Author: larry
Date: Tue Jul 10 18:45:08 2007
New Revision: 14430
Modified:
doc/trunk/design/syn/S09.pod
Log:
Some thinking about how .keys and .shape work on user-defined dimensions
Modified: doc/trunk/design/syn/S09.pod
==============================================================================
--- doc/trunk/design/syn/S09.pod (original)
+++ doc/trunk/design/syn/S09.pod Tue Jul 10 18:45:08 2007
@@ -12,9 +12,9 @@
Maintainer: Larry Wall <[EMAIL PROTECTED]>
Date: 13 Sep 2004
- Last Modified: 2 Jun 2007
+ Last Modified: 10 Jul 2007
Number: 9
- Version: 21
+ Version: 22
=head1 Overview
@@ -548,6 +548,21 @@
@arr{1,3,5}:p[] # 0=>'one', 1=>'two', 2=>'three'
@arr{1,3,5}:p{} # 1=>'one', 3=>'two', 5=>'three'
+The C<.keys> method also returns the keys of all existing elements.
+For a multidimensional array each key is a list containing one value for
+each dimension.
+
+The C<.shape> method also works on such an array; it returns a
+slice of the valid keys for each dimension. The component list
+representing an infinite dimension is necessarily represented lazily.
+(Note that the C<.shape> method returns the possible keys, but the
+cartesian product of the key slice dimensions is not guaranteed to
+index existing elements in every case. That is, this is not intended
+to reflect current combinations of keys in use (use C<:k> for that).
+Note that you have to distingish these two forms:
+
+ @array[].shape # the integer indices
+ @array{}.shape # the user-defined indices
=head1 Inclusive subscripts
