Perl::Critic::Policy::CodeLayout::ProhibitQuotedWordLists - Write qw(foo bar baz) instead of ('foo', 'bar', 'baz').






Conway doesn't mention this, but I think qw() is an underused feature of Perl. Whenever you need to declare a list of one-word literals, the qw() operator is wonderfully concise, and makes it easy to add to the list in the future.

    @list = ('foo', 'bar', 'baz');  #not ok
    @list = qw(foo bar baz);        #ok
    use Foo ('foo', 'bar', 'baz');  #not ok
    use Foo qw(foo bar baz);        #ok


This policy can be configured to only pay attention to word lists with at least a particular number of elements. By default, this value is 2, which means that lists containing zero or one elements are ignored. The minimum list size to be looked at can be specified by giving a value for min_elements in .perlcriticrc like this:

    min_elements = 4

This would cause this policy to only complain about lists containing four or more words.

By default, this policy won't complain if any of the values in the list contain non-word characters. If you want it to, set the strict option to a true value.

    strict = 1


In the PPI parlance, a "list" is almost anything with parentheses. I've tried to make this Policy smart by targeting only "lists" that could be sensibly expressed with qw(). However, there may be some edge cases that I haven't covered. If you find one, send me a note.


This policy was formerly called RequireQuotedWords which seemed a little counter-intuitive. If you get lots of "Cannot load policy module" errors, then you probably need to change RequireQuotedWords to ProhibitQuotedWordLists in your .perlcriticrc file.


Jeffrey Ryan Thalhammer <>


