Perl has two scoping mechanisms. Lexical scopes and packages. The key differences between the two are:
There is only one current package.
...
package Foo;
...
package Bar;
...
The program can be in multiple lexical scopes at a time, as long as they are nested.
{
my $foo;
{
my $bar;
...
}
...
}
The lexical state is cleared when the lexical scope is exited.
for (1..2) {
my $x; # New variable each time.
print($x);
}
The package state is persistent.
package Foo;
use Carp qw( carp );
carp('One');
package Bar;
...
package Foo;
carp('Two');
Since the lexical state ceases to exist when exited, it cannot be referenced from the outside.
The package state can be referenced from the outside
package Foo;
use Carp qw( carp );
carp('One');
package Bar;
Foo::carp('Two');
package Foo;
carp('Three');
The use directive itself doesn't know or care about scope. It's all about the code in the import function of the loaded .pm.
use pragma; changes bits in a lexically-scoped compiler variable.
use Module qw( function ); creates a function in the current package.
-
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.
|