1 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]]
3 > I started having a think about this. I'm going to start with the idea that expanding
4 > the pagespec syntax is the way to attack this. It seems that any pagespec that is going
5 > to represent "all bugs with no dependencies on bugs not marked as done" is going to
6 > need some way to represent "bugs not marked as done" as a collection of pages, and
7 > then represent "bugs which do not link to pages in the previous collection".
9 > One way to do this would be to introduce variables into the pagespec, along with
10 > universal and/or existential [[!wikipedia Quantification]]. That looks quite complex.
12 >> I thought about this briefly, and got about that far.. glad you got
13 >> further. :-) --[[Joey]]
15 >> Or, one could also refer to the language of [[!wikipedia description logics]]: their formulas actually define classes of objects through quantified relations to other classes. --Ivan Z.
17 > Another option would be go with a more functional syntax. The concept here would
18 > be to allow a pagespec to appear in a 'pagespec function' anywhere a page can. e.g.
19 > I could pass a pagespec to `link()` and that would return true if there is a link to any
20 > page matching the pagespec. This makes the variables and existential quantification
21 > implicit. It would allow the example requested above:
23 >> `bugs/* and !*/Discussion and !link(bugs/* and !*/Discussion and !link(done))`
25 > Unfortunately, this is also going to make the pagespec parsing more complex because
26 > we now need to parse nested sets of parentheses to know when the nested pagespec
27 > ends, and that isn't a regular language (we can't use regular expression matching for
30 >> Also, it may cause ambiguities with page names that contain parens
31 >> (though some such ambigutities already exist with the pagespec syntax).
33 > One simplification of that would be to introduce some pagespec [[shortcuts]]. We could
34 > then allow pagespec functions to take either pages, or named pagespec shortcuts. The
35 > pagespec shortcuts would just be listed on a special page, like current [[shortcuts]].
36 > (It would probably be a good idea to require that shortcuts on that page can only refer
37 > to named pagespecs higher up that page than themselves. That would stop some
38 > looping issues...) These shortcuts would be used as follows: when trying to match
39 > a page (without globs) you look to see if the page exists. If it does then you have a
40 > match. If it doesn't, then you look to see if a similarly named pagespec shortcut
41 > exists. If it does, then you check that pagespec recursively to see if you have a match.
42 > The ordering requirement on named pagespecs stops infinite recursion.
44 > Does that seem like a reasonable first approach?
48 >> Having a separate page for the shortcuts feels unwieldly.. perhaps
49 >> instead the shortcut could be defined earlier in the scope of the same
50 >> pagespec that uses it?
52 >> Example: `define(~bugs, bugs/* and !*/Discussion) and define(~openbugs, ~bugs and !link(done)) and ~openbugs and !link(~openbugs)`
54 >>> That could work. parens are only ever nested 1 deep in that grammar so it is regular and the current parsing would be ok.
56 >> Note that I made the "~" explicit, not implicit, so it could be left out. In the case of ambiguity between
57 >> a definition and a page name, the definition would win.
59 >>> 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.
61 >> So, equivilant example: `define(bugs, bugs/* and !*/Discussion) and define(openbugs, bugs and !link(done)) and openbugs and !link(openbugs)`
63 >> Re recursion, it is avoided.. but building a pagespec that is O(N^X) where N is the
64 >> number of pages in the wiki is not avoided. Probably need to add DOS prevention.
67 >>> If you memoize the outcomes of the named pagespecs you can make in O(N.X), no?
70 >>>> Yeah, guess that'd work. :-)
72 > <a id="another_kind_of_links" />One quick further thought. All the above discussion assumes that 'dependency' is the
73 > same as 'links to', which is not really true. For example, you'd like to be able to say
74 > "This bug does not depend upon [ [ link to other bug ] ]" and not have a dependency.
75 > Without having different types of links, I don't see how this would be possible.
79 >> I saw that this issue is targeted at by the work on [[structured page data#another_kind_of_links]]. --Ivan Z.
81 Okie - I've had a quick attempt at this. Initial patch attached. This one doesn't quite work.
82 And there is still a lot of debugging stuff in there.
84 At the moment I've added a new preprocessor plugin, `definepagespec`, which is like
85 shortcut for pagespecs. To reference a named pagespec, use `~` like this:
87 [ [!definepagespec name="bugs" spec="bugs/* and !*/Discussion"]]
88 [ [!definepagespec name="openbugs" spec="~bugs and !link(done)"]]
89 [ [!definepagespec name="readybugs" spec="~openbugs and !link(~openbugs)"]]
91 At the moment the problem is in `match_link()` when we're trying to find a sub-page that
92 matches the appropriate page spec. There is no good list of pages available to iterate over.
