Author: larry
Date: Fri Aug 18 17:57:09 2006
New Revision: 11155
Modified:
doc/trunk/design/syn/S09.pod
Log:
List comprehensions via junctional syntax.
Modified: doc/trunk/design/syn/S09.pod
==============================================================================
--- doc/trunk/design/syn/S09.pod (original)
+++ doc/trunk/design/syn/S09.pod Fri Aug 18 17:57:09 2006
@@ -12,9 +12,9 @@
Maintainer: Larry Wall <[EMAIL PROTECTED]>
Date: 13 Sep 2004
- Last Modified: 26 July 2006
+ Last Modified: 18 Aug 2006
Number: 9
- Version: 12
+ Version: 13
=head1 Overview
@@ -603,6 +603,22 @@
in fact scalar parameters, though, so you could pass a junction of
array or hash objects.)
+For junctions used with chained operators in a list context, the resulting
+value will be a subset of the first C<any> used in comparison:
+
+ for 0 <= any(@x) < all(@y) {...}
+
+will use only those values from C<@x> that satisfy the constraint.
+Usually junctions do not guarantee order of evalution, but in
+this particular case, the original ordering C<@x> is guaranteed to
+be preserved in the returned list. In particular,
+
+ @result = any(@x) ~~ {...};
+
+is equivalent to
+
+ @result = grep {...}, @x;
+
=head1 Parallelized parameters and autothreading
Within the scope of a C<use autoindex> pragma (or equivalent, such as
