From d219a89d8d6ecc553851687967473665a78c77c8 Mon Sep 17 00:00:00 2001
From: dakkar <dakkar@thenautilus.net>
Date: Sun, 13 Feb 2011 18:47:12 +0000
Subject: some more notes on an optimizer

---
 lib/Tree/Transform/XSLTish/Optimizer.pod | 58 +++++++++++++++++++++++++++++++-
 1 file changed, 57 insertions(+), 1 deletion(-)

(limited to 'lib/Tree/Transform/XSLTish/Optimizer.pod')

diff --git a/lib/Tree/Transform/XSLTish/Optimizer.pod b/lib/Tree/Transform/XSLTish/Optimizer.pod
index ce855d5..e721e72 100644
--- a/lib/Tree/Transform/XSLTish/Optimizer.pod
+++ b/lib/Tree/Transform/XSLTish/Optimizer.pod
@@ -1,4 +1,6 @@
-C</> is in fact C</child:> (so C</whatever:foo> does not count)
+=head1 random notes
+
+C</> is in fact C</child::> (so C</whatever::foo> does not count)
 C<//> can also be C<descendants(-or-self)?> (check that option)
 C<..> can also be C<parent>
 
@@ -11,3 +13,57 @@ path contains C</> but no C<//>, apply only at C<count('/') - count('..')> upwar
 path contains C</> but no C<..>, start at C<count('/') - count('..')> upwards (ok, C<//> counts as 1 C</>) and go up to root
 
 what about C<ancestors(-or-self)?> ??
+
+
+--------
+
+an optimizer takes a match rule and adds three slots:
+
+=over 4
+
+=item C<opt_pattern>
+
+a pattern to use instead of the C<match> one
+
+=item C<expected_result>
+
+enum, specifying what the pattern (either C<match> or C<opt_pattern>)
+should return for this rule to be considered matching:
+
+=over 8
+
+=item C<this>
+
+the node we are applying the rule to
+
+=item C<any>
+
+any node
+
+=back
+
+=item C<min_depth>
+
+the minimum depth (on the C<ancestor-or-self::> axis) to test; 0 (or
+C<undef>) means start at the current node, 1 means start at its
+parent, and so on
+
+=item C<max_depth>
+
+the maximum depth (on the C<ancestor-or-self::> axis) to test;
+C<undef> means "unlimited", i.e. stop only at the document root
+
+=back
+
+So:
+
+C<< match => 'foo' >> or C<< match => '//foo' >> would produce C<<
+opt_pattern => 'self::foo', min_depth => 0, max_depth => 0 >>
+
+C<< match => 'foo/bar' >> or C<< match => '//foo/bar' >> would produce
+C<< opt_pattern => 'self::bar/parent::foo', min_depth => 0, max_depth
+=> 0 >>
+
+---------
+
+we need a proper structure matcher!
-- 
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