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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 | ||
affe54fa | 8 | our $VERSION = '1.52'; |
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)], |
401d2aaa | 32 | "5.27" => [qw(bitwise current_sub evalbytes fc postderef_qq say state switch unicode_eval unicode_strings)], |
82d83da3 | 33 | "all" => [qw(array_base bitwise current_sub declared_refs evalbytes fc postderef_qq refaliasing say signatures state switch unicode_eval unicode_strings)], |
69bcf1d3 | 34 | "default" => [qw(array_base)], |
0d863452 | 35 | ); |
d052521a | 36 | |
88da30d7 FC |
37 | $feature_bundle{"5.12"} = $feature_bundle{"5.11"}; |
38 | $feature_bundle{"5.13"} = $feature_bundle{"5.11"}; | |
39 | $feature_bundle{"5.14"} = $feature_bundle{"5.11"}; | |
40 | $feature_bundle{"5.16"} = $feature_bundle{"5.15"}; | |
d6402ebe | 41 | $feature_bundle{"5.17"} = $feature_bundle{"5.15"}; |
52fc5c56 | 42 | $feature_bundle{"5.18"} = $feature_bundle{"5.15"}; |
d09258e7 RS |
43 | $feature_bundle{"5.19"} = $feature_bundle{"5.15"}; |
44 | $feature_bundle{"5.20"} = $feature_bundle{"5.15"}; | |
b530a4ea RS |
45 | $feature_bundle{"5.21"} = $feature_bundle{"5.15"}; |
46 | $feature_bundle{"5.22"} = $feature_bundle{"5.15"}; | |
2ad792cd | 47 | $feature_bundle{"5.24"} = $feature_bundle{"5.23"}; |
2c5484a6 RS |
48 | $feature_bundle{"5.25"} = $feature_bundle{"5.23"}; |
49 | $feature_bundle{"5.26"} = $feature_bundle{"5.23"}; | |
401d2aaa | 50 | $feature_bundle{"5.28"} = $feature_bundle{"5.27"}; |
88da30d7 | 51 | $feature_bundle{"5.9.5"} = $feature_bundle{"5.10"}; |
db629560 FC |
52 | my %noops = ( |
53 | postderef => 1, | |
54 | lexical_subs => 1, | |
55 | ); | |
69bcf1d3 | 56 | |
0bb01b05 FC |
57 | our $hint_shift = 26; |
58 | our $hint_mask = 0x1c000000; | |
401d2aaa | 59 | our @hint_bundles = qw( default 5.10 5.11 5.15 5.23 5.27 ); |
ada44f8c | 60 | |
69bcf1d3 FC |
61 | # This gets set (for now) in $^H as well as in %^H, |
62 | # for runtime speed of the uc/lc/ucfirst/lcfirst functions. | |
63 | # See HINT_UNI_8_BIT in perl.h. | |
64 | our $hint_uni8bit = 0x00000800; | |
7dfde25d | 65 | |
0d863452 | 66 | # TODO: |
1c321dc6 | 67 | # - think about versioned features (use feature switch => 2) |
0d863452 RH |
68 | |
69 | =head1 NAME | |
70 | ||
e1b711da | 71 | feature - Perl pragma to enable new features |
0d863452 RH |
72 | |
73 | =head1 SYNOPSIS | |
74 | ||
47e9d84a | 75 | use feature qw(say switch); |
0d863452 | 76 | given ($foo) { |
0b25e784 DG |
77 | when (1) { say "\$foo == 1" } |
78 | when ([2,3]) { say "\$foo == 2 || \$foo == 3" } | |
79 | when (/^a[bc]d$/) { say "\$foo eq 'abd' || \$foo eq 'acd'" } | |
80 | when ($_ > 100) { say "\$foo > 100" } | |
81 | default { say "None of the above" } | |
0d863452 RH |
82 | } |
83 | ||
ec488c7f RGS |
84 | use feature ':5.10'; # loads all features available in perl 5.10 |
85 | ||
0b25e784 DG |
86 | use v5.10; # implicitly loads :5.10 feature bundle |
87 | ||
0d863452 RH |
88 | =head1 DESCRIPTION |
89 | ||
90 | It is usually impossible to add new syntax to Perl without breaking | |
b22bbcf0 | 91 | some existing programs. This pragma provides a way to minimize that |
1863b879 RGS |
92 | risk. New syntactic constructs, or new semantic meanings to older |
93 | constructs, can be enabled by C<use feature 'foo'>, and will be parsed | |
b22bbcf0 | 94 | only when the appropriate feature pragma is in scope. (Nevertheless, the |
4a904372 FC |
95 | C<CORE::> prefix provides access to all Perl keywords, regardless of this |
96 | pragma.) | |
0d863452 | 97 | |
9eb27be9 RGS |
98 | =head2 Lexical effect |
99 | ||
100 | Like other pragmas (C<use strict>, for example), features have a lexical | |
