I like the idea of [[tips/integrated_issue_tracking_with_ikiwiki]], and I do so on several wikis. However, as far as I can tell, ikiwiki has no functionality which can represent dependencies between bugs and allow pagespecs to select based on dependencies. For instance, I can't write a pagespec which selects all bugs with no dependencies on bugs not marked as done. --[[JoshTriplett]]
+
+> I started having a think about this. I'm going to start with the idea that expanding
+> the pagespec syntax is the way to attack this. It seems that any pagespec that is going
+> to represent "all bugs with no dependencies on bugs not marked as done" is going to
+> need some way to represent "bugs not marked as done" as a collection of pages, and
+> then represent "bugs which do not link to pages in the previous collection".
+>
+> One way to do this would be to introduce variables into the pagespec, along with
+> universal and/or existential [[!wikipedia Quantification]]. That looks quite complex.
+>
+>> I thought about this briefly, and got about that far.. glad you got
+>> further. :-) --[[Joey]]
+>
+> Another option would be go with a more functional syntax. The concept here would
+> be to allow a pagespec to appear in a 'pagespec function' anywhere a page can. e.g.
+> I could pass a pagespec to `link()` and that would return true if there is a link to any
+> page matching the pagespec. This makes the variables and existential quantification
+> implicit. It would allow the example requested above:
+>
+>> `bugs/* and !*/Discussion and !link(bugs/* and !*/Discussion and !link(done))`
+>
+> Unfortunately, this is also going to make the pagespec parsing more complex because
+> we now need to parse nested sets of parentheses to know when the nested pagespec
+> ends, and that isn't a regular language (we can't use regular expression matching for
+> easy parsing).
+>
+>> Also, it may cause ambiguities with page names that contain parens
+>> (though some such ambigutities already exist with the pagespec syntax).
+>
+> One simplification of that would be to introduce some pagespec [[shortcuts]]. We could
+> then allow pagespec functions to take either pages, or named pagespec shortcuts. The
+> pagespec shortcuts would just be listed on a special page, like current [[shortcuts]].
+> (It would probably be a good idea to require that shortcuts on that page can only refer
+> to named pagespecs higher up that page than themselves. That would stop some
+> looping issues...) These shortcuts would be used as follows: when trying to match
+> a page (without globs) you look to see if the page exists. If it does then you have a
+> match. If it doesn't, then you look to see if a similarly named pagespec shortcut
+> exists. If it does, then you check that pagespec recursively to see if you have a match.
+> The ordering requirement on named pagespecs stops infinite recursion.
+>
+> Does that seem like a reasonable first approach?
+>
+> -- [[Will]]
+
+>> Having a separate page for the shortcuts feels unwieldly.. perhaps
+>> instead the shortcut could be defined earlier in the scope of the same
+>> pagespec that uses it?
+>>
+>> Example: `define(~bugs, bugs/* and !*/Discussion) and define(~openbugs, ~bugs and !link(done)) and ~openbugs and !link(~openbugs)`
+
+>>> That could work. parens are only ever nested 1 deep in that grammar so it is regular and the current parsing would be ok.
+
+>> Note that I made the "~" explicit, not implicit, so it could be left out. In the case of ambiguity between
+>> a definition and a page name, the definition would win.
+
+>>> That was my initial thought too :), but when implementing it I decided that requiring the ~ made things easier. I'll probably require the ~ for the first pass at least.
+
+>> So, equivilant example: `define(bugs, bugs/* and !*/Discussion) and define(openbugs, bugs and !link(done)) and openbugs and !link(openbugs)`
+>>
+>> Re recursion, it is avoided.. but building a pagespec that is O(N^X) where N is the
+>> number of pages in the wiki is not avoided. Probably need to add DOS prevention.
+>> --[[Joey]]
+
+>>> If you memoize the outcomes of the named pagespecs you can make in O(N.X), no?
+>>> -- [[Will]]
+
+>>>> Yeah, guess that'd work. :-)
+
+> One quick further thought. All the above discussion assumes that 'dependency' is the
+> same as 'links to', which is not really true. For example, you'd like to be able to say
+> "This bug does not depend upon [ [ link to other bug ] ]" and not have a dependency.
+> Without having different types of links, I don't see how this would be possible.
+>
+> -- [[Will]]
+
+Okie - I've had a quick attempt at this. Initial patch attached. This one doesn't quite work.
+And there is still a lot of debugging stuff in there.
+
+At the moment I've added a new preprocessor plugin, `definepagespec`, which is like
+shortcut for pagespecs. To reference a named pagespec, use `~` like this:
+
+ [ [!definepagespec name="bugs" spec="bugs/* and !*/Discussion"]]
+ [ [!definepagespec name="openbugs" spec="~bugs and !link(done)"]]
+ [ [!definepagespec name="readybugs" spec="~openbugs and !link(~openbugs)"]]
+
+At the moment the problem is in `match_link()` when we're trying to find a sub-page that
+matches the appropriate page spec. There is no good list of pages available to iterate over.
