X-Git-Url: https://sipb.mit.edu/gitweb.cgi/ikiwiki.git/blobdiff_plain/0c481bce6e828613406838bc68ed0958459f6a8c..8e4af6a8e2a8e8d9b7d9f4312c4216261ebd5a28:/doc/todo/pagespec_relative_to_a_target.mdwn

diff --git a/doc/todo/pagespec_relative_to_a_target.mdwn b/doc/todo/pagespec_relative_to_a_target.mdwn
index e92988c3e..00030cce6 100644
--- a/doc/todo/pagespec_relative_to_a_target.mdwn
+++ b/doc/todo/pagespec_relative_to_a_target.mdwn
@@ -30,9 +30,9 @@ Note that if you try to inline `*/blah` you will match `foo/blah`,
 themselves rather than any relatives of theirs.
 
 This patch is useful for (among other things) constructing blogging 
-systems where leaf nodes are organized hierarchically; using has_child,
+systems where leaf nodes are organized hierarchically; using `has_child`,
 you can inline only leaf nodes and ignore "intermediate" nodes.
-match_relative can be used recursively to match properties of arbitrary
+`match_relative` can be used recursively to match properties of arbitrary
 complexity: "show me all the pages who have children called foo that 
 have children called blah". I'm not sure what use it is, though.
 
@@ -57,7 +57,7 @@ diff -urNX ignorepats ikiwiki/IkiWiki/Plugin/relative.pm ikidev/IkiWiki/Plugin/r
 +
 +package IkiWiki::PageSpec;
 +
-+sub match_relative($$;@) { #{{{
++sub match_relative($$;@) {
 +	my $parent = shift;
 +	my $spec = shift;
 +	my %params = @_;
@@ -69,21 +69,33 @@ diff -urNX ignorepats ikiwiki/IkiWiki/Plugin/relative.pm ikidev/IkiWiki/Plugin/r
 +		}
 +	}
 +	return IkiWiki::FailReason->new("$parent can't match $spec against anything");
-+} #}}}
++}
 +
-+sub match_has_child($$;@) { #{{{
++sub match_has_child($$;@) {
 +	my $page = shift;
 +	my $childname = shift;
 +	my $spec;
-+	if ($childname) { #{{{
++	if ($childname) {
 +		$spec = "$page/$childname or $page/*/$childname";
-+	} #}}}
-+	else { #{{{
++	}
++	else {
 +		$spec = "$page/*";
-+	} #}}}
++	}
 +
 +	return match_relative($page, $spec, @_);
-+} #}}}
++}
 +
 +1
-</pre>
\ No newline at end of file
+</pre>
+
+[[!tag patch]]
+
+> This looks really interesting.  It reminds me of [[!wikipedia XPath]] and its conditionals.
+> Those might actually work well adapted to pagespecs.  For instance, to write
+> "match any page with a child blah", you could just write *[blah] , or if you
+> don't want to use relative-by-default in the conditionals, *[./blah].
+> -- [[JoshTriplett]]
+
+> And it [[!taglink also_reminds_me|pagespec_in_DL_style]] of [[!wikipedia description logics]]: of course, given the relation `subpage` one could write a description-logic-style formula which would define the class of pages that are ("existentially") in a given relation (`subpage` or `inverse(subpage)*subpage`) to a certain other class of pages (e.g., named "blah") ("existentially" means there must exist a page, e.g., named "blah", which is in the given relation to the candidate).
+
+> Probably the model behind XPath is similar (although I don't know enough to say this definitely).--Ivan Z.