perl::critic::policy::builtinfunctions::prohibitbooleangrep(3) [centos man page]
Perl::Critic::Policy::BuiltinFunctions::ProhibitBooleanGUser3Contributed Perl DocumePerl::Critic::Policy::BuiltinFunctions::ProhibitBooleanGrep(3)NAME
Perl::Critic::Policy::BuiltinFunctions::ProhibitBooleanGrep - Use "List::MoreUtils::any" instead of "grep" in boolean context.
AFFILIATION
This Policy is part of the core Perl::Critic distribution.
DESCRIPTION
Using "grep" in boolean context is a common idiom for checking if any elements in a list match a condition. This works because boolean
context is a subset of scalar context, and grep returns the number of matches in scalar context. A non-zero number of matches means a
match.
But consider the case of a long array where the first element is a match. Boolean "grep" still checks all of the rest of the elements
needlessly. Instead, a better solution is to use the "any" function from List::MoreUtils, which short-circuits after the first successful
match to save time.
CONFIGURATION
This Policy is not configurable except for the standard options.
CAVEATS
The algorithm for detecting boolean context takes a LOT of shortcuts. There are lots of known false negatives. But, I was conservative in
writing this, so I hope there are no false positives.
AUTHOR
Chris Dolan <cdolan@cpan.org>
CREDITS
Initial development of this policy was supported by a grant from the Perl Foundation.
COPYRIGHT
Copyright (c) 2007-2011 Chris Dolan. Many 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 v5.16.3 2014-06-09 Perl::Critic::Policy::BuiltinFunctions::ProhibitBooleanGrep(3)
Check Out this Related Man Page
Perl::Critic::Policy::BuiltinFunctions::RequireBlockMap(User Contributed Perl DocumentPerl::Critic::Policy::BuiltinFunctions::RequireBlockMap(3pm)NAME
Perl::Critic::Policy::BuiltinFunctions::RequireBlockMap - Write "map { $_ =~ /$pattern/ } @list" instead of "map /$pattern/, @list".
AFFILIATION
This Policy is part of the core Perl::Critic distribution.
DESCRIPTION
The expression forms of "grep" and "map" are awkward and hard to read. Use the block forms instead.
@matches = grep /pattern/, @list; #not ok
@matches = grep { /pattern/ } @list; #ok
@mapped = map transform($_), @list; #not ok
@mapped = map { transform($_) } @list; #ok
CONFIGURATION
This Policy is not configurable except for the standard options.
SEE ALSO
Perl::Critic::Policy::BuiltinFunctions::ProhibitStringyEval
Perl::Critic::Policy::BuiltinFunctions::RequireBlockGrep
AUTHOR
Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>
COPYRIGHT
Copyright (c) 2005-2011 Imaginative Software Systems. All rights reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of this license
can be found in the LICENSE file included with this module.
perl v5.14.2 2012-06-07 Perl::Critic::Policy::BuiltinFunctions::RequireBlockMap(3pm)
OK here's the situation:
I have got these lines which I have got to parse.
If the line contains a particular string and any element from a previously defined array I need to take that particular line and do some further processing.
if ((grep(/$_/,$1)) && (grep($pattern,@myarr)))
{
#Do... (2 Replies)
I have 1 file that has elements as follows. Also the CVR(10) and the word "SAUCE" only appear once in the file so maybe a grep command would work?
file1
CVR( 9) = 0.385E+05, ! VEHICLE
CVR(10) = 0.246E+05, ! SAUCE
CVR(11) = 0.162E+03, ! VEHICLE
I need to extract the... (6 Replies)
Hi folks...
Relatively new to scripting, but really struggling with something that will no doubt be second nature to most people on here:
Trying to get an exact match on $sub, where sub is an ip address.
subnet ()
{
clear
while true
do
... (18 Replies)
I am writing a Perl script that uses the grep command and instead of writing to the output file it just writes to the screen.
#!/usr/bin/perl
#
#
@ffiles = `ls CP*BUFFER*.dat`;
foreach my $file (@ffiles){
@data = split(/./, $file);
$filename = $data;
$extension = $data;
#print... (2 Replies)
I have a number of text tab files in my directory named 1.vcf 2.vcf etc. Each file file has headers of 120-130 rows starting with "#", it looks like this
...
##contig=<ID=GL000194.1,length=191469,assembly=hg19>
##contig=<ID=GL000225.1,length=211173,assembly=hg19>... (7 Replies)