94 foreach my $nextpage (keys %IkiWiki::pagesources)
96 does not give me a good list of pages. I found the same thing when I was working on
97 this todo [[todo/Add_a_plugin_to_list_available_pre-processor_commands]].
99 > I'm not sure why iterating over `%pagesources` wouldn't work here, it's the same method
100 > used by anything that needs to match a pagespec against all pages..? --[[Joey]]
102 >> My uchecked hypothesis is that %pagesources is created after the refresh hook.
103 >> I've also been concerned about how globally defined pagespec shortcuts would interact with
104 >> the page dependancy system. Your idea of internally defined shortcuts should fix that. -- [[Will]]
106 >>> You're correct, the refresh hook is run very early, before pagesources
107 >>> is populated. (It will be partially populated on a refresh, but will
108 >>> not be updated to reflect new pages.) Agree that internally defined
109 >>> seems the way to go. --[[Joey]]
111 Immediately below is a patch which seems to basically work. Lots of debugging code is still there
112 and it needs a cleanup, but I thought it worth posting at this point. (I was having problems
113 with old style glob lists, so i just switched them off for the moment.)
115 The following three inlines work for me with this patch:
119 [ [!inline pages="define(~bugs, bugs/* and ! */Discussion) and ~bugs" archive="yes"]]
123 [ [!inline pages="define(~bugs, bugs/* and ! */Discussion) and define(~openbugs,~bugs and !link(done)) and ~openbugs" archive="yes"]]
127 [ [!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"]]
129 > Nice! Could the specfuncsref be passed in %params? I'd like to avoid
130 > needing to change the prototype of every pagespec function, since several
131 > plugins define them too. --[[Joey]]
133 >> Maybe - it needs more thought. I also considered it when I was going though changing all those plugins :).
134 >> My concern was that `%params` can contain other user-defined parameters,
135 >> e.g. `link(target, otherparameter)`, and that means that the specFuncs could be clobbered by a user (or other
136 >> weird security hole). I thought it better to separate it, but I didn't think about it too hard. I might move it to
137 >> the first parameter rather than the second. Ikiwiki is my first real perl hacking and I'm still discovering
138 >> good ways to write things in perl.
140 >>>> `%params` contains the parameters passed to `pagespec_match`, not
141 >>>> user-supplied parameters. The user-supplied parameter to a function
142 >>>> like `match_glob()` or `match_link()` is passed in the second positional parameter. --[[Joey]]
144 >>>>> OK. That seems reasonable then. The only problem is that my PERLfu is not strong enough to make it
145 >>>>> work. I really have to wonder what substance was influencing the designers of PERL...
146 >>>>> I can't figure out how to use the %params. And I'm pissed off enough with PERL that I'm not going
147 >>>>> to try and figure it out any more. There are two patches below now. The first one uses an extra
148 >>>>> argument and works. The second one tries to use %params and doesn't - take your pick :-). -- [[Will]]
150 >> What do you think is best to do about `is_globlist()`? At the moment it requires that the 'second word', as
151 >> 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).
152 >> My thought was just to search for 'and' or 'or' as words anywhere in the pagespec. Thoughts?
154 >>> Dunno, we could just finish deprecating it. Or change the regexp to
155 >>> skip over spaces in parens. (`/[^\s]+\s+([^)]+)/`) --[[Joey]]
157 >>>> I think I have a working regexp now.
159 >> Oh, one more thing. In pagespec_translate (now pagespec_makeperl), there is a part of the regular expression for `# any other text`.
160 >> This contained `()`, which has no effect. I replaced that with `\(\)`, but that is a change in the definition of pagespecs unrelated to the
161 >> rest of this patch. In a related change, commands were not able to contain `)` in their parameters. I've extended that so the cannot
162 >> contain `(` or `)`. -- [[Will]]
164 >>> `[^\s()]+` is a character class matching all characters not spaces or
165 >>> parens. Since the pervious terminals in the regexp consume most
166 >>> occurances of an open paren or close paren, it's unlikely for one to
167 >>> get through to that part of the regexp. For example, "foo()" will be
168 >>> matched by the command matcher; "(foo)" will be matched by the open
169 >>> paren literal terminal. "foo(" and "foo)" can get through to the
170 >>> end, and would be matched as a page name, if it didn't exclude parens.
