Greetings jesuashok,
It's a very curious line, and others have explained what it does already; however, it has a couple negatives: It's not easily understood, and it's slower than a more easily understood alternative.
use strict;
use warnings;
use Benchmark qw(cmpthese);
cmpthese(
100000,
{
'ahash' => sub {
my $pat = {qw(a - b = c ~ d ^)}->{substr($0, 0, 1)};
},
'tr' => sub {
(my $pat = substr($0, 0, 1)) =~ tr/abcd/-=~^/;
},
},
);
The above benchmark returns this:
Rate ahash tr
ahash 75120/s -- -86%
tr 541712/s 621% --
It's a nice trick, but I wouldn't use it anywhere except in an obfu.
gryphon
Whitepages.com Development Manager (WDDC)
code('Perl') || die;
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.