Author: larry
Date: Sat Jun 3 19:13:10 2006
New Revision: 9462
Modified:
doc/trunk/design/syn/S12.pod
Log:
Clarified scoping of "has $x" and friends.
Modified: doc/trunk/design/syn/S12.pod
==============================================================================
--- doc/trunk/design/syn/S12.pod (original)
+++ doc/trunk/design/syn/S12.pod Sat Jun 3 19:13:10 2006
@@ -12,9 +12,9 @@
Maintainer: Larry Wall <[EMAIL PROTECTED]>
Date: 27 Oct 2004
- Last Modified: 8 May 2006
+ Last Modified: 3 Jun 2006
Number: 12
- Version: 15
+ Version: 16
=head1 Overview
@@ -360,14 +360,26 @@
Public attributes have a secondary sigil of "dot", indicating
the automatic generation of an accessor method of the same name.
Private attributes use an exclamation to indicate that no public accessor is
-generated. The exclamation is optional, so these are identical in effect:
+generated.
has $!brain;
- has $brain;
-And any later references to the private variable may either use or
-omit the exclamation, as you wish to emphasize or ignore the privacy
-of the variable.
+The "true name" of the private variable always has the exclamation, but
+much like with C<our> variables, you may declare a lexically scoped alias
+to the private variable by saying:
+
+ has $brain; # also declares $!brain;
+
+And any later references to the private variable within the same block
+may either use or omit the exclamation, as you wish to emphasize or
+ignore the privacy of the variable. Outside the block, you must use
+the C<!> form. If you declare with the C<!> form, you must use that
+form consistently everywhere. If you declare with the C<.> form, you
+also get the private C<!> form as a non-virtual name for the actual
+storage location, and you may use either C<!> or C<.> form anywhere
+within the class, even if the class is reopened. Outside the class
+you must use the public C<.> form, or rely on a method call (which
+can be a private method call, but only for trusted classes).
For public attributes, some traits are copied to the accessor method.
The C<rw> trait causes the generated accessor to be declared C<rw>,
