Author: lwall
Date: 2009-11-12 19:35:33 +0100 (Thu, 12 Nov 2009)
New Revision: 29060
Modified:
docs/Perl6/Spec/S04-control.pod
Log:
[S04] liberalize phaser blorsts somewhat for more consistency, PerlJam++
Modified: docs/Perl6/Spec/S04-control.pod
===================================================================
--- docs/Perl6/Spec/S04-control.pod 2009-11-11 18:20:41 UTC (rev 29059)
+++ docs/Perl6/Spec/S04-control.pod 2009-11-12 18:35:33 UTC (rev 29060)
@@ -13,8 +13,8 @@
Created: 19 Aug 2004
- Last Modified: 10 Nov 2009
- Version: 86
+ Last Modified: 12 Nov 2009
+ Version: 87
This document summarizes Apocalypse 4, which covers the block and
statement syntax of Perl.
@@ -1225,6 +1225,8 @@
my $compiletime = BEGIN localtime;
our $temphandle = START maketemp();
+In fact, most of these phasers will take either a block or a statement
+(known as a I<blorst> in the vernacular).
This can be particularly useful to expose a lexically scoped
declaration to the surrounding context. Hence these declare the same
variables with the same scope as the preceding example, but run the
@@ -1236,6 +1238,20 @@
(Note, however, that the value of a variable calculated at compile
time may not persist under run-time cloning of any surrounding closure.)
+Most of the non-value-producing phasers may also be so used:
+
+ END say my $accumulator;
+
+Note, however, that
+
+ END say my $accumulator = 0;
+
+sets the variable to 0 at C<END> time, since that is when the "my"
+declaration is actually executed. Only argumentless phasers may
+use the statement form. This means that C<CHECK> and C<CONTROL>
+always require a block, since they take an argument that sets C<$_>
+to the current topic.
+
Code that is generated at run time can still fire off C<CHECK>
and C<INIT> phasers, though of course those phasers can't do things that
would require travel back in time. You need a wormhole for that.