301381dc | 101 | effect. C<use feature qw(foo)> will only make the feature "foo" available |
9eb27be9 RGS |
102 | from that point to the end of the enclosing block. |
103 | ||
104 | { | |
105 | use feature 'say'; | |
106 | say "say is available here"; | |
107 | } | |
108 | print "But not here.\n"; | |
109 | ||
5e36ed56 RGS |
110 | =head2 C<no feature> |
111 | ||
b22bbcf0 | 112 | Features can also be turned off by using C<no feature "foo">. This too |
5e36ed56 RGS |
113 | has lexical effect. |
114 | ||
115 | use feature 'say'; | |
116 | say "say is available here"; | |
117 | { | |
118 | no feature 'say'; | |
119 | print "But not here.\n"; | |
120 | } | |
121 | say "Yet it is here."; | |
122 | ||
39ec54a5 RS |
123 | C<no feature> with no features specified will reset to the default group. To |
124 | disable I<all> features (an unusual request!) use C<no feature ':all'>. | |
5e36ed56 | 125 | |
0b25e784 DG |
126 | =head1 AVAILABLE FEATURES |
127 | ||
0d863452 RH |
128 | =head2 The 'say' feature |
129 | ||
0b25e784 | 130 | C<use feature 'say'> tells the compiler to enable the Perl 6 style |
9eb27be9 | 131 | C<say> function. |
0d863452 RH |
132 | |
133 | See L<perlfunc/say> for details. | |
134 | ||
0b25e784 DG |
135 | This feature is available starting with Perl 5.10. |
136 | ||
137 | =head2 The 'state' feature | |
712d05cf RGS |
138 | |
139 | C<use feature 'state'> tells the compiler to enable C<state> | |
9eb27be9 | 140 | variables. |
712d05cf | 141 | |
e60bcc8b RGS |
142 | See L<perlsub/"Persistent Private Variables"> for details. |
143 | ||
0b25e784 DG |
144 | This feature is available starting with Perl 5.10. |
145 | ||
47e9d84a EB |
146 | =head2 The 'switch' feature |
147 | ||
7caca87c DB |
148 | B<WARNING>: Because the L<smartmatch operator|perlop/"Smartmatch Operator"> is |
149 | experimental, Perl will warn when you use this feature, unless you have | |
150 | explicitly disabled the warning: | |
151 | ||
152 | no warnings "experimental::smartmatch"; | |
153 | ||
7896dde7 | 154 | C<use feature 'switch'> tells the compiler to enable the Perl 6 |
47e9d84a EB |
155 | given/when construct. |
156 | ||
48238296 | 157 | See L<perlsyn/"Switch Statements"> for details. |
47e9d84a | 158 | |
0b25e784 DG |
159 | This feature is available starting with Perl 5.10. |
160 | ||
161 | =head2 The 'unicode_strings' feature | |
1863b879 | 162 | |
850b7ec9 | 163 | C<use feature 'unicode_strings'> tells the compiler to use Unicode rules |
20db7501 KW |
164 | in all string operations executed within its scope (unless they are also |
165 | within the scope of either C<use locale> or C<use bytes>). The same applies | |
166 | to all regular expressions compiled within the scope, even if executed outside | |
2269d15c KW |
167 | it. It does not change the internal representation of strings, but only how |
168 | they are interpreted. | |
20db7501 KW |
169 | |
170 | C<no feature 'unicode_strings'> tells the compiler to use the traditional | |
850b7ec9 | 171 | Perl rules wherein the native character set rules is used unless it is |
20db7501 KW |
172 | clear to Perl that Unicode is desired. This can lead to some surprises |
173 | when the behavior suddenly changes. (See | |
174 | L<perlunicode/The "Unicode Bug"> for details.) For this reason, if you are | |
175 | potentially using Unicode in your program, the | |
176 | C<use feature 'unicode_strings'> subpragma is B<strongly> recommended. | |
177 | ||
2e2b2571 | 178 | This feature is available starting with Perl 5.12; was almost fully |
d6c970c7 | 179 | implemented in Perl 5.14; and extended in Perl 5.16 to cover C<quotemeta>; |
20ae58f7 AC |
180 | was extended further in Perl 5.26 to cover L<the range |
181 | operator|perlop/Range Operators>; and was extended again in Perl 5.28 to | |
