NAME

    Perl::Critic::Policy::Plicease::ProhibitArrayAssignAref - Don't assign
    an anonymous arrayref to an array

VERSION

    version 100.00

DESCRIPTION

    This policy is a fork of
    Perl::Critic::Policy::ValuesAndExpressions::ProhibitArrayAssignAref. It
    differs from the original by not having a dependency on
    List::MoreUtils. It is unfortunately still licensed as GPL3.

    It asks you not to assign an anonymous arrayref to an array

        @array = [ 1, 2, 3 ];       # bad

    The idea is that it's rather unclear whether an arrayref is intended,
    or might have meant to be a list like

        @array = ( 1, 2, 3 );

    This policy is under the "bugs" theme (see "POLICY THEMES" in
    Perl::Critic) for the chance [] is a mistake, and since even if it's
    correct it will likely make anyone reading it wonder.

    A single arrayref can still be assigned to an array, but with parens to
    make it clear,

        @array = ( [1,2,3] );       # ok

    Dereferences or array and hash slices (see "Slices" in perldata) are
    recognised as an array target and treated similarly,

        @$ref = [1,2,3];            # bad assign to deref
        @{$ref} = [1,2,3];          # bad assign to deref
        @x[1,2,3] = ['a','b','c'];  # bad assign to array slice
        @x{'a','b'} = [1,2];        # bad assign to hash slice

 List Assignment Parens

    This policy is not a blanket requirement for () parens on array
    assignments. It's normal and unambiguous to have a function call or
    grep etc without parens.

        @array = foo();                    # ok
        @array = grep {/\.txt$/} @array;   # ok

    The only likely problem from lack of parens in such cases is that the ,
    comma operator has lower precedence than = (see perlop), so something
    like

        @array = 1,2,3;   # oops, not a list

    means

        @array = (1);
        2;
        3;

    Normally the remaining literals in void context provoke a warning from
    Perl itself.

    An intentional single element assignment is quite common as a
    statement, for instance

        @ISA = 'My::Parent::Class';   # ok

    And for reference the range operator precedence is high enough,

        @array = 1..10;               # ok

    But of course parens are needed if concatenating some disjoint ranges
    with the comma operator,

        @array = (1..5, 10..15);      # parens needed

    The qw form gives a list too

        @array = qw(a b c);           # ok

SEE ALSO

    Perl::Critic

    Perl::Critic::Policy::ValuesAndExpressions::ProhibitArrayAssignAref

HOME PAGE

    https://github.com/uperl/Perl-Critic-Policy-Plicease-ProhibitArrayAssignAref

COPYRIGHT

    Copyright 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2019, 2021 Kevin
    Ryde

    Perl-Critic-Policy-Plicease-ProhibitArrayAssignAref is free software;
    you can redistribute it and/or modify it under the terms of the GNU
    General Public License as published by the Free Software Foundation;
    either version 3, or (at your option) any later version.

    Perl-Critic-Policy-Plicease-ProhibitArrayAssignAref is distributed in
    the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
    the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
    PURPOSE. See the GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along
    with Perl-Critic-Policy-Plicease-ProhibitArrayAssignAref. If not, see
    <http://www.gnu.org/licenses>.

AUTHOR

    Original author: Kevin Ryde

    Current maintainer: Graham Ollis <plicease@cpan.org>

COPYRIGHT AND LICENSE

    This software is Copyright (c) 2011-2021 by Kevin Ryde.

    This is free software, licensed under:

      The GNU General Public License, Version 3, June 2007