+
+ foreach my $nextpage (keys %IkiWiki::pagesources)
+
+does not give me a good list of pages. I found the same thing when I was working on
+this todo [[todo/Add_a_plugin_to_list_available_pre-processor_commands]].
+
+> I'm not sure why iterating over `%pagesources` wouldn't work here, it's the same method
+> used by anything that needs to match a pagespec against all pages..? --[[Joey]]
+
+>> My uchecked hypothesis is that %pagesources is created after the refresh hook.
+>> I've also been concerned about how globally defined pagespec shortcuts would interact with
+>> the page dependancy system. Your idea of internally defined shortcuts should fix that. -- [[Will]]
+
+>>> You're correct, the refresh hook is run very early, before pagesources
+>>> is populated. (It will be partially populated on a refresh, but will
+>>> not be updated to reflect new pages.) Agree that internally defined
+>>> seems the way to go. --[[Joey]]
+
+Immediately below is a patch which seems to basically work. Lots of debugging code is still there
+and it needs a cleanup, but I thought it worth posting at this point. (I was having problems
+with old style glob lists, so i just switched them off for the moment.)
+
+The following three inlines work for me with this patch:
+
+ Bugs:
+
+ [ [!inline pages="define(~bugs, bugs/* and ! */Discussion) and ~bugs" archive="yes"]]
+
+ OpenBugs:
+
+ [ [!inline pages="define(~bugs, bugs/* and ! */Discussion) and define(~openbugs,~bugs and !link(done)) and ~openbugs" archive="yes"]]
+
+ ReadyBugs:
+
+ [ [!inline pages="define(~bugs, bugs/* and ! */Discussion) and define(~openbugs,~bugs and !link(done)) and define(~readybugs,~openbugs and !link(~openbugs)) and ~readybugs" archive="yes"]]
+
+> Nice! Could the specfuncsref be passed in %params? I'd like to avoid
+> needing to change the prototype of every pagespec function, since several
+> plugins define them too. --[[Joey]]
+
+>> Maybe - it needs more thought. I also considered it when I was going though changing all those plugins :).
+>> My concern was that `%params` can contain other user-defined parameters,
+>> e.g. `link(target, otherparameter)`, and that means that the specFuncs could be clobbered by a user (or other
+>> weird security hole). I thought it better to separate it, but I didn't think about it too hard. I might move it to
+>> the first parameter rather than the second. Ikiwiki is my first real perl hacking and I'm still discovering
+>> good ways to write things in perl.
+>>
+>>>> `%params` contains the parameters passed to `pagespec_match`, not
+>>>> user-supplied parameters. The user-supplied parameter to a function
+>>>> like `match_glob()` or `match_link()` is passed in the second positional parameter. --[[Joey]]
+
+>>>>> OK. That seems reasonable then. The only problem is that my PERLfu is not strong enough to make it
+>>>>> work. I really have to wonder what substance was influencing the designers of PERL...
+>>>>> I can't figure out how to use the %params. And I'm pissed off enough with PERL that I'm not going
+>>>>> to try and figure it out any more. There are two patches below now. The first one uses an extra
+>>>>> argument and works. The second one tries to use %params and doesn't - take your pick :-). -- [[Will]]
+
+>> What do you think is best to do about `is_globlist()`? At the moment it requires that the 'second word', as
+>> delimited by a space and ignoring parens, is 'and' or 'or'. This doesn't hold in the above example pagespecs (so I just hard wired it to 0 to test my patch).
+>> My thought was just to search for 'and' or 'or' as words anywhere in the pagespec. Thoughts?
+
+>>> Dunno, we could just finish deprecating it. Or change the regexp to
+>>> skip over spaces in parens. (`/[^\s]+\s+([^)]+)/`) --[[Joey]]
+
+>>>> I think I have a working regexp now.
+
+>> Oh, one more thing. In pagespec_translate (now pagespec_makeperl), there is a part of the regular expression for `# any other text`.
+>> This contained `()`, which has no effect. I replaced that with `\(\)`, but that is a change in the definition of pagespecs unrelated to the
+>> rest of this patch. In a related change, commands were not able to contain `)` in their parameters. I've extended that so the cannot
+>> contain `(` or `)`. -- [[Will]]
+
+>>> `[^\s()]+` is a character class matching all characters not spaces or
+>>> parens. Since the pervious terminals in the regexp consume most
+>>> occurances of an open paren or close paren, it's unlikely for one to
+>>> get through to that part of the regexp. For example, "foo()" will be
+>>> matched by the command matcher; "(foo)" will be matched by the open
+>>> paren literal terminal. "foo(" and "foo)" can get through to the
+>>> end, and would be matched as a page name, if it didn't exclude parens.
