Re: in the elemetns of programming perl , I need help with 2 lines that I don't understand

Dr.Ruud wrote:
> Richard Lee schreef:
>
>   
>> $pattern = '.*(?:' . join('|', @ARGV) . ')';
>>     
>
> Safer:
>
>   $pattern = '.*(?:' . join('|', map quotemeta, @ARGV) . ')';
>
> And I would do a qr() on top of that. 
>
>   
} else {
     $pattern = join('', map{"(?=.*$_)"} @ARGV);
}


print "\$pattern is $pattern\n";


[root@RLEE ~]# ./faqgrep -or list
$pattern is .*(?:list)

---------------------- breaking it down on my own------------------------

@_ = shift @ARGV  ==> should be 'list'
map{"(?=.*$_)"}       ==> positive look ahead on anything followed by 
pattern 'list'
join()                         ==> shoudln't it be just 'list' ??

but when I print it, I get  .*(?:list).... why???