I'm trying to use a code evaluation assertion in a regex inside of a subroutine, and I'm seeing this strange behavior where it only executes the code the first time that I call the subroutine. Here is the simplest example I could come up with:
sub regex {
my $in = shift;
my $ret = '';
# Assign something to $ret in a code assertion
$in =~ m/^(a)(?{$ret=1})/;
return $ret;
}
while(<DATA>) {
print regex($_) . ".";
}
__DATA__
a
b
a
abcd
bcda
The output that I get is "1...." when I would expect to get "1.1.1.1.1." As I understand it, the value 1 should get assigned to $ret every time through the regex, regardless of whether ^(a) matched.
Can anyone explain this? I'm rather confused.
-
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.
|