+>>>
+>>> So why exclude them? Well, consider "foo and(bar and baz)". We don't
+>>> want it to match "and(" as a page name!
+>>>
+>>> Escaping the parens in the character class actually changes nothing; the
+>>> changed character class still matches all characters not spaces or
+>>> parens. (Try it!).
+>>>
+>>> Re commands containing '(', I don't really see any reason not to
+>>> allow that, unless it breaks something. --[[Joey]]
+
+>>>> Oh, I didn't realise you didn't need to escape parens inside []. All else I
+>>>> I understood. I have stopped commands from containing parens because
+>>>> once you allow that then you might have a extra level of depth in the parsing
+>>>> of define() statements. -- [[Will]]
+
+>>> Updated patch. Moved the specFuncsRef to the front of the arg list. Still haven't thought through the security implications of
+>>> having it in `%params`. I've also removed all the debugging `print` statements. And I've updated the `is_globlist()` function.
+>>> I think this is ready for people other than me to have a play. It is not well enough tested to commit just yet.
+>>> -- [[Will]]
+
+----
+
+diff --git a/IkiWiki.pm b/IkiWiki.pm
+index e476521..532aaf5 100644
+--- a/IkiWiki.pm
++++ b/IkiWiki.pm
+@@ -1524,7 +1524,16 @@ sub globlist_to_pagespec ($) { #{{{
+
+ sub is_globlist ($) { #{{{
+ my $s=shift;
+- return ( $s =~ /[^\s]+\s+([^\s]+)/ && $1 ne "and" && $1 ne "or" );
++ return ! ($s =~ /
++ (^\s*
++ [^\s\(]+ # single item
++ (\( # possibly with parens after it
++ ([^\)]* # with stuff inside those parens
++ (\([^\)]*\))*)* # maybe even nested parens
++ \))?\s*$
++ ) |
++ (\s and \s) | (\s or \s) # or we find 'and' or 'or' somewhere
++ /x);
+ } #}}}
+
+ sub safequote ($) { #{{{
+@@ -1605,7 +1614,7 @@ sub pagespec_merge ($$) { #{{{
+ return "($a) or ($b)";
+ } #}}}
+
+-sub pagespec_translate ($) { #{{{
++sub pagespec_makeperl ($) { #{{{
+ my $spec=shift;
+
+ # Support for old-style GlobLists.
+@@ -1624,9 +1633,11 @@ sub pagespec_translate ($) { #{{{
+ |
+ \) # )
+ |
+- \w+\([^\)]*\) # command(params)
++ define\(\s*~\w+\s*,((\([^\(\)]*\)) | ([^\(\)]+))+\) # define(~specName, spec) - spec can contain parens 1 deep
++ |
++ \w+\([^\(\)]*\) # command(params) - params cannot contain parens
+ |
+- [^\s()]+ # any other text
++ [^\s\(\)]+ # any other text
+ )
+ \s* # ignore whitespace
+ }igx) {
+@@ -1640,16 +1651,23 @@ sub pagespec_translate ($) { #{{{
+ elsif ($word eq "(" || $word eq ")" || $word eq "!") {
+ $code.=' '.$word;
+ }
++ elsif ($word =~ /^define\(\s*~(\w+)\s*,(.*)\)$/) {
++ $code .= " (\$specFuncsRef->{$1}=";
++ $code .= "memoize(";
++ $code .= &pagespec_makeperl($2);
++ $code .= ")";
++ $code .= ") ";
++ }
+ elsif ($word =~ /^(\w+)\((.*)\)$/) {
+ if (exists $IkiWiki::PageSpec::{"match_$1"}) {
+- $code.="IkiWiki::PageSpec::match_$1(\$page, ".safequote($2).", \@_)";
++ $code.="IkiWiki::PageSpec::match_$1(\$specFuncsRef, \$page, ".safequote($2).", \@_)";
+ }
+ else {
+ $code.=' 0';
+ }
+ }
+ else {
+- $code.=" IkiWiki::PageSpec::match_glob(\$page, ".safequote($word).", \@_)";
++ $code.=" IkiWiki::PageSpec::match_glob(\$specFuncsRef, \$page, ".safequote($word).", \@_)";
+ }
+ }
+
+@@ -1657,8 +1675,16 @@ sub pagespec_translate ($) { #{{{
+ $code=0;
+ }
+
++ return 'sub { my $specFuncsRef=shift; my $page=shift; '.$code.' }';
++} #}}}
++
++sub pagespec_translate ($) { #{{{
++ my $spec=shift;
++
++ my $code = pagespec_makeperl($spec);
++
+ no warnings;
+- return eval 'sub { my $page=shift; '.$code.' }';
++ return eval $code;
+ } #}}}
+
+ sub pagespec_match ($$;@) { #{{{
