Perl::Critic::Policy::ValuesAndExpressions::ProhibitInterpolationOfLiterals(3)NAMEPerl::Critic::Policy::ValuesAndExpressions::ProhibitInterpolationOfLiterals
- Always use single quotes for literal strings.
AFFILIATION
This Policy is part of the core Perl::Critic distribution.
DESCRIPTION
Don't use double-quotes or "qq//" if your string doesn't require
interpolation. This saves the interpreter a bit of work and it lets
the reader know that you really did intend the string to be literal.
print "foobar"; #not ok
print 'foobar'; #ok
print qq/foobar/; #not ok
print q/foobar/; #ok
print "$foobar"; #ok
print "foobar\n"; #ok
print qq/$foobar/; #ok
print qq/foobar\n/; #ok
print qq{$foobar}; #preferred
print qq{foobar\n}; #preferred
Use of double-quotes might be reasonable if the string contains single
quote (') characters:
print "it's me"; # ok, if configuration flag set
CONFIGURATION
The types of quoting styles to exempt from this policy can be
configured via the "allow" option. This must be a whitespace-delimited
combination of some or all of the following styles: "qq{}", "qq()",
"qq[]", and "qq//".
This is useful because some folks have configured their editor to apply
special syntax highlighting within certain styles of quotes. For
example, you can tweak "vim" to use SQL highlighting for everything
that appears within "qq{}" or "qq[]" quotes. But if those strings are
literal, Perl::Critic will complain. To prevent this, put the
following in your .perlcriticrc file:
[ValuesAndExpressions::ProhibitInterpolationOfLiterals]
allow = qq{} qq[]
The flag "allow_if_string_contains_single_quote" permits double-quoted
strings if the string contains a single quote (') character. It
defaults to off; to turn it on put the following in your .perlcriticrc
file:
[ValuesAndExpressions::ProhibitInterpolationOfLiterals]
allow_if_string_contains_single_quote = 1
SEE ALSO
Perl::Critic::Policy::ValuesAndExpressions::RequireInterpolationOfMetachars
AUTHOR
Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>
COPYRIGHT
Copyright (c) 2005-2011 Imaginative Software Systems. All rights
reserved.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself. The full text of this license can
be found in the LICENSE file included with this module.
Perl::Critic::Policy::ValuesAndExpressions::ProhibitInterpolationOfLiterals(3)