182 | cover L<special-cased whitespace splitting|perlfunc/split>. | |
1863b879 | 183 | |
0b25e784 | 184 | =head2 The 'unicode_eval' and 'evalbytes' features |
7289c5e6 | 185 | |
9891e9b7 KW |
186 | Together, these two features are intended to replace the legacy string |
187 | C<eval> function, which behaves problematically in some instances. They are | |
188 | available starting with Perl 5.16, and are enabled by default by a | |
189 | S<C<use 5.16>> or higher declaration. | |
190 | ||
191 | C<unicode_eval> changes the behavior of plain string C<eval> to work more | |
192 | consistently, especially in the Unicode world. Certain (mis)behaviors | |
193 | couldn't be changed without breaking some things that had come to rely on | |
194 | them, so the feature can be enabled and disabled. Details are at | |
195 | L<perlfunc/Under the "unicode_eval" feature>. | |
196 | ||
197 | C<evalbytes> is like string C<eval>, but operating on a byte stream that is | |
198 | not UTF-8 encoded. Details are at L<perlfunc/evalbytes EXPR>. Without a | |
199 | S<C<use feature 'evalbytes'>> nor a S<C<use v5.16>> (or higher) declaration in | |
200 | the current scope, you can still access it by instead writing | |
201 | C<CORE::evalbytes>. | |
7289c5e6 | 202 | |
84ed0108 FC |
203 | =head2 The 'current_sub' feature |
204 | ||
205 | This provides the C<__SUB__> token that returns a reference to the current | |
206 | subroutine or C<undef> outside of a subroutine. | |
207 | ||
208 | This feature is available starting with Perl 5.16. | |
209 | ||
01868d00 FC |
210 | =head2 The 'array_base' feature |
211 | ||
212 | This feature supports the legacy C<$[> variable. See L<perlvar/$[> and | |
213 | L<arybase>. It is on by default but disabled under C<use v5.16> (see | |
214 | L</IMPLICIT LOADING>, below). | |
215 | ||
216 | This feature is available under this name starting with Perl 5.16. In | |
217 | previous versions, it was simply on all the time, and this pragma knew | |
218 | nothing about it. | |
219 | ||
2a4315f8 BF |
220 | =head2 The 'fc' feature |
221 | ||
222 | C<use feature 'fc'> tells the compiler to enable the C<fc> function, | |
223 | which implements Unicode casefolding. | |
224 | ||
225 | See L<perlfunc/fc> for details. | |
226 | ||
227 | This feature is available from Perl 5.16 onwards. | |
228 | ||
ca40957e FC |
229 | =head2 The 'lexical_subs' feature |
230 | ||
8f7d85af FC |
231 | In Perl versions prior to 5.26, this feature enabled |
232 | declaration of subroutines via C<my sub foo>, C<state sub foo> | |
233 | and C<our sub foo> syntax. See L<perlsub/Lexical Subroutines> for details. | |
ca40957e | 234 | |
8f7d85af FC |
235 | This feature is available from Perl 5.18 onwards. From Perl 5.18 to 5.24, |
236 | it was classed as experimental, and Perl emitted a warning for its | |
237 | usage, except when explicitly disabled: | |
ca40957e | 238 | |
8f7d85af | 239 | no warnings "experimental::lexical_subs"; |
ca40957e | 240 | |
8f7d85af FC |
241 | As of Perl 5.26, use of this feature no longer triggers a warning, though |
242 | the C<experimental::lexical_subs> warning category still exists (for | |
243 | compatibility with code that disables it). In addition, this syntax is | |
244 | not only no longer experimental, but it is enabled for all Perl code, | |
245 | regardless of what feature declarations are in scope. | |
ca40957e | 246 | |
f86d720e RS |
247 | =head2 The 'postderef' and 'postderef_qq' features |
248 | ||
1c2511e0 AC |
249 | The 'postderef_qq' feature extends the applicability of L<postfix |
250 | dereference syntax|perlref/Postfix Dereference Syntax> so that postfix array | |
251 | and scalar dereference are available in double-quotish interpolations. For | |