+@@ -1673,7 +1699,7 @@ sub pagespec_match ($$;@) { #{{{
+
+ my $sub=pagespec_translate($spec);
+ return IkiWiki::FailReason->new("syntax error in pagespec \"$spec\"") if $@;
+- return $sub->($page, @params);
++ return $sub->({}, $page, @params);
+ } #}}}
+
+ sub pagespec_valid ($) { #{{{
+@@ -1722,11 +1748,71 @@ sub new { #{{{
+
+ package IkiWiki::PageSpec;
+
+-sub match_glob ($$;@) { #{{{
++sub check_named_spec($$$;@) {
++ my $specFuncsRef=shift;
++ my $page=shift;
++ my $specName=shift;
++ my %params=@_;
++
++ return IkiWiki::FailReason->new("Named page spec '$specName' is not valid")
++ unless (substr($specName, 0, 1) eq '~');
++
++ $specName = substr($specName, 1);
++
++ if (exists $specFuncsRef->{$specName}) {
++ # remove the named spec from the spec refs
++ # when we recurse to avoid infinite recursion
++ my $sub = $specFuncsRef->{$specName};
++ $specFuncsRef->{$specName} = undef;
++ my $result = $sub->($specFuncsRef, $page, %params);
++ $specFuncsRef->{$specName} = $sub;
++ return $result;
++ } else {
++ return IkiWiki::FailReason->new("Page spec '$specName' does not exist");
++ }
++}
++
++sub check_named_spec_existential($$$$;@) {
++ my $specFuncsRef=shift;
++ my $page=shift;
++ my $specName=shift;
++ my $funcref=shift;
++ my %params=@_;
++
++ return IkiWiki::FailReason->new("Named page spec '$specName' is not valid")
++ unless (substr($specName, 0, 1) eq '~');
++ $specName = substr($specName, 1);
++
++ if (exists $specFuncsRef->{$specName}) {
++ # remove the named spec from the spec refs
++ # when we recurse to avoid infinite recursion
++ my $sub = $specFuncsRef->{$specName};
++ $specFuncsRef->{$specName} = undef;
++
++ foreach my $nextpage (keys %IkiWiki::pagesources) {
++ if ($sub->($specFuncsRef, $nextpage, %params)) {
++ my $tempResult = $funcref->($specFuncsRef, $page, $nextpage, %params);
++ return $tempResult if ($tempResult);
++ }
++ }
++
++ $specFuncsRef->{$specName} = $sub;
++ return IkiWiki::FailReason->new("No page in spec '$specName' was successfully matched");
++ } else {
++ return IkiWiki::FailReason->new("Named page spec '$specName' does not exist");
++ }
++}
++
++sub match_glob ($$$;@) { #{{{
++ my $specFuncsRef=shift;
+ my $page=shift;
+ my $glob=shift;
+ my %params=@_;
+
++ if (substr($glob, 0, 1) eq '~') {
++ return check_named_spec($specFuncsRef, $page, $glob);
++ }
++
+ my $from=exists $params{location} ? $params{location} : '';
+
+ # relative matching
+@@ -1750,17 +1836,23 @@ sub match_glob ($$;@) { #{{{
+ }
+ } #}}}
+
+-sub match_internal ($$;@) { #{{{
+- return match_glob($_[0], $_[1], @_, internal => 1)
++sub match_internal ($$$;@) { #{{{
++ return match_glob(shift, shift, shift, @_, internal => 1)
+ } #}}}
+
+-sub match_link ($$;@) { #{{{
++sub match_link ($$$;@) { #{{{
++ my $specFuncsRef=shift;
+ my $page=shift;
+- my $link=lc(shift);
++ my $fulllink=shift;
++ my $link=lc($fulllink);
+ my %params=@_;
+
+- my $from=exists $params{location} ? $params{location} : '';
++ if (substr($fulllink, 0, 1) eq '~') {
++ return check_named_spec_existential($specFuncsRef, $page, $fulllink, \&match_link);
++ }
+
++ my $from=exists $params{location} ? $params{location} : '';
++
+ # relative matching
+ if ($link =~ m!^\.! && defined $from) {
+ $from=~s#/?[^/]+$##;
+@@ -1778,17 +1870,21 @@ sub match_link ($$;@) { #{{{
+ }
+ else {
+ return IkiWiki::SuccessReason->new("$page links to page $p matching $link")
+- if match_glob($p, $link, %params);
++ if match_glob($specFuncsRef, $p, $link, %params);
+ }
+ }
+ return IkiWiki::FailReason->new("$page does not link to $link");
