.\" Automatically generated by Pod::Man 4.14 (Pod::Simple 3.40) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" ======================================================================== .\" .IX Title "Perl::Critic::Policy::Compatibility::ConstantPragmaHash 3pm" .TH Perl::Critic::Policy::Compatibility::ConstantPragmaHash 3pm "2021-02-28" "perl v5.32.1" "User Contributed Perl Documentation" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" Perl::Critic::Policy::Compatibility::ConstantPragmaHash \- new enough "constant" module for multiple constants .SH "DESCRIPTION" .IX Header "DESCRIPTION" This policy is part of the \f(CW\*(C`Perl::Critic::Pulp\*(C'\fR add-on. It requires that when you use the hash style multiple constants of \&\f(CW\*(C`use constant\*(C'\fR that you explicitly declare either Perl 5.8 or \f(CW\*(C`constant\*(C'\fR 1.03 or higher. .PP .Vb 1 \& use constant { AA => 1, BB => 2 }; # bad \& \& use 5.008; \& use constant { CC => 1, DD => 2 }; # ok \& \& use constant 1.03; \& use constant { EE => 1, FF => 2 }; # ok \& \& use constant 1.03 { GG => 1, HH => 2 }; # ok .Ve .PP The idea is to keep you from using the multi-constant feature in code which might run on Perl 5.6, or might in principle still run there. On that basis this policy is under the \*(L"compatibility\*(R" theme (see \*(L"\s-1POLICY THEMES\*(R"\s0 in Perl::Critic). .PP If you declare \f(CW\*(C`constant 1.03\*(C'\fR then the code can still run on Perl 5.6 and perhaps earlier if the user gets a suitably newer \f(CW\*(C`constant\*(C'\fR module from \&\s-1CPAN.\s0 Or of course for past compatibility just don't use the hash style at all! .SS "Details" .IX Subsection "Details" A version declaration must be before the first multi-constant, so it's checked before the multi-constant is attempted and gives an obscure error. .PP .Vb 2 \& use constant { X => 1, Y => 2 }; # bad \& use 5.008; .Ve .PP A \f(CW\*(C`require\*(C'\fR for the perl version is not enough since \f(CW\*(C`use constant\*(C'\fR is at \&\f(CW\*(C`BEGIN\*(C'\fR time, before plain code. .PP .Vb 2 \& require 5.008; # doesn\*(Aqt run early enough \& use constant { X => 1, Y => 2 }; # bad .Ve .PP But a \f(CW\*(C`require\*(C'\fR within a \f(CW\*(C`BEGIN\*(C'\fR block is ok (a past style, still found occasionally). .PP .Vb 2 \& BEGIN { require 5.008 } \& use constant { X => 1, Y => 2 }; # ok \& \& BEGIN { \& require 5.008; \& and_other_setups ...; \& } \& use constant { X => 1, Y => 2 }; # ok .Ve .PP Currently \f(CW\*(C`ConstantPragmaHash\*(C'\fR pays no attention to any conditionals within the \f(CW\*(C`BEGIN\*(C'\fR, it assumes any \f(CW\*(C`require\*(C'\fR there always runs. It could be tricked by some obscure tests but hopefully anything like that is rare or does the right thing anyway. .PP A quoted version number like .PP .Vb 1 \& use constant \*(Aq1.03\*(Aq; # no good .Ve .PP is no good, only a bare number is recognised by \f(CW\*(C`use\*(C'\fR and acted on by ConstantPragmaHash. A string like that goes through to \f(CW\*(C`constant\*(C'\fR as if a name to define (which you'll see it objects to as soon as you try run it). .SS "Drawbacks" .IX Subsection "Drawbacks" Explicitly adding required version numbers in the code can be irritating, especially if other things you're doing only run on 5.8 up anyway. But declaring what code needs is accurate, it allows maybe for backports of modules, and explicit versions can be grepped out to create or check \&\fIMakefile.PL\fR or \fIBuild.PL\fR prereqs. .PP As always if you don't care about this or if you only ever use Perl 5.8 anyway then you can disable \f(CW\*(C`ConstantPragmaHash\*(C'\fR from your \fI.perlcriticrc\fR in the usual way (see \*(L"\s-1CONFIGURATION\*(R"\s0 in Perl::Critic), .PP .Vb 1 \& [\-Compatibility::ConstantPragmaHash] .Ve .SH "SEE ALSO" .IX Header "SEE ALSO" Perl::Critic::Pulp, Perl::Critic, Perl::Critic::Policy::Compatibility::ConstantLeadingUnderscore, Perl::Critic::Policy::ValuesAndExpressions::ProhibitConstantPragma, Perl::Critic::Policy::Modules::RequirePerlVersion .PP constant, \&\*(L"Constant Functions\*(R" in perlsub .SH "HOME PAGE" .IX Header "HOME PAGE" .SH "COPYRIGHT" .IX Header "COPYRIGHT" Copyright 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2019, 2021 Kevin Ryde .PP Perl-Critic-Pulp is free software; you can redistribute it and/or modify it under the terms of the \s-1GNU\s0 General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. .PP Perl-Critic-Pulp is distributed in the hope that it will be useful, but \&\s-1WITHOUT ANY WARRANTY\s0; without even the implied warranty of \s-1MERCHANTABILITY\s0 or \s-1FITNESS FOR A PARTICULAR PURPOSE.\s0 See the \s-1GNU\s0 General Public License for more details. .PP You should have received a copy of the \s-1GNU\s0 General Public License along with Perl-Critic-Pulp. If not, see .