252 | example, it makes the following two statements equivalent: | |
f86d720e | 253 | |
1c2511e0 AC |
254 | my $s = "[@{ $h->{a} }]"; |
255 | my $s = "[$h->{a}->@*]"; | |
f86d720e | 256 | |
1c2511e0 AC |
257 | This feature is available from Perl 5.20 onwards. In Perl 5.20 and 5.22, it |
258 | was classed as experimental, and Perl emitted a warning for its | |
2ad792cd AC |
259 | usage, except when explicitly disabled: |
260 | ||
261 | no warnings "experimental::postderef"; | |
262 | ||
1c2511e0 | 263 | As of Perl 5.24, use of this feature no longer triggers a warning, though |
2ad792cd AC |
264 | the C<experimental::postderef> warning category still exists (for |
265 | compatibility with code that disables it). | |
f86d720e | 266 | |
1c2511e0 AC |
267 | The 'postderef' feature was used in Perl 5.20 and Perl 5.22 to enable |
268 | postfix dereference syntax outside double-quotish interpolations. In those | |
269 | versions, using it triggered the C<experimental::postderef> warning in the | |
270 | same way as the 'postderef_qq' feature did. As of Perl 5.24, this syntax is | |
271 | not only no longer experimental, but it is enabled for all Perl code, | |
272 | regardless of what feature declarations are in scope. | |
273 | ||
30d9c59b Z |
274 | =head2 The 'signatures' feature |
275 | ||
276 | B<WARNING>: This feature is still experimental and the implementation may | |
277 | change in future versions of Perl. For this reason, Perl will | |
278 | warn when you use the feature, unless you have explicitly disabled the | |
279 | warning: | |
280 | ||
281 | no warnings "experimental::signatures"; | |
282 | ||
283 | This enables unpacking of subroutine arguments into lexical variables | |
284 | by syntax such as | |
285 | ||
286 | sub foo ($left, $right) { | |
287 | return $left + $right; | |
288 | } | |
289 | ||
290 | See L<perlsub/Signatures> for details. | |
291 | ||
292 | This feature is available from Perl 5.20 onwards. | |
293 | ||
baabe3fb | 294 | =head2 The 'refaliasing' feature |
82848c10 FC |
295 | |
296 | B<WARNING>: This feature is still experimental and the implementation may | |
297 | change in future versions of Perl. For this reason, Perl will | |
298 | warn when you use the feature, unless you have explicitly disabled the | |
299 | warning: | |
300 | ||
baabe3fb | 301 | no warnings "experimental::refaliasing"; |
82848c10 FC |
302 | |
303 | This enables aliasing via assignment to references: | |
304 | ||
305 | \$a = \$b; # $a and $b now point to the same scalar | |
306 | \@a = \@b; # to the same array | |
307 | \%a = \%b; | |
308 | \&a = \&b; | |
309 | foreach \%hash (@array_of_hash_refs) { | |
310 | ... | |
311 | } | |
312 | ||
313 | See L<perlref/Assigning to References> for details. | |
314 | ||
315 | This feature is available from Perl 5.22 onwards. | |
316 | ||
70ea8edf FC |
317 | =head2 The 'bitwise' feature |
318 | ||
70ea8edf FC |
319 | This makes the four standard bitwise operators (C<& | ^ ~>) treat their |
320 | operands consistently as numbers, and introduces four new dotted operators | |
321 | (C<&. |. ^. ~.>) that treat their operands consistently as strings. The | |
322 | same applies to the assignment variants (C<&= |= ^= &.= |.= ^.=>). | |
323 | ||
324 | See L<perlop/Bitwise String Operators> for details. | |
325 | ||
193789ac FC |
326 | This feature is available from Perl 5.22 onwards. Starting in Perl 5.28, |
327 | C<use v5.28> will enable the feature. Before 5.28, it was still | |
328 | experimental and would emit a warning in the "experimental::bitwise" | |
329 | category. | |
70ea8edf | 330 | |
5c703779 FC |
331 | =head2 The 'declared_refs' feature |
332 | ||
333 | B<WARNING>: This feature is still experimental and the implementation may | |