+ } #}}}
+
+-sub match_backlink ($$;@) { #{{{
+- return match_link($_[1], $_[0], @_);
++sub match_backlink ($$$;@) { #{{{
++ my $specFuncsRef=shift;
++ my $page=shift;
++ my $backlink=shift;
++ return match_link($specFuncsRef, $backlink, $page, @_);
+ } #}}}
+
+-sub match_created_before ($$;@) { #{{{
++sub match_created_before ($$$;@) { #{{{
++ my $specFuncsRef=shift;
+ my $page=shift;
+ my $testpage=shift;
+
+@@ -1805,7 +1901,8 @@ sub match_created_before ($$;@) { #{{{
+ }
+ } #}}}
+
+-sub match_created_after ($$;@) { #{{{
++sub match_created_after ($$$;@) { #{{{
++ my $specFuncsRef=shift;
+ my $page=shift;
+ my $testpage=shift;
+
+@@ -1822,8 +1919,12 @@ sub match_created_after ($$;@) { #{{{
+ }
+ } #}}}
+
+-sub match_creation_day ($$;@) { #{{{
+- if ((gmtime($IkiWiki::pagectime{shift()}))[3] == shift) {
++sub match_creation_day ($$$;@) { #{{{
++ shift;
++ my $page=shift;
++ my $time=shift;
++
++ if ((gmtime($IkiWiki::pagectime{$page}))[3] == $time) {
+ return IkiWiki::SuccessReason->new('creation_day matched');
+ }
+ else {
+@@ -1831,8 +1932,12 @@ sub match_creation_day ($$;@) { #{{{
+ }
+ } #}}}
+
+-sub match_creation_month ($$;@) { #{{{
+- if ((gmtime($IkiWiki::pagectime{shift()}))[4] + 1 == shift) {
++sub match_creation_month ($$$;@) { #{{{
++ shift;
++ my $page=shift;
++ my $time=shift;
++
++ if ((gmtime($IkiWiki::pagectime{$page}))[4] + 1 == $time) {
+ return IkiWiki::SuccessReason->new('creation_month matched');
+ }
+ else {
+@@ -1840,8 +1945,12 @@ sub match_creation_month ($$;@) { #{{{
+ }
+ } #}}}
+
+-sub match_creation_year ($$;@) { #{{{
+- if ((gmtime($IkiWiki::pagectime{shift()}))[5] + 1900 == shift) {
++sub match_creation_year ($$$;@) { #{{{
++ shift;
++ my $page=shift;
++ my $time=shift;
++
++ if ((gmtime($IkiWiki::pagectime{$page}))[5] + 1900 == $time) {
+ return IkiWiki::SuccessReason->new('creation_year matched');
+ }
+ else {
+diff --git a/IkiWiki/Plugin/attachment.pm b/IkiWiki/Plugin/attachment.pm
+index f1f792a..a410e48 100644
+--- a/IkiWiki/Plugin/attachment.pm
++++ b/IkiWiki/Plugin/attachment.pm
+@@ -291,7 +291,8 @@ sub attachment_list ($) { #{{{
+
+ package IkiWiki::PageSpec;
+
+-sub match_user ($$;@) { #{{{
++sub match_user ($$$;@) { #{{{
++ shift;
+ shift;
+ my $user=shift;
+ my %params=@_;
+@@ -311,7 +312,8 @@ sub match_user ($$;@) { #{{{
+ }
+ } #}}}
+
+-sub match_ip ($$;@) { #{{{
++sub match_ip ($$$;@) { #{{{
++ shift;
+ shift;
+ my $ip=shift;
+ my %params=@_;
+diff --git a/IkiWiki/Plugin/conditional.pm b/IkiWiki/Plugin/conditional.pm
+index 7716fce..c0dbb50 100644
+--- a/IkiWiki/Plugin/conditional.pm
++++ b/IkiWiki/Plugin/conditional.pm
+@@ -70,7 +70,8 @@ sub preprocess_if (@) { #{{{
+
+ package IkiWiki::PageSpec;
+
+-sub match_enabled ($$;@) { #{{{
++sub match_enabled ($$$;@) { #{{{
++ shift;
+ shift;
+ my $plugin=shift;
+
+@@ -83,13 +84,14 @@ sub match_enabled ($$;@) { #{{{
+ }
+ } #}}}
+
+-sub match_sourcepage ($$;@) { #{{{
++sub match_sourcepage ($$$;@) { #{{{
++ my $specFuncsRef=shift;
+ shift;
+ my $glob=shift;
+ my %params=@_;
+
+ return IkiWiki::FailReason->new("cannot match sourcepage") unless exists $params{sourcepage};
+- if (match_glob($params{sourcepage}, $glob, @_)) {
++ if (match_glob($specFuncsRef, $params{sourcepage}, $glob, @_)) {
+ return IkiWiki::SuccessReason->new("sourcepage matches $glob");
+ }
+ else {
+@@ -97,13 +99,14 @@ sub match_sourcepage ($$;@) { #{{{
+ }
+ } #}}}
+
+-sub match_destpage ($$;@) { #{{{
++sub match_destpage ($$$;@) { #{{{
++ my $specFuncsRef=shift;
+ shift;
+ my $glob=shift;
+ my %params=@_;
+
