Perl named operators and builtin subs introduced since 5.6

[ikegami]

Perl named operators and builtin subs introduced since 5.6

Name	Availability	Experimental	In CORE::	Enabling pragma	Enabling feature set
__CLASS__	Since 5.40	—	Since 5.40	use feature qw( class );	—
__SUB__	Since 5.16	—	Since 5.16	use feature qw( current_sub );	5.16 and up
ADJUST	Since 5.38	Since 5.40	Since 5.38	use feature qw( class );	—
all	Since 5.42	Since 5.42	Since 5.42	use feature qw( keyword_all );	—
any	Since 5.42	Since 5.42	Since 5.42	use feature qw( keyword_any );	—
blessed	Since 5.36	From 5.36 until 5.40	—	use builtin qw( blessed );	5.40 and up
break	From 5.10	Since 5.16[1] until 5.38 Deprecated from 5.38 until 5.42	Since 5.16	use feature qw( switch );	From 5.10 up to 5.36
catch	Since 5.34	From 5.34 until 5.40	Since 5.34	use feature qw( try );	5.40 and up
ceil	Since 5.36	From 5.36 until 5.40	—	use builtin qw( ceil );	5.40 and up
class	Since 5.38	Since 5.38	Since 5.38	use feature qw( class );	—
continue	From 5.10	Since 5.16[1] until 5.38 Deprecated from 5.38 until 5.42	Since 5.16	use feature qw( switch );	From 5.10 up to 5.36
created_as_number	Since 5.36	Since 5.36	—	use builtin qw( created_as_number );	—
created_as_string	Since 5.36	Since 5.36	—	use builtin qw( created_as_string );	—
default	From 5.10	Since 5.16[1] until 5.38 Deprecated from 5.38 until 5.42	Since 5.16	use feature qw( switch );	From 5.10 up to 5.36
defer	Since 5.36	Since 5.36	Since 5.36	use feature qw( defer );	5.40 and up
export_lexically	Since 5.38	Since 5.38	—	use builtin qw( export_lexically );	—
false	Since 5.36	From 5.36 until 5.40	—	use builtin qw( false );	—
fc	Since 5.16	—	Since 5.16	use feature qw( fc );	5.16 and up
field	Since 5.38	Since 5.38	Since 5.38	use feature qw( class );	—
floor	Since 5.36	From 5.36 until 5.40	—	use builtin qw( floor );	5.40 and up
finally	Since 5.36	Since 5.36	Since 5.36	use feature qw( try );	5.40 and up
given	From 5.10	Since 5.16[1] until 5.38 Deprecated from 5.38 until 5.42	Since 5.16	use feature qw( switch );	From 5.10 up to 5.36
indexed	Since 5.36	From 5.36 until 5.40	—	use builtin qw( indexed );	5.40 and up
inf	Since 5.40	Since 5.40	—	use builtin qw( inf );	—
is_bool	Since 5.36	Since 5.36	—	use builtin qw( is_bool );	—
is_tainted	Since 5.38	From 5.38 until 5.40	—	use builtin qw( is_tainted );	5.40 and up
is_weak	Since 5.36	From 5.36 until 5.40	—	use builtin qw( is_weak );	5.40 and up
isa	Since 5.32	From 5.32 until 5.34	Since 5.32	use feature qw( isa );	5.36 and up
load_module	Since 5.40	Since 5.40	—	use builtin qw( load_module );	—
method	Since 5.38	Since 5.38	Since 5.38	use feature qw( class );	—
nan	Since 5.40	Since 5.40	—	use builtin qw( nan );	—
refaddr	Since 5.36	From 5.36 until 5.40	—	use builtin qw( refaddr );	5.40 and up
reftype	Since 5.36	From 5.36 until 5.40	—	use builtin qw( reftype );	5.40 and up
say	Since 5.10	—	Since 5.16	use feature qw( say );	5.10 and up
state	Since 5.10	—	Since 5.16	use feature qw( state );	5.10 and up
stringify	Since 5.40	Since 5.40	—	use builtin qw( stringify );	—
trim	Since 5.36	From 5.36 until 5.40	—	use builtin qw( trim );	5.40 and up
true	Since 5.36	From 5.36 until 5.40	—	use builtin qw( true );	5.40 and up
try	Since 5.34	From 5.34 until 5.40	Since 5.34	use feature qw( try );	5.40 and up
unweaken	Since 5.36	From 5.36 until 5.40	—	use builtin qw( unweaken );	5.40 and up
weaken	Since 5.36	From 5.36 until 5.40	—	use builtin qw( weaken );	5.40 and up
when	From 5.10	Since 5.16[1] until 5.38 Deprecated from 5.38 until 5.42	Since 5.16	use feature qw( switch );	From 5.10 up to 5.36
builtin::blessed	Since 5.36	From 5.36 until 5.40	—	Always available
builtin::ceil	Since 5.36	From 5.36 until 5.40	—	Always available
builtin::created_as_number	Since 5.36	Since 5.36	—	Always available
builtin::created_as_string	Since 5.36	Since 5.36	—	Always available
builtin::export_lexically	Since 5.38	Since 5.38	—	Always available
builtin::false	Since 5.36	From 5.36 until 5.40	—	Always available
builtin::floor	Since 5.36	From 5.36 until 5.40	—	Always available
builtin::indexed	Since 5.36	From 5.36 until 5.40	—	Always available
builtin::inf	Since 5.40	Since 5.40	—	Always available
builtin::is_bool	Since 5.36	Since 5.36	—	Always available
builtin::is_tainted	Since 5.38	From 5.38 until 5.40	—	Always available
builtin::is_weak	Since 5.36	From 5.36 until 5.40	—	Always available
builtin::load_module	Since 5.40	Since 5.40	—	Always available
builtin::nan	Since 5.40	Since 5.40	—	Always available
builtin::refaddr	Since 5.36	From 5.36 until 5.40	—	Always available
builtin::reftype	Since 5.36	From 5.36 until 5.40	—	Always available
builtin::stringify	Since 5.40	Since 5.40	—	Always available
builtin::trim	Since 5.36	From 5.36 until 5.40	—	Always available
builtin::true	Since 5.36	From 5.36 until 5.40	—	Always available
builtin::unweaken	Since 5.36	From 5.36 until 5.40	—	Always available
builtin::weaken	Since 5.36	From 5.36 until 5.40	—	Always available
utf8::decode	Since 5.8	—	—	Always available
utf8::downgrade	Since 5.8	—	—	Always available
utf8::encode	Since 5.8	—	—	Always available
utf8::is_utf8	Since 5.8.1	—	—	Always available
utf8::native_to_unicode	Since 5.8[2]	—	—	Always available
utf8::unicode_to_native	Since 5.8[2]	—	—	Always available
utf8::upgrade	Since 5.8	—	—	Always available
utf8::valid	Since 5.8	—	—	Always available