334 | change in future versions of Perl. For this reason, Perl will | |
335 | warn when you use the feature, unless you have explicitly disabled the | |
336 | warning: | |
337 | ||
338 | no warnings "experimental::declared_refs"; | |
339 | ||
340 | This allows a reference to a variable to be declared with C<my>, C<state>, | |
341 | our C<our>, or localized with C<local>. It is intended mainly for use in | |
342 | conjunction with the "refaliasing" feature. See L<perlref/Declaring a | |
343 | Reference to a Variable> for examples. | |
344 | ||
345 | This feature is available from Perl 5.26 onwards. | |
346 | ||
bc9b29db RH |
347 | =head1 FEATURE BUNDLES |
348 | ||
0b25e784 | 349 | It's possible to load multiple features together, using |
b22bbcf0 | 350 | a I<feature bundle>. The name of a feature bundle is prefixed with |
0b25e784 DG |
351 | a colon, to distinguish it from an actual feature. |
352 | ||
353 | use feature ":5.10"; | |
354 | ||
355 | The following feature bundles are available: | |
356 | ||
357 | bundle features included | |
358 | --------- ----------------- | |
01868d00 | 359 | :default array_base |
0b25e784 | 360 | |
01868d00 | 361 | :5.10 say state switch array_base |
0b25e784 | 362 | |
01868d00 | 363 | :5.12 say state switch unicode_strings array_base |
0b25e784 | 364 | |
01868d00 | 365 | :5.14 say state switch unicode_strings array_base |
0b25e784 DG |
366 | |
367 | :5.16 say state switch unicode_strings | |
2a4315f8 | 368 | unicode_eval evalbytes current_sub fc |
0b25e784 | 369 | |
52fc5c56 FC |
370 | :5.18 say state switch unicode_strings |
371 | unicode_eval evalbytes current_sub fc | |
372 | ||
d09258e7 RS |
373 | :5.20 say state switch unicode_strings |
374 | unicode_eval evalbytes current_sub fc | |
375 | ||
b530a4ea RS |
376 | :5.22 say state switch unicode_strings |
377 | unicode_eval evalbytes current_sub fc | |
378 | ||
6031f0d2 RS |
379 | :5.24 say state switch unicode_strings |
380 | unicode_eval evalbytes current_sub fc | |
1c2511e0 | 381 | postderef_qq |
6031f0d2 | 382 | |
2c5484a6 RS |
383 | :5.26 say state switch unicode_strings |
384 | unicode_eval evalbytes current_sub fc | |
385 | postderef_qq | |
386 | ||
c35a148e S |
387 | :5.28 say state switch unicode_strings |
388 | unicode_eval evalbytes current_sub fc | |
401d2aaa | 389 | postderef_qq bitwise |
c35a148e | 390 | |
01868d00 FC |
391 | The C<:default> bundle represents the feature set that is enabled before |
392 | any C<use feature> or C<no feature> declaration. | |
a3a91442 JV |
393 | |
394 | Specifying sub-versions such as the C<0> in C<5.14.0> in feature bundles has | |
b22bbcf0 | 395 | no effect. Feature bundles are guaranteed to be the same for all sub-versions. |
bc9b29db | 396 | |
0b25e784 DG |
397 | use feature ":5.14.0"; # same as ":5.14" |
398 | use feature ":5.14.1"; # same as ":5.14" | |
a3a91442 | 399 | |
7dfde25d RGS |
400 | =head1 IMPLICIT LOADING |
401 | ||
0b25e784 DG |
402 | Instead of loading feature bundles by name, it is easier to let Perl do |
403 | implicit loading of a feature bundle for you. | |
404 | ||
405 | There are two ways to load the C<feature> pragma implicitly: | |
7dfde25d RGS |
406 | |
407 | =over 4 | |
408 | ||
409 | =item * | |
410 | ||
0b25e784 DG |
411 | By using the C<-E> switch on the Perl command-line instead of C<-e>. |
412 | That will enable the feature bundle for that version of Perl in the | |
413 | main compilation unit (that is, the one-liner that follows C<-E>). | |
7dfde25d RGS |
414 | |
415 | =item * | |
416 | ||
0b25e784 | 417 | By explicitly requiring a minimum Perl version number for your program, with |
b22bbcf0 | 418 | the C<use VERSION> construct. That is, |
7dfde25d | 419 | |
0b25e784 | 420 | use v5.10.0; |
7dfde25d RGS |
