Author: audreyt
Date: Sat Sep 23 01:05:45 2006
New Revision: 12346
Modified:
doc/trunk/design/syn/S03.pod
Log:
* S03: Cleanup capture-exploding examples such that |@foo always
simply put @foo's elements as positional arguments, regardless
of whether @foo[0] contains a Hash. (On the other hand,
"[,] @foo" will still happily turn @foo[0] into named argument.)
Modified: doc/trunk/design/syn/S03.pod
==============================================================================
--- doc/trunk/design/syn/S03.pod (original)
+++ doc/trunk/design/syn/S03.pod Sat Sep 23 01:05:45 2006
@@ -12,9 +12,9 @@
Maintainer: Larry Wall <[EMAIL PROTECTED]>
Date: 8 Mar 2004
- Last Modified: 20 Sept 2006
+ Last Modified: 23 Sept 2006
Number: 3
- Version: 67
+ Version: 68
=head1 Changes to Perl 5 operators
@@ -911,7 +911,7 @@
as if they'd been placed there directly.
@args = [EMAIL PROTECTED],1,2,3;
- push [,] @args; # same as push @foo,1,2,3
+ push [,] @args; # same as push(@foo: 1,2,3)
See S06 for more.
@@ -1311,33 +1311,39 @@
is equivalent to:
- push @foo, @bar;
+ push @foo: @bar;
-as is this:
+which is just another way to write:
- my $args = \(@foo, @bar); # construct a Capture object
- push |$args;
+ @foo.push(@bar);
-The C<|> sigil functions as a unary form of the C<[,]>
-list operator, so we could have written the earlier example as:
+The C<|> sigil functions as a unary form of the C<[,]> list operator,
+so the examples above can also be written as.
- my @args = [EMAIL PROTECTED], @bar;
- push |@args;
+ my $args = \(@foo: @bar); # construct a Capture object
+ push |$args; # push(@foo: @bar)
+
+Unlike C<[,]>, C<|> does not flatten its argument, but instead directly
+converts its argument into a C<Capture>:
+
+ my @args = \$x, 1, 2, 3;
+ say [,] @args; # say($x: 1, 2, 3);
+ say |@args; # say(\$x, 1, 2, 3);
-To the extent possible, the C<|> will treat its argument as
-a C<Capture> even if it isn't.
+Because of this, C<|%args> always produces named arguments, and
+C<|@args> always produces positional arguments.
In list context, a C<Scalar> holding an C<Array> object does not flatten.
Hence
$bar = @bar;
- push @foo, $bar;
+ @foo.push($bar);
merely pushes a single C<Array> object onto C<@foo>. You can
explicitly flatten it in one of these ways:
- push @foo, @$bar;
- push @foo, $bar[];
- push @foo, |$bar;
+ @foo.push(@$bar);
+ @foo.push($bar[]);
+ @foo.push(|$bar);
Those three forms work because the slurpy array in C<push>'s signature
flattens the C<Array> object into a list argument.
@@ -1382,7 +1388,7 @@
automatically exploded into their various parts, as if you'd said:
my \$capture := func();
- push [,] $$capture: @$capture, %$capture;
+ push($$capture: @$capture, %$capture);
or some such. The C<[,]> then handles the various zones appropriately
depending on the context. An invocant only makes sense as the first