+ return IkiWiki::FailReason->new("cannot match destpage") unless exists $params{destpage};
+- if (match_glob($params{destpage}, $glob, @_)) {
++ if (match_glob($specFuncsRef, $params{destpage}, $glob, @_)) {
+ return IkiWiki::SuccessReason->new("destpage matches $glob");
+ }
+ else {
+@@ -111,7 +114,8 @@ sub match_destpage ($$;@) { #{{{
+ }
+ } #}}}
+
+-sub match_included ($$;@) { #{{{
++sub match_included ($$$;@) { #{{{
++ shift;
+ shift;
+ shift;
+ my %params=@_;
+diff --git a/IkiWiki/Plugin/filecheck.pm b/IkiWiki/Plugin/filecheck.pm
+index 6f71be3..3592342 100644
+--- a/IkiWiki/Plugin/filecheck.pm
++++ b/IkiWiki/Plugin/filecheck.pm
+@@ -66,7 +66,8 @@ sub humansize ($) { #{{{
+
+ package IkiWiki::PageSpec;
+
+-sub match_maxsize ($$;@) { #{{{
++sub match_maxsize ($$$;@) { #{{{
++ shift;
+ my $page=shift;
+ my $maxsize=eval{IkiWiki::Plugin::attachment::parsesize(shift)};
+ if ($@) {
+@@ -87,7 +88,8 @@ sub match_maxsize ($$;@) { #{{{
+ }
+ } #}}}
+
+-sub match_minsize ($$;@) { #{{{
++sub match_minsize ($$$;@) { #{{{
++ shift;
+ my $page=shift;
+ my $minsize=eval{IkiWiki::Plugin::attachment::parsesize(shift)};
+ if ($@) {
+@@ -108,7 +110,8 @@ sub match_minsize ($$;@) { #{{{
+ }
+ } #}}}
+
+-sub match_mimetype ($$;@) { #{{{
++sub match_mimetype ($$$;@) { #{{{
++ shift;
+ my $page=shift;
+ my $wanted=shift;
+
+@@ -138,7 +141,8 @@ sub match_mimetype ($$;@) { #{{{
+ }
+ } #}}}
+
+-sub match_virusfree ($$;@) { #{{{
++sub match_virusfree ($$$;@) { #{{{
++ shift;
+ my $page=shift;
+ my $wanted=shift;
+
+@@ -180,7 +184,7 @@ sub match_virusfree ($$;@) { #{{{
+ }
+ } #}}}
+
+-sub match_ispage ($$;@) { #{{{
++sub match_ispage ($$$;@) { #{{{
+ my $filename=shift;
+
+ if (defined IkiWiki::pagetype($filename)) {
+diff --git a/IkiWiki/Plugin/meta.pm b/IkiWiki/Plugin/meta.pm
+index b2c85c8..788f248 100644
+--- a/IkiWiki/Plugin/meta.pm
++++ b/IkiWiki/Plugin/meta.pm
+@@ -263,6 +263,7 @@ sub pagetemplate (@) { #{{{
+
+ sub match { #{{{
+ my $field=shift;
++ shift;
+ my $page=shift;
+
+ # turn glob into a safe regexp
+@@ -291,23 +292,23 @@ sub match { #{{{
+
+ package IkiWiki::PageSpec;
+
+-sub match_title ($$;@) { #{{{
++sub match_title ($$$;@) { #{{{
+ IkiWiki::Plugin::meta::match("title", @_);
+ } #}}}
+
+-sub match_author ($$;@) { #{{{
++sub match_author ($$$;@) { #{{{
+ IkiWiki::Plugin::meta::match("author", @_);
+ } #}}}
+
+-sub match_authorurl ($$;@) { #{{{
++sub match_authorurl ($$$;@) { #{{{
+ IkiWiki::Plugin::meta::match("authorurl", @_);
+ } #}}}
+
+-sub match_license ($$;@) { #{{{
++sub match_license ($$$;@) { #{{{
+ IkiWiki::Plugin::meta::match("license", @_);
+ } #}}}
+
+-sub match_copyright ($$;@) { #{{{
++sub match_copyright ($$$;@) { #{{{
+ IkiWiki::Plugin::meta::match("copyright", @_);
+ } #}}}
+
+----
+
+diff --git a/IkiWiki.pm b/IkiWiki.pm
+index e476521..0751d56 100644
+--- a/IkiWiki.pm
++++ b/IkiWiki.pm
+@@ -1524,7 +1524,16 @@ sub globlist_to_pagespec ($) { #{{{
+
+ sub is_globlist ($) { #{{{
+ my $s=shift;
+- return ( $s =~ /[^\s]+\s+([^\s]+)/ && $1 ne "and" && $1 ne "or" );
++ return ! ($s =~ /
++ (^\s*
++ [^\s(]+ # single item
++ (\( # possibly with parens after it
++ ([^)]* # with stuff inside those parens
++ (\([^)]*\))*)* # maybe even nested parens
++ \))?\s*$
++ ) |
++ (\s and \s) | (\s or \s) # or we find 'and' or 'or' somewhere
++ /x);
+ } #}}}
+
+ sub safequote ($) { #{{{
+@@ -1605,7 +1614,7 @@ sub pagespec_merge ($$) { #{{{
+ return "($a) or ($b)";
+ } #}}}
+
+-sub pagespec_translate ($) { #{{{
++sub pagespec_makeperl ($) { #{{{
+ my $spec=shift;
+
+ # Support for old-style GlobLists.