Notes

• Current as of 5.42.
• Perl provides other builtin subs which are meant to be used as methods, which aren't documented to be available at all times, or which aren't documented at all. (These are found in in constant::, Internals::, PerlIO::, re::, Tie::Hash::NamedCapture, UNIVERSAL:: and version::). These are deliberately omitted.
• The existence of dev versions is ignored.
• "Until 5.xx" and "up to 5.xx" are exclusive, meaning they don't include 5.xx.

Footnotes

1. Experimental warnings were only added in 5.18, but the switch feature was documented to be experimental since 5.16.
2. While utf8::native_to_unicode and utf8::unicode_to_native have only been documented since 5.22, they've been available since 5.8.

---

Updates

1. Added the keywords from the class feature.
2. Fixed versions for defer.
3. Fixed versions for finally.
4. Added availability in CORE::.
5. is_tainted, export_lexically, builtin::is_tainted and builtin::export_lexically were missing.
6. Updated for 5.40.
7. Updated for 5.42.

[tobyink]

Good table, but maybe it doesn't need to list everything from builtin twice? Better to just make a note that they can always be used by their fully-qualified name or imported lexically.

[kcott]

G'day ikegami,

++ You've obviously put a lot of work into this.

I haven't actually gone through and checked everything; however, two stood out, possibly because of the additional text: given and when.

According to the documentation, these became experimental in 5.18 (not 5.16). See "perl5180delta: The smartmatch family of features are now experimental".

[ikegami]

I've mistakenly said the feature became experimental in 5.18 in the past too. But while the experimental warnings were added in 5.18, it was flagged as experimental in 5.16.

Quote 5.16's perlsyn,

you can say use feature "switch"; to enable an experimental switch feature.

Also,

Under the "switch" feature, Perl gains the experimental keywords given, when, default, continue, and break.

Added break, default and continue to the table.

[kcott]

++ I never knew that — you learn something every day. Thanks for the info. :-)

[Bod]

Great table - thanks :)

I would have expected to see class in there as that's new in 5.36 isn't it? I've not used it or investigated it as 5.32 is the latest version I have.

[eyepopslikeamosquito]

I would have expected to see class in there as that's new in 5.36 isn't it?

Good point. I just checked perlclass, and I see keywords: class, field and method. Not sure if attributes :isa and :param qualify.

[ikegami]

5.38. Overlooked. Fixed. Thanks.

[freonpsandoz]

Great table, thanks! Is there any way to find out when features other than keywords were added? I'm currently trying to find (1) when ref() began returning 'Regexp' and (2) when class 'Regexp' was added, if that was more recent than (1). Both ref() and Scalar::Util::blessed() return 'Regexp' as of v5.20.2. The referenced 5.38 delta page contains a link to select earlier versions, but it doesn't seem to work; a "raptor not found" error is displayed.

[choroba]

I collect some non-features in Syntax::Construct, but Regexp is not one of them (I might add it, though).

[hippo]

A quick perusal through the docs for ref for historical versions of Perl suggests that the Regexp class started being reported in 5.8.9 but this is not mentioned in the 5.8.9 delta AFAICS. Nowadays that really ought to be so long ago that it doesn't matter anyway.

[ikegami]

It's been that way since at least 5.8.9. ("t" means threaded. Ignore that.)

$ for v in 5.8.9 5.10t 5.12t 5.14t 5.16t 5.18t 5.20t; do
   echo $v
   $v/bin/perl -le'print ref( qr/x/ )'
done
5.8.9
Regexp
5.10t
Regexp
5.12t
Regexp
5.14t
Regexp
5.16t
Regexp
5.18t
Regexp
5.20t
Regexp

[ikegami]

Updated parent for 5.42.