Change 13670 by jhi@alpha on 2001/12/13 13:32:37
Subject: Clarifying the documentation of goto
From: "Benjamin J. Tilly" <[EMAIL PROTECTED]>
Date: Thu, 13 Dec 2001 08:57:38 -0500
Message-ID: <[EMAIL PROTECTED]>
Affected files ...
.... //depot/perl/pod/perlfunc.pod#283 edit
Differences ...
==== //depot/perl/pod/perlfunc.pod#283 (text) ====
Index: perl/pod/perlfunc.pod
--- perl/pod/perlfunc.pod.~1~ Thu Dec 13 06:45:06 2001
+++ perl/pod/perlfunc.pod Thu Dec 13 06:45:06 2001
@@ -2083,6 +2083,9 @@
including out of subroutines, but it's usually better to use some other
construct such as C<last> or C<die>. The author of Perl has never felt the
need to use this form of C<goto> (in Perl, that is--C is another matter).
+(The difference being that C does not offer named loops combined with
+loop control. Perl does, and this replaces most structured uses of C<goto>
+in other languages.)
The C<goto-EXPR> form expects a label name, whose scope will be resolved
dynamically. This allows for computed C<goto>s per FORTRAN, but isn't
@@ -2090,13 +2093,14 @@
goto ("FOO", "BAR", "GLARCH")[$i];
-The C<goto-&NAME> form is quite different from the other forms of C<goto>.
-In fact, it isn't a goto in the normal sense at all, and doesn't have
-the stigma associated with other gotos. Instead, it
-substitutes a call to the named subroutine for the currently running
-subroutine. This is used by C<AUTOLOAD> subroutines that wish to load
-another subroutine and then pretend that the other subroutine had been
-called in the first place (except that any modifications to C<@_>
+The C<goto-&NAME> form is quite different from the other forms of
+C<goto>. In fact, it isn't a goto in the normal sense at all, and
+doesn't have the stigma associated with other gotos. Instead, it
+exits the current subroutine (losing any changes set by local()) and
+immediately calls in its place the named subroutine using the current
+value of @_. This is used by C<AUTOLOAD> subroutines that wish to
+load another subroutine and then pretend that the other subroutine had
+been called in the first place (except that any modifications to C<@_>
in the current subroutine are propagated to the other subroutine.)
After the C<goto>, not even C<caller> will be able to tell that this
routine was called first.
End of Patch.