+@@ -1624,7 +1633,9 @@ sub pagespec_translate ($) { #{{{
+ |
+ \) # )
+ |
+- \w+\([^\)]*\) # command(params)
++ define\(\s*~\w+\s*,((\([^()]*\)) | ([^()]+))+\) # define(~specName, spec) - spec can contain parens 1 deep
++ |
++ \w+\([^()]*\) # command(params) - params cannot contain parens
+ |
+ [^\s()]+ # any other text
+ )
+@@ -1640,16 +1651,23 @@ sub pagespec_translate ($) { #{{{
+ elsif ($word eq "(" || $word eq ")" || $word eq "!") {
+ $code.=' '.$word;
+ }
++ elsif ($word =~ /^define\(\s*~(\w+)\s*,(.*)\)$/) {
++ $code .= " (\$params{specFuncs}->{$1}="; # (exists \$params{specFuncs}) &&
++ $code .= "memoize(";
++ $code .= &pagespec_makeperl($2);
++ $code .= ")";
++ $code .= ") ";
++ }
+ elsif ($word =~ /^(\w+)\((.*)\)$/) {
+ if (exists $IkiWiki::PageSpec::{"match_$1"}) {
+- $code.="IkiWiki::PageSpec::match_$1(\$page, ".safequote($2).", \@_)";
++ $code.="IkiWiki::PageSpec::match_$1(\$page, ".safequote($2).", \%params)";
+ }
+ else {
+ $code.=' 0';
+ }
+ }
+ else {
+- $code.=" IkiWiki::PageSpec::match_glob(\$page, ".safequote($word).", \@_)";
++ $code.=" IkiWiki::PageSpec::match_glob(\$page, ".safequote($word).", \%params)";
+ }
+ }
+
+@@ -1657,23 +1675,36 @@ sub pagespec_translate ($) { #{{{
+ $code=0;
+ }
+
++ return 'sub { my $page=shift; my %params = @_; '.$code.' }';
++} #}}}
++
++sub pagespec_translate ($) { #{{{
++ my $spec=shift;
++
++ my $code = pagespec_makeperl($spec);
++
++ print "Spec '$spec' generated code '$code'\n";
++
+ no warnings;
+- return eval 'sub { my $page=shift; '.$code.' }';
++ return eval $code;
+ } #}}}
+
+ sub pagespec_match ($$;@) { #{{{
+ my $page=shift;
+ my $spec=shift;
+ my @params=@_;
++ my %params=@_;
+
+ # Backwards compatability with old calling convention.