421 | |
422 | will do an implicit | |
423 | ||
39ec54a5 | 424 | no feature ':all'; |
82cfb3a2 | 425 | use feature ':5.10'; |
7dfde25d | 426 | |
b22bbcf0 FC |
427 | and so on. Note how the trailing sub-version |
428 | is automatically stripped from the | |
82cfb3a2 | 429 | version. |
7dfde25d | 430 | |
8d115822 RB |
431 | But to avoid portability warnings (see L<perlfunc/use>), you may prefer: |
432 | ||
433 | use 5.010; | |
434 | ||
435 | with the same effect. | |
436 | ||
0b25e784 | 437 | If the required version is older than Perl 5.10, the ":default" feature |
01868d00 | 438 | bundle is automatically loaded instead. |
70397346 | 439 | |
affe54fa AC |
440 | Unlike C<use feature ":5.12">, saying C<use v5.12> (or any higher version) |
441 | also does the equivalent of C<use strict>; see L<perlfunc/use> for details. | |
442 | ||
7dfde25d RGS |
443 | =back |
444 | ||
0d863452 RH |
445 | =cut |
446 | ||
447 | sub import { | |
22055af9 | 448 | shift; |
36143a0c NC |
449 | |
450 | if (!@_) { | |
0b25e784 | 451 | croak("No features specified"); |
0d863452 | 452 | } |
36143a0c | 453 | |
d3757264 | 454 | __common(1, @_); |
0d863452 RH |
455 | } |
456 | ||
457 | sub unimport { | |
22055af9 | 458 | shift; |
0d863452 | 459 | |
39ec54a5 | 460 | # A bare C<no feature> should reset to the default bundle |
bc9b29db | 461 | if (!@_) { |
39ec54a5 RS |
462 | $^H &= ~($hint_uni8bit|$hint_mask); |
463 | return; | |
bc9b29db RH |
464 | } |
465 | ||
d3757264 NC |
466 | __common(0, @_); |
467 | } | |
468 | ||
469 | ||
470 | sub __common { | |
471 | my $import = shift; | |
0c8d5017 NC |
472 | my $bundle_number = $^H & $hint_mask; |
473 | my $features = $bundle_number != $hint_mask | |
474 | && $feature_bundle{$hint_bundles[$bundle_number >> $hint_shift]}; | |
475 | if ($features) { | |
da5b5421 | 476 | # Features are enabled implicitly via bundle hints. |
d9ee6ccb NC |
477 | # Delete any keys that may be left over from last time. |
478 | delete @^H{ values(%feature) }; | |
479 | $^H |= $hint_mask; | |
480 | for (@$features) { | |
481 | $^H{$feature{$_}} = 1; | |
482 | $^H |= $hint_uni8bit if $_ eq 'unicode_strings'; | |
483 | } | |
da5b5421 | 484 | } |
bc9b29db | 485 | while (@_) { |
0b25e784 DG |
486 | my $name = shift; |
487 | if (substr($name, 0, 1) eq ":") { | |
488 | my $v = substr($name, 1); | |
489 | if (!exists $feature_bundle{$v}) { | |
490 | $v =~ s/^([0-9]+)\.([0-9]+).[0-9]+$/$1.$2/; | |
491 | if (!exists $feature_bundle{$v}) { | |
492 | unknown_feature_bundle(substr($name, 1)); | |
493 | } | |
494 | } | |
495 | unshift @_, @{$feature_bundle{$v}}; | |
496 | next; | |
497 | } | |
36143a0c | 498 | if (!exists $feature{$name}) { |
db629560 FC |
499 | if (exists $noops{$name}) { |
500 | next; | |
501 | } | |
0b25e784 DG |
502 | unknown_feature($name); |
503 | } | |
d3757264 NC |
504 | if ($import) { |
505 | $^H{$feature{$name}} = 1; | |
506 | $^H |= $hint_uni8bit if $name eq 'unicode_strings'; | |
507 | } else { | |
0b25e784 | 508 | delete $^H{$feature{$name}}; |
1863b879 | 509 | $^H &= ~ $hint_uni8bit if $name eq 'unicode_strings'; |
0b25e784 | 510 | } |
0d863452 | 511 | } |
0d863452 RH |
512 | } |
513 | ||
b42943c4 RGS |
514 | sub unknown_feature { |
515 | my $feature = shift; | |
516 | croak(sprintf('Feature "%s" is not supported by Perl %vd', | |
0b25e784 | 517 | $feature, $^V)); |
b42943c4 RGS |
518 | } |
519 | ||
520 | sub unknown_feature_bundle { | |
521 | my $feature = shift; | |
522 | croak(sprintf('Feature bundle "%s" is not supported by Perl %vd', | |
0b25e784 | 523 | $feature, $^V)); |
b42943c4 RGS |
524 | } |
525 | ||
526 | sub croak { | |
527 | require Carp; | |
528 | Carp::croak(@_); | |
529 | } | |
530 | ||
0d863452 | 531 | 1; |
69bcf1d3 FC |
532 | |
533 | # ex: set ro: |