.\" 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::ValuesAndExpressions::ProhibitArrayAssignAref 3pm" .TH Perl::Critic::Policy::ValuesAndExpressions::ProhibitArrayAssignAref 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::ValuesAndExpressions::ProhibitArrayAssignAref \- don't assign an anonymous arrayref to an array .SH "DESCRIPTION" .IX Header "DESCRIPTION" This policy is part of the \f(CW\*(C`Perl::Critic::Pulp\*(C'\fR add-on. It asks you not to assign an anonymous arrayref to an array .PP .Vb 1 \& @array = [ 1, 2, 3 ]; # bad .Ve .PP The idea is that it's rather unclear whether an arrayref is intended, or might have meant to be a list like .PP .Vb 1 \& @array = ( 1, 2, 3 ); .Ve .PP This policy is under the \*(L"bugs\*(R" theme (see \*(L"\s-1POLICY THEMES\*(R"\s0 in Perl::Critic) for the chance \f(CW\*(C`[]\*(C'\fR is a mistake, and since even if it's correct it will likely make anyone reading it wonder. .PP A single arrayref can still be assigned to an array, but with parens to make it clear, .PP .Vb 1 \& @array = ( [1,2,3] ); # ok .Ve .PP Dereferences or array and hash slices (see \*(L"Slices\*(R" in perldata) are recognised as an array target and treated similarly, .PP .Vb 4 \& @$ref = [1,2,3]; # bad assign to deref \& @{$ref} = [1,2,3]; # bad assign to deref \& @x[1,2,3] = [\*(Aqa\*(Aq,\*(Aqb\*(Aq,\*(Aqc\*(Aq]; # bad assign to array slice \& @x{\*(Aqa\*(Aq,\*(Aqb\*(Aq} = [1,2]; # bad assign to hash slice .Ve .SS "List Assignment Parens" .IX Subsection "List Assignment Parens" This policy is not a blanket requirement for \f(CW\*(C`()\*(C'\fR parens on array assignments. It's normal and unambiguous to have a function call or \f(CW\*(C`grep\*(C'\fR etc without parens. .PP .Vb 2 \& @array = foo(); # ok \& @array = grep {/\e.txt$/} @array; # ok .Ve .PP The only likely problem from lack of parens in such cases is that the \f(CW\*(C`,\*(C'\fR comma operator has lower precedence than \f(CW\*(C`=\*(C'\fR (see perlop), so something like .PP .Vb 1 \& @array = 1,2,3; # oops, not a list .Ve .PP means .PP .Vb 3 \& @array = (1); \& 2; \& 3; .Ve .PP Normally the remaining literals in void context provoke a warning from Perl itself. .PP An intentional single element assignment is quite common as a statement, for instance .PP .Vb 1 \& @ISA = \*(AqMy::Parent::Class\*(Aq; # ok .Ve .PP And for reference the range operator precedence is high enough, .PP .Vb 1 \& @array = 1..10; # ok .Ve .PP But of course parens are needed if concatenating some disjoint ranges with the comma operator, .PP .Vb 1 \& @array = (1..5, 10..15); # parens needed .Ve .PP The \f(CW\*(C`qw\*(C'\fR form gives a list too .PP .Vb 1 \& @array = qw(a b c); # ok .Ve .SH "SEE ALSO" .IX Header "SEE ALSO" Perl::Critic, Perl::Critic::Pulp .SH "HOME PAGE" .IX Header "HOME PAGE" http://user42.tuxfamily.org/perl\-critic\-pulp/index.html .SH "COPYRIGHT" .IX Header "COPYRIGHT" Copyright 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 .