On Sun, Apr 10, 2011 at 12:27 AM, Brian F. Yulga
<byu...@langly.dyndns.org> wrote:
> shawn wilson wrote:
>>
>> On Sat, Apr 9, 2011 at 3:29 PM,<sono...@fannullone.us> wrote:
>>
>>>
>>>> my $address_count = () = $str =~ /box|street|avenue|lane|apo/ig;
>>
>> what does print $var = () = $str =~ /regex/; do?
>> particularly the '= () ='?
>>
>
> According to "Effective Perl Programming (2nd Ed.)", Item 9 (Know the
> difference between lists and arrays)...
> (I couldn't find the text online, so my apologies for poorly paraphrasing
> the book)
> Since the assignment operator is right associative, the '() = ...' happens
> first, which forces the assignment operator to act in list context on the
> regex match on the right. Then the '$var =' to the left is the assignment
> operator in scalar context, which returns the number of elements from the
> list on the right.
>
> This code can be used to count the number of matches from your regex, if you
> don't care to do anything with the actual matches.
>
> my $count =()= m/(.....)/g;
>
> Apparently this is called the "goatse operator". no kidding; that's what
> the book says.
that's cool
>>
>> per the question, maybe something like this:
>> my @match = [ qr/one/i, qr/two/i, qr/etc/i ];
>> my @words = split /[^\s]+/, $fields;
>> my $count = 0;
>> foreach my $word (@words) {
>> $count++ if( $word ~~ @match );
>> }
>> print "cool\n" if $count>= 2;
>>
>>
>
> How does this code work? For one thing, you have @match = [ ]; which is
> assigning an array reference to an array? Maybe I'm not understanding
> something... I tweaked your code to the following, since I had problems
> compiling it as you wrote it:
>
heh, i've got to learn to test my code before posting - i'm ending
looking like an idiot :)
*sigh* this is what i wanted to say:
#!/usr/bin/perl
use warnings;
use strict;
my $fields1 = "a little sentense with one and it will match with two\n";
my $fields2 = "this one will not match\n";
work( $fields1 );
work( $fields2 );
sub work {
my( $fields ) = @_;
my @match = ( qr/one/i, qr/two/i, qr/etc/i );
my @words = split /\W+/, $fields;
my $count = 0;
foreach my $word (@words) {
$count++ if( $word ~~ @match );
}
print "String: $fields\n";
print "matched $count\n" if $count >= 2;
}
now, as i stated earlier, when you do matching like that ( $word ~~
@match ) it only matches the first thing that hits. so, if you change
the later part of that function to:
my $count = () = $fields ~~ @match;
print "$count\n";
it'll print 1 for each string you run through. and as i stated
earlier, if anyone knows how to change this behavior (without
overloading) i'd be interested.
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