{"id":138692,"date":"2025-07-03T23:12:17","date_gmt":"2025-07-03T21:12:17","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/dostupen-yazyk-programmirovaniya-perl-5-42"},"modified":"2025-07-03T23:12:17","modified_gmt":"2025-07-03T21:12:17","slug":"dostupen-yazyk-programmirovaniya-perl-5-42","status":"publish","type":"post","link":"https:\/\/prohoster.info\/en\/blog\/news\/dostupen-yazyk-programmirovaniya-perl-5-42","title":{"rendered":"The programming language Perl 5.42 is now available.","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"
After a year of development, the release of the new stable branch of the Perl programming language \u2014 5.42 has been published. Approximately 280 thousand lines of code were changed (excluding documentation and automatically generated code \u2014 93 thousand), affecting 1500 files, with the involvement of 64 developers. <\/p>\n
Branch 5.42 was released according to the approved fixed development schedule established twelve years ago, which implies the release of new stable branches once a year and corrective releases every three months. The first corrective release Perl 5.42.1 is expected to be released in about a month, which will address the most significant bugs identified during the implementation of Perl 5.42.0. Simultaneously with the release of Perl 5.42, support for the 5.38 branch has ended, with updates for this branch being released in the future only if critical security issues are identified. The process of developing the experimental branch 5.43 will begin shortly, based on which a stable release of Perl 5.44 will be formed in June 2026, unless a decision is made to switch to numbering 7.x. <\/p>\n
Key changes: <\/p>\n
\n
Experimental list processing operators have been added \u2014 \u2018any { BLOCK } @list\u2019 and \u2018all { BLOCK } @list\u2019, which are similar to the \u2018grep { BLOCK } @list\u2019 operator but can return only true or false values. The \u2018all\u2019 operator returns \u2018true\u2019 if the condition is met for all elements of the list, while the \u2018any\u2019 operator returns \u2018true\u2019 if the condition is met for at least one element. The functionality of the operators is similar to the functions from the List::Util module, but the built-in versions are faster and consume less memory. use v5.42; use feature 'keyword_all'; no warnings 'experimental::keyword_all'; my @numbers = ...; if ( all { $_ % 2 == 0 } @numbers ) { say 'All the numbers are even'; }\n
For fields defined within a class, the \u2018:writer\u2019 attribute has been implemented, used for automatically creating a method that writes the value of a variable to the field for the current instance of the class. class Point { field $x :reader :writer :param; field $y :reader :writer :param; } my $p = Point->new( x => 20, y => 40 ); $p->set_x(60);\n
Support for lexical method definitions has been added, allowing methods that are only available within the lexical scope of the block in which they are created, similar to the definition of lexical subs («lexical_subs»). The expression «my \u0438\u043c\u044f_\u043c\u0435\u0442\u043e\u0434\u0430» is used to create such methods.\n
The operator «->&» has been added, allowing for the invocation of subs that are in the lexical scope as if they were methods. Combined with the ability to define lexical methods, the new operator implements functionality similar to private methods.\n
An assignment operator «A ^^= B» has been added, performing the operation «A = A XOR B».\n
The pragma «source::encoding» has been added to define the source code encoding. For code in ASCII encoding, «use source::encoding ‘ascii'» can be specified (default), and for UTF-8 \u2014 «use source::encoding ‘utf8'», with the latter being equivalent to «use utf8». The interpreter will produce an error if UTF-8 characters are found in code marked as ASCII, or if escape sequences «\x{}» are used in code marked as UTF-8. To disable encoding checks for a part of the code, «use no source::encoding» can be used. In practice, the added pragma can be useful for identifying cases where the developer forgot to specify «use utf8» for UTF-8 encoded code.\n
A function chdir() has been added to the namespace «CORE::». For example, this function can now be accessed as «&CORE::chdir($dir)» or «my $ref = \&CORE::chdir; $ref->($dir)».\n
The expression ‘no feature «apostrophe_as_package_separator»‘ has been added to disable the support for using the symbol » ‘ » as a package name separator (e.g., «My’Module’Var» instead of «My::Module::Var»). Initially, in Perl 5.42, there were plans to remove support for such separators, which had previously been deprecated, but discussions concluded that this capability should be retained by default while providing an option to disable it.\n
The functionality of 'switch' and the operator '~~' has been moved to the list of deprecated features that were planned for removal. Starting from Perl versions 5.36 and 5.42, 'switch' and '~~' are disabled by default when binding code to specific versions of the language (for example, when using 'use v5.42'), but can be activated with the statements 'use feature 'switch'' and 'use feature 'smartmatch'.\n
Support for Unicode specification 16.0 has been added. <\/ul>\n