note
Anonymous Monk
<p> And here it is, a bunch <c>
#!/usr/bin/perl --
use strict; use warnings;
use 5.010;
use Data::Dumper::Names;
my $orig = 'Apple iPhone 4 Black Cover';
my $want = 'Appl-iPho-4-Blac-Cove';
say Dumper $orig, $want;
my $trim = join ' ', (split /\s+/, $orig)[0..1];
say Dumper $trim;
say "THE PROBLEM WITH YOUR ATTEMPT IS RETURN VALUE OF SPLIT ", Dumper([ split /\s+/, $orig ]);
say "OF WHICH YOU ONLY TAKE FIRST 2 ", Dumper([ (split /\s+/, $orig)[0..1] ]);
say "YOU NEED MATCH OPERATOR AND MAP AS WELL";
$trim = join '-', map { /^(\w{1,4})/ } split /\s+/, $orig;
say Dumper $want, $trim ;
say "SAME THING USING SUBSTITUTION OPERATOR";
$trim = $orig;
$trim =~ s{
(?:
(\w{1,4}) # capture first 1-to-4 word chars in $1
\w* # match and ignore any remaining words
)
| # or
(\s+) # any save any-amount-of-whitespace into $2
}{
defined $2 # if defined $2
? '-' # then return '-'
: $1; # else return $1
}gex;
say Dumper $want, $trim ;
$trim = $orig;
say "AND MAYBE FASTER, first transliterate spaces into -";
$trim =~ tr/\t\r\n /-/s;
say Dumper $trim;
say "then shorten words to 4 chars using perl 5.10 feature \\K";
$trim =~ s{\w{4}\K\w*}{}g; # ignore first 4 word chars, delete others
say Dumper $want, $trim ;
say "USING MATCH OPERATOR ONLY ";
$trim = join '-', $orig =~ m{(\w{4})\w*\b|(\w{1,3})}g;
say Dumper $want, $trim ;
say "THOSE CAPTURE GROUPS ARE TRICKY ";
$trim = join '-', grep defined, $orig =~ m{(\w{4})\w*\b|(\w{1,3})}g;
say Dumper $want, $trim ;
__END__
$ perl trim.pl
$orig = 'Apple iPhone 4 Black Cover';
$want = 'Appl-iPho-4-Blac-Cove';
$trim = 'Apple iPhone';
THE PROBLEM WITH YOUR ATTEMPT IS RETURN VALUE OF SPLIT $VAR1 = [
'Apple',
'iPhone',
'4',
'Black',
'Cover'
];
OF WHICH YOU ONLY TAKE FIRST 2 $VAR1 = [
'Apple',
'iPhone'
];
YOU NEED MATCH OPERATOR AND MAP AS WELL
$want = 'Appl-iPho-4-Blac-Cove';
$trim = 'Appl-iPho-4-Blac-Cove';
SAME THING USING SUBSTITUTION OPERATOR
$want = 'Appl-iPho-4-Blac-Cove';
$trim = 'Appl-iPho-4-Blac-Cove';
AND MAYBE FASTER, first transliterate spaces into -
$trim = 'Apple-iPhone-4-Black-Cover';
then shorten words to 4 chars using perl 5.10 feature \K
$want = 'Appl-iPho-4-Blac-Cove';
$trim = 'Appl-iPho-4-Blac-Cove';
USING MATCH OPERATOR ONLY
Use of uninitialized value $orig in join or string at trim.pl line 42.
Use of uninitialized value $orig in join or string at trim.pl line 42.
Use of uninitialized value $orig in join or string at trim.pl line 42.
Use of uninitialized value $orig in join or string at trim.pl line 42.
Use of uninitialized value $orig in join or string at trim.pl line 42.
$want = 'Appl-iPho-4-Blac-Cove';
$trim = 'Appl--iPho---4-Blac--Cove-';
THOSE CAPTURE GROUPS ARE TRICKY
$want = 'Appl-iPho-4-Blac-Cove';
$trim = 'Appl-iPho-4-Blac-Cove';
</c>
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