+ if (@params == 1) {
+- unshift @params, 'location';
++ %params = { location => $params[1] };
+ }
+
++ $params{specFuncs} = {} unless exists $params{specFuncs};
++
+ my $sub=pagespec_translate($spec);
+ return IkiWiki::FailReason->new("syntax error in pagespec \"$spec\"") if $@;
+- return $sub->($page, @params);
++ return $sub->($page, %params);
+ } #}}}
+
+ sub pagespec_valid ($) { #{{{
+@@ -1722,11 +1753,84 @@ sub new { #{{{
+
+ package IkiWiki::PageSpec;
+
++sub check_named_spec($$;@) {
++ my $page=shift;
++ my $specName=shift;
++ my %params=@_;
++
++ print "Checking named spec $specName\n";
++
++ error("Unable to find specFuncs in params to check_named_spec()!") unless exists $params{specFuncs};
++ my $specFuncsRef=$params{specFuncs};
++
++ print "A\n";
++
++ return IkiWiki::FailReason->new("Named page spec '$specName' is not valid")
++ unless (substr($specName, 0, 1) eq '~');
++
++ $specName = substr($specName, 1);
++
++ if (exists $specFuncsRef->{$specName}) {
++ # remove the named spec from the spec refs
++ # when we recurse to avoid infinite recursion
++ my $sub = $specFuncsRef->{$specName};
++ $specFuncsRef->{$specName} = undef;
++ my $result = $sub->($specFuncsRef, $page, %params);
++ $specFuncsRef->{$specName} = $sub;
++ return $result;
++ } else {
++ print "Invalid specname\n";
++ return IkiWiki::FailReason->new("Page spec '$specName' does not exist");
++ }
++}
++
++sub check_named_spec_existential($$$;@) {
++ my $page=shift;
++ my $specName=shift;
++ my $funcref=shift;
++ my %params=@_;
++
++ print "(Existential) Checking named spec $specName\n";
++
++ error("Unable to find specFuncs in params to check_named_spec()!") unless exists $params{specFuncs};
++ my $specFuncsRef=$params{specFuncs};
++
++ print "B\n";
++
++ return IkiWiki::FailReason->new("Named page spec '$specName' is not valid")
++ unless (substr($specName, 0, 1) eq '~');
++ $specName = substr($specName, 1);
++
++ if (exists $specFuncsRef->{$specName}) {
++ # remove the named spec from the spec refs
++ # when we recurse to avoid infinite recursion
++ my $sub = $specFuncsRef->{$specName};
++ $specFuncsRef->{$specName} = undef;
++
++ foreach my $nextpage (keys %IkiWiki::pagesources) {
++ if ($sub->($specFuncsRef, $nextpage, %params)) {
++ my $tempResult = $funcref->($page, $nextpage, %params);
++ return $tempResult if ($tempResult);
++ }
++ }
++
++ $specFuncsRef->{$specName} = $sub;
++ return IkiWiki::FailReason->new("No page in spec '$specName' was successfully matched");
++ } else {
++ print "Invalid specname\n";
++ return IkiWiki::FailReason->new("Named page spec '$specName' does not exist");
++ }
++}
++
+ sub match_glob ($$;@) { #{{{
+ my $page=shift;
+ my $glob=shift;
+ my %params=@_;
+
++ if (substr($glob, 0, 1) eq '~') {
++ return check_named_spec($page, $glob, %params);
++ }
++
+ my $from=exists $params{location} ? $params{location} : '';
+
+ # relative matching
+@@ -1756,11 +1860,16 @@ sub match_internal ($$;@) { #{{{
+
+ sub match_link ($$;@) { #{{{
+ my $page=shift;
+- my $link=lc(shift);
++ my $fulllink=shift;
++ my $link=lc($fulllink);
+ my %params=@_;
+
+- my $from=exists $params{location} ? $params{location} : '';
++ if (substr($fulllink, 0, 1) eq '~') {
++ return check_named_spec_existential($page, $fulllink, \&match_link, %params);
++ }
+
++ my $from=exists $params{location} ? $params{location} : '';
++
+ # relative matching
+ if ($link =~ m!^\.! && defined $from) {
+ $from=~s#/?[^/]+$##;
+@@ -1785,12 +1894,25 @@ sub match_link ($$;@) { #{{{
+ } #}}}
+
+ sub match_backlink ($$;@) { #{{{
+- return match_link($_[1], $_[0], @_);
++ my $page=shift;
++ my $backlink=shift;
++ my %params=@_;
++
++ if (substr($backlink, 0, 1) eq '~') {
++ return check_named_spec_existential($page, $backlink, \&match_backlink, %params);
++ }
++
++ return match_link($backlink, $page, %params);
+ } #}}}
+
+ sub match_created_before ($$;@) { #{{{
+ my $page=shift;
+ my $testpage=shift;
++ my %params=@_;
++
++ if (substr($testpage, 0, 1) eq '~') {
++ return check_named_spec_existential($page, $testpage, \&match_created_before, %params);
++ }
+
+ if (exists $IkiWiki::pagectime{$testpage}) {
+ if ($IkiWiki::pagectime{$page} < $IkiWiki::pagectime{$testpage}) {
+@@ -1808,6 +1930,11 @@ sub match_created_before ($$;@) { #{{{
+ sub match_created_after ($$;@) { #{{{
+ my $page=shift;
+ my $testpage=shift;
++ my %params=@_;
++
++ if (substr($testpage, 0, 1) eq '~') {
++ return check_named_spec_existential($page, $testpage, \&match_created_after, %params);
++ }
+
+ if (exists $IkiWiki::pagectime{$testpage}) {
+ if ($IkiWiki::pagectime{$page} > $IkiWiki::pagectime{$testpage}) {