172 >>> So why exclude them? Well, consider "foo and(bar and baz)". We don't
173 >>> want it to match "and(" as a page name!
175 >>> Escaping the parens in the character class actually changes nothing; the
176 >>> changed character class still matches all characters not spaces or
177 >>> parens. (Try it!).
179 >>> Re commands containing '(', I don't really see any reason not to
180 >>> allow that, unless it breaks something. --[[Joey]]
182 >>>> Oh, I didn't realise you didn't need to escape parens inside []. All else I
183 >>>> I understood. I have stopped commands from containing parens because
184 >>>> once you allow that then you might have a extra level of depth in the parsing
185 >>>> of define() statements. -- [[Will]]
187 >>> Updated patch. Moved the specFuncsRef to the front of the arg list. Still haven't thought through the security implications of
188 >>> having it in `%params`. I've also removed all the debugging `print` statements. And I've updated the `is_globlist()` function.
189 >>> I think this is ready for people other than me to have a play. It is not well enough tested to commit just yet.
192 I've lost track of the indent level, so I'm going back to not indented - I think this is a working [[patch]] taking into
193 account all comments above (which doesn't mean it is above reproach :) ). --[[Will]]
197 diff --git a/IkiWiki.pm b/IkiWiki.pm
198 index 4e4da11..8b3cdfe 100644
201 @@ -1550,7 +1550,16 @@ sub globlist_to_pagespec ($) {
203 sub is_globlist ($) {
205 - return ( $s =~ /[^\s]+\s+([^\s]+)/ && $1 ne "and" && $1 ne "or" );
208 + [^\s(]+ # single item
209 + (\( # possibly with parens after it
210 + ([^)]* # with stuff inside those parens
211 + (\([^)]*\))*)* # maybe even nested parens
214 + (\s and \s) | (\s or \s) # or we find 'and' or 'or' somewhere
219 @@ -1631,7 +1640,7 @@ sub pagespec_merge ($$) {
220 return "($a) or ($b)";
223 -sub pagespec_translate ($) {
224 +sub pagespec_makeperl ($) {
227 # Support for old-style GlobLists.
228 @@ -1650,12 +1659,14 @@ sub pagespec_translate ($) {
232 - \w+\([^\)]*\) # command(params)
233 + define\(\s*~\w+\s*,((\([^()]*\)) | ([^()]+))+\) # define(~specName, spec) - spec can contain parens 1 deep
235 + \w+\([^()]*\) # command(params) - params cannot contain parens
237 [^\s()]+ # any other text
239 \s* # ignore whitespace
243 if (lc $word eq 'and') {
245 @@ -1666,16 +1677,23 @@ sub pagespec_translate ($) {
246 elsif ($word eq "(" || $word eq ")" || $word eq "!") {
249 - elsif ($word =~ /^(\w+)\((.*)\)$/) {
250 + elsif ($word =~ /^define\(\s*~(\w+)\s*,(.*)\)$/s) {
251 + $code .= " (\$params{specFuncs}->{$1}="; # (exists \$params{specFuncs}) &&
252 + $code .= "memoize(";
253 + $code .= &pagespec_makeperl($2);
257 + elsif ($word =~ /^(\w+)\((.*)\)$/s) {
258 if (exists $IkiWiki::PageSpec::{"match_$1"}) {
259 - $code.="IkiWiki::PageSpec::match_$1(\$page, ".safequote($2).", \@_)";
260 + $code.="IkiWiki::PageSpec::match_$1(\$page, ".safequote($2).", \%params)";
267 - $code.=" IkiWiki::PageSpec::match_glob(\$page, ".safequote($word).", \@_)";
268 + $code.=" IkiWiki::PageSpec::match_glob(\$page, ".safequote($word).", \%params)";
272 @@ -1683,8 +1701,18 @@ sub pagespec_translate ($) {
276 + return 'sub { my $page=shift; my %params = @_; '.$code.' }';
279 +sub pagespec_translate ($) {
282 + my $code = pagespec_makeperl($spec);
284 + # print STDERR "Spec '$spec' generated code '$code'\n";
287 - return eval 'sub { my $page=shift; '.$code.' }';
291 sub pagespec_match ($$;@) {
292 @@ -1699,7 +1727,7 @@ sub pagespec_match ($$;@) {
294 my $sub=pagespec_translate($spec);
295 return IkiWiki::FailReason->new("syntax error in pagespec \"$spec\"") if $@;
296 - return $sub->($page, @params);
