Change 25164 by [EMAIL PROTECTED] on 2005/07/18 08:38:27
Subject: Re: Why does our() cross packages? (PATCH)
From: Michael G Schwern <[EMAIL PROTECTED]>
Date: Fri, 15 Jul 2005 14:35:18 -0700
Message-ID: <[EMAIL PROTECTED]>
(with minor tweaks suggested in subsequent posts)
Affected files ...
... //depot/perl/pod/perlfunc.pod#479 edit
Differences ...
==== //depot/perl/pod/perlfunc.pod#479 (text) ====
Index: perl/pod/perlfunc.pod
--- perl/pod/perlfunc.pod#478~25157~ Sat Jul 16 01:07:44 2005
+++ perl/pod/perlfunc.pod Mon Jul 18 01:38:27 2005
@@ -3263,17 +3263,20 @@
=item our TYPE EXPR : ATTRS
C<our> associates a simple name with a package variable in the current
-package for the remander of the lexical scope. The listed variables
-are declared to be valid globals within the enclosing block, file, or
-C<eval>. That is, it has the same scoping rules as a "my"
-declaration, but does not create a local variable. When C<use strict
-'vars'> is in effect, the C<our> declaration lets you use the declared
-global variable without qualifying it with a package name. (But only
-within the lexical scope of the C<our> declaration. In this it
-differs from "use vars", which is package scoped.)
+package for use within the current scope. When C<use strict 'vars'> is in
+effect, C<our> lets you use declared global variables without qualifying
+them with package names, within the lexical scope of the C<our> declaration.
+In this way C<our> differs from C<use vars>, which is package scoped.
+
+Unlike C<my>, which both allocates storage for a variable and associates a
+a simple name with that storage for use within the current scope, C<our>
+associates a simple name with a package variable in the current package,
+for use within the current scope. In other words, C<our> has the same
+scoping rules as C<my>, but does not necessarily create a
+variable.
-If more than one value is listed, the list must be placed in
-parentheses.
+If more than one value is listed, the list must be placed
+in parentheses.
our $foo;
our($bar, $baz);
@@ -3289,11 +3292,15 @@
$bar = 20;
package Bar;
- print $bar; # prints 20 as it refers to $Foo::bar
+ print $bar; # prints 20, as it refers to $Foo::bar
-Multiple C<our> declarations in the same lexical scope are allowed
-if they are in different packages. If they happen to be in the same
-package, Perl will emit warnings if you have asked for them.
+Multiple C<our> declarations with the same name in the same lexical
+scope are allowed if they are in different packages. If they happen
+to be in the same package, Perl will emit warnings if you have asked
+for them, just like multiple C<my> declarations. Unlike a second
+C<my> declaration, which will bind the name to a fresh variable, a
+second C<our> declaration in the same package, in the same scope, is
+merely redundant.
use warnings;
package Foo;
@@ -3304,7 +3311,8 @@
our $bar = 30; # declares $Bar::bar for rest of lexical scope
print $bar; # prints 30
- our $bar; # emits warning
+ our $bar; # emits warning but has no other effect
+ print $bar; # still prints 30
An C<our> declaration may also have a list of attributes associated
with it.
End of Patch.
