |
6031f0d2 | 409 | |
2c5484a6 RS |
410 | :5.26 say state switch unicode_strings |
411 | unicode_eval evalbytes current_sub fc | |
412 | postderef_qq | |
413 | ||
01868d00 FC |
414 | The C<:default> bundle represents the feature set that is enabled before |
415 | any C<use feature> or C<no feature> declaration. | |
a3a91442 JV |
416 | |
417 | Specifying sub-versions such as the C<0> in C<5.14.0> in feature bundles has | |
b22bbcf0 | 418 | no effect. Feature bundles are guaranteed to be the same for all sub-versions. |
bc9b29db | 419 | |
0b25e784 DG |
420 | use feature ":5.14.0"; # same as ":5.14" |
421 | use feature ":5.14.1"; # same as ":5.14" | |
a3a91442 | 422 | |
7dfde25d RGS |
423 | =head1 IMPLICIT LOADING |
424 | ||
0b25e784 DG |
425 | Instead of loading feature bundles by name, it is easier to let Perl do |
426 | implicit loading of a feature bundle for you. | |
427 | ||
428 | There are two ways to load the C<feature> pragma implicitly: | |
7dfde25d RGS |
429 | |
430 | =over 4 | |
431 | ||
432 | =item * | |
433 | ||
0b25e784 DG |
434 | By using the C<-E> switch on the Perl command-line instead of C<-e>. |
435 | That will enable the feature bundle for that version of Perl in the | |
436 | main compilation unit (that is, the one-liner that follows C<-E>). | |
7dfde25d RGS |
437 | |
438 | =item * | |
439 | ||
0b25e784 | 440 | By explicitly requiring a minimum Perl version number for your program, with |
b22bbcf0 | 441 | the C<use VERSION> construct. That is, |
7dfde25d | 442 | |
0b25e784 | 443 | use v5.10.0; |
7dfde25d RGS |
444 | |
445 | will do an implicit | |
446 | ||
39ec54a5 | 447 | no feature ':all'; |
82cfb3a2 | 448 | use feature ':5.10'; |
7dfde25d | 449 | |
b22bbcf0 FC |
450 | and so on. Note how the trailing sub-version |
451 | is automatically stripped from the | |
82cfb3a2 | 452 | version. |
7dfde25d | 453 | |
8d115822 RB |
454 | But to avoid portability warnings (see L<perlfunc/use>), you may prefer: |
455 | ||
456 | use 5.010; | |
457 | ||
458 | with the same effect. | |
459 | ||
0b25e784 | 460 | If the required version is older than Perl 5.10, the ":default" feature |
01868d00 | 461 | bundle is automatically loaded instead. |
70397346 | 462 | |
7dfde25d RGS |
463 | =back |
464 | ||
0d863452 RH |
465 | =cut |
466 | ||
467 | sub import { | |
22055af9 | 468 | shift; |
36143a0c NC |
469 | |
470 | if (!@_) { | |
0b25e784 | 471 | croak("No features specified"); |
0d863452 | 472 | } |
36143a0c | 473 | |
d3757264 | 474 | __common(1, @_); |
0d863452 RH |
475 | } |
476 | ||
477 | sub unimport { | |
22055af9 | 478 | shift; |
0d863452 | 479 | |
39ec54a5 | 480 | # A bare C<no feature> should reset to the default bundle |
bc9b29db | 481 | if (!@_) { |
39ec54a5 RS |
482 | $^H &= ~($hint_uni8bit|$hint_mask); |
483 | return; | |
bc9b29db RH |
484 | } |
485 | ||
d3757264 NC |
486 | __common(0, @_); |
487 | } | |
488 | ||
489 | ||
490 | sub __common { | |
491 | my $import = shift; | |
0c8d5017 NC |
492 | my $bundle_number = $^H & $hint_mask; |
493 | my $features = $bundle_number != $hint_mask | |
494 | && $feature_bundle{$hint_bundles[$bundle_number >> $hint_shift]}; | |
495 | if ($features) { | |
da5b5421 | 496 | # Features are enabled implicitly via bundle hints. |
d9ee6ccb NC |
497 | # Delete any keys that may be left over from last time. |
498 | delete @^H{ values(%feature) }; | |
499 | $^H |= $hint_mask; | |
500 | for (@$features) { | |
501 | $^H{$feature{$_}} = 1; | |
502 | $^H |= $hint_uni8bit if $_ eq 'unicode_strings'; | |
503 | } | |
da5b5421 | 504 | } |
bc9b29db | 505 | while (@_) { |
0b25e784 DG |
506 | my $name = shift; |
507 | if (substr($name, 0, 1) eq ":") { | |
508 | my $v = substr($name, 1); | |
509 | if (!exists $feature_bundle{$v}) { | |
510 | $v =~ s/^([0-9]+)\.([0-9]+).[0-9]+$/$1.$2/; | |
511 | if (!exists $feature_bundle{$v}) { | |
512 | unknown_feature_bundle(substr($name, 1)); | |
513 | } | |
514 | } | |
515 | unshift @_, @{$feature_bundle{$v}}; | |
516 | next; | |
517 | } | |
36143a0c | 518 | if (!exists $feature{$name}) { |
db629560 FC |
519 | if (exists $noops{$name}) { |
520 | next; | |
521 | } | |
0b25e784 DG |
522 | unknown_feature($name); |
523 | } | |
d3757264 NC |
524 | if ($import) { |
525 | $^H{$feature{$name}} = 1; | |
526 | $^H |= $hint_uni8bit if $name eq 'unicode_strings'; | |
527 | } else { | |
0b25e784 | 528 | delete $^H{$feature{$name}}; |
1863b879 | 529 | $^H &= ~ $hint_uni8bit if $name eq 'unicode_strings'; |
0b25e784 | 530 | } |
0d863452 | 531 | } |
0d863452 RH |
532 | } |
533 | ||
b42943c4 RGS |
534 | sub unknown_feature { |
535 | my $feature = shift; | |
536 | croak(sprintf('Feature "%s" is not supported by Perl %vd', | |
0b25e784 | 537 | $feature, $^V)); |
b42943c4 RGS |
538 | } |
539 | ||
540 | sub unknown_feature_bundle { | |
541 | my $feature = shift; | |
542 | croak(sprintf('Feature bundle "%s" is not supported by Perl %vd', | |
0b25e784 | 543 | $feature, $^V)); |
b42943c4 RGS |
544 | } |
545 | ||
546 | sub croak { | |
547 | require Carp; | |
548 | Carp::croak(@_); | |
549 | } | |
550 | ||
0d863452 | 551 | 1; |
69bcf1d3 FC |
552 | |
553 | # ex: set ro: |