297 + return $sub->($page, @params, specFuncs => {});
300 sub pagespec_valid ($) {
301 @@ -1748,11 +1776,78 @@ sub new {
303 package IkiWiki::PageSpec;
305 +sub check_named_spec($$;@) {
307 + my $specName=shift;
310 + error("Unable to find specFuncs in params to check_named_spec()!") unless exists $params{specFuncs};
312 + my $specFuncsRef=$params{specFuncs};
314 + return IkiWiki::FailReason->new("Named page spec '$specName' is not valid")
315 + unless (substr($specName, 0, 1) eq '~');
317 + $specName = substr($specName, 1);
319 + if (exists $specFuncsRef->{$specName}) {
320 + # remove the named spec from the spec refs
321 + # when we recurse to avoid infinite recursion
322 + my $sub = $specFuncsRef->{$specName};
323 + delete $specFuncsRef->{$specName};
324 + my $result = $sub->($page, %params);
325 + $specFuncsRef->{$specName} = $sub;
328 + return IkiWiki::FailReason->new("Page spec '$specName' does not exist");
332 +sub check_named_spec_existential($$$;@) {
334 + my $specName=shift;
338 + error("Unable to find specFuncs in params to check_named_spec_existential()!") unless exists $params{specFuncs};
339 + my $specFuncsRef=$params{specFuncs};
341 + return IkiWiki::FailReason->new("Named page spec '$specName' is not valid")
342 + unless (substr($specName, 0, 1) eq '~');
343 + $specName = substr($specName, 1);
345 + if (exists $specFuncsRef->{$specName}) {
346 + # remove the named spec from the spec refs
347 + # when we recurse to avoid infinite recursion
348 + my $sub = $specFuncsRef->{$specName};
349 + delete $specFuncsRef->{$specName};
351 + foreach my $nextpage (keys %IkiWiki::pagesources) {
352 + if ($sub->($nextpage, %params)) {
353 + my $tempResult = $funcref->($page, $nextpage, %params);
355 + $specFuncsRef->{$specName} = $sub;
356 + return $tempResult;
361 + $specFuncsRef->{$specName} = $sub;
362 + return IkiWiki::FailReason->new("No page in spec '$specName' was successfully matched");
364 + return IkiWiki::FailReason->new("Named page spec '$specName' does not exist");
368 sub match_glob ($$;@) {
373 + if (substr($glob, 0, 1) eq '~') {
374 + return check_named_spec($page, $glob, %params);
377 my $from=exists $params{location} ? $params{location} : '';
380 @@ -1782,11 +1877,12 @@ sub match_internal ($$;@) {
382 sub match_link ($$;@) {
384 - my $link=lc(shift);
385 + my $fulllink=shift;
387 + my $link=lc($fulllink);
389 my $from=exists $params{location} ? $params{location} : '';
393 if ($link =~ m!^\.! && defined $from) {
395 @@ -1804,19 +1900,32 @@ sub match_link ($$;@) {
398 return IkiWiki::SuccessReason->new("$page links to page $p matching $link")
399 - if match_glob($p, $link, %params);
400 + if match_glob($p, $fulllink, %params);
403 return IkiWiki::FailReason->new("$page does not link to $link");
406 sub match_backlink ($$;@) {
407 - return match_link($_[1], $_[0], @_);
409 + my $backlink=shift;
412 + if (substr($backlink, 0, 1) eq '~') {
413 + return check_named_spec_existential($page, $backlink, \&match_backlink, @params);
416 + return match_link($backlink, $page, @params);
419 sub match_created_before ($$;@) {
424 + if (substr($testpage, 0, 1) eq '~') {
425 + return check_named_spec_existential($page, $testpage, \&match_created_before, @params);
428 if (exists $IkiWiki::pagectime{$testpage}) {
429 if ($IkiWiki::pagectime{$page} < $IkiWiki::pagectime{$testpage}) {
430 @@ -1834,6 +1943,11 @@ sub match_created_before ($$;@) {
431 sub match_created_after ($$;@) {
436 + if (substr($testpage, 0, 1) eq '~') {
437 + return check_named_spec_existential($page, $testpage, \&match_created_after, @params);
440 if (exists $IkiWiki::pagectime{$testpage}) {
441 if ($IkiWiki::pagectime{$page} > $IkiWiki::pagectime{$testpage}) {