X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/cbd7b8a1f22d09895fe0ad4de0e4358c02f82aef..b9d2ee880ccfe54035a7c5e2d14917d84ec8fd45:/doc/todo/tracking_bugs_with_dependencies.mdwn?ds=inline
diff --git a/doc/todo/tracking_bugs_with_dependencies.mdwn b/doc/todo/tracking_bugs_with_dependencies.mdwn
index 1b99d70b5..bfdbf0875 100644
--- a/doc/todo/tracking_bugs_with_dependencies.mdwn
+++ b/doc/todo/tracking_bugs_with_dependencies.mdwn
@@ -1,3 +1,5 @@
+[[!tag patch patch/core]]
+
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
@@ -11,6 +13,8 @@ I like the idea of [[tips/integrated_issue_tracking_with_ikiwiki]], and I do so
>
>> I thought about this briefly, and got about that far.. glad you got
>> further. :-) --[[Joey]]
+
+>> Or, one [[!taglink could_also_refer|pagespec_in_DL_style]] to the language of [[!wikipedia description logics]]: their formulas actually define classes of objects through quantified relations to other classes. --Ivan Z.
>
> 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.
@@ -58,6 +62,7 @@ I like the idea of [[tips/integrated_issue_tracking_with_ikiwiki]], and I do so
>> 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]]
@@ -65,13 +70,17 @@ I like the idea of [[tips/integrated_issue_tracking_with_ikiwiki]], and I do so
>>> If you memoize the outcomes of the named pagespecs you can make in O(N.X), no?
>>> -- [[Will]]
-> One quick further thought. All the above discussion assumes that 'dependency' is the
+>>>> 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]]
+>> I saw that this issue is targeted at by the work on [[structured page data#another_kind_of_links]]. --Ivan Z.
+
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.
@@ -97,155 +106,651 @@ this todo [[todo/Add_a_plugin_to_list_available_pre-processor_commands]].
>> 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]]
-Immediately below is a patch for IkiWiki.pm. Below that is a new plugin `definepagespec `
-which behaves like `shortcut` for pagespecs.
+>>> 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]]
+
+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
+account all comments above (which doesn't mean it is above reproach :) ). --[[Will]]
+
+> Very belated code review of last version of the patch:
+>
+> * `is_globlist` is no longer needed
+
+>> Good :)
+
+> * I don't understand why the pagespec match regexp is changed
+> from having flags `igx` to `ixgs`. Don't see why you
+> want `.` to match '\n` in it, and don't see any `.` in the regexp
+> anyway?
+
+>> Because you have to define all the named pagespecs in the pagespec, you sometimes end up with very long pagespecs. I found it useful to split them over multiple lines. That didn't work at one point and I added the 's' to make it work. I may have further altered the regex since then to make the 's' redundant. Remove it and see if multi-line pagespecs still work. :)
+
+>>> Well, I can tell you that multi-line pagespecs are supported w/o
+>>> your patch .. I use them all the time. The reason I find your
+>>> use of `/s` unlikely is because without it `\s` already matches
+>>> a newline. Only if you want to treat a newline as non-whitespace
+>>> is `/s` typically necessary. --[[Joey]]
+
+> * Some changes of `@_` to `%params` in `pagespec_makeperl` do not
+> make sense to me. I don't see where \%params is defined and populated,
+> except with `\$params{specFunc}`.
+
+>> I'm not a perl hacker. This was a mighty battle for me to get going.
+>> There is probably some battlefield carnage from my early struggles
+>> learning perl left here. Part of this is that @_ / @params already
+>> existed as a way of passing in extra parameters. I didn't want to
+>> pollute that top level namespace - just at my own parameter (a hash)
+>> which contained the data I needed.
+
+>>> I think I understand how the various `%params`
+>>> (there's not just one) work in your code now, but it's really a mess.
+>>> Explaining it in words would take pages.. It could be fixed by,
+>>> in `pagespec_makeperl` something like:
+>>>
+>>> my %specFuncs;
+>>> push @_, specFuncs => \%specFuncs;
+>>>
+>>> With that you have the hash locally available for populating
+>>> inside `pagespec_makeperl`, and when the `match_*` functions
+>>> are called the same hash data will be available inside their
+>>> `@_` or `%params`. No need to change how the functions are called
+>>> or do any of the other hacks.
+>>>
+>>> Currently, specFuncs is populated by building up code
+>>> that recursively calls `pagespec_makeperl`, and is then
+>>> evaluated when the pagespec gets evaluated. My suggested
+>>> change to `%params` will break that, but that had to change
+>>> anyway.
+>>>
+>>> It probably has a security hole, and is certianly inviting
+>>> one, since the pagespec definition is matched by a loose regexp (`.*`)
+>>> and then subject to string interpolation before being evaluated
+>>> inside perl code. I recently changed ikiwiki to never interpolate
+>>> user-supplied strings when translating pagespecs, and that
+>>> needs to happen here too. The obvious way, it seems to me,
+>>> is to not generate perl code, but just directly run perl code that
+>>> populates specFuncs.
+
+>>>> I don't think this is as bad as you make out, but your addition of the
+>>>> data array will break with the recursion my patch adds in pagespec_makeperl.
+>>>> To fix that I'll need to pass a reference to that array into pagespec_makeperl.
+>>>> I think I can then do the same thing to $params{specFuncs}. -- [[Will]]
+
+>>>>> You're right -- I did not think the recursive case through.
+>>>>> --[[Joey]]
+
+> * Seems that the only reason `match_glob` has to check for `~` is
+> because when a named spec appears in a pagespec, it is translated
+> to `match_glob("~foo")`. If, instead, `pagespec_makeperl` checked
+> for named specs, it could convert them into `check_named_spec("foo")`
+> and avoid that ugliness.
+
+>> Yeah - I wanted to make named specs syntactically different on my first pass. You are right in that this could be made a fallback - named specs always override pagenames.
+
+> * The changes to `match_link` seem either unecessary, or incomplete.
+> Shouldn't it check for named specs and call
+> `check_named_spec_existential`?
+
+>> An earlier version did. Then I realised it wasn't actually needed in that case - match_link() already included a loop that was like a type of existential matching. Each time through the loop it would
+>> call match_glob(). match_glob() in turn will handle the named spec. I tested this version briefly and it seemed to work. I remember looking at this again later and wondering if I had mis-understood
+>> some of the logic in match_link(), which might mean there are cases where you would need an explicit call to check_named_spec_existential() - I never checked it properly after having that thought.
+
+>>> In the common case, `match_link` does not call `match_glob`,
+>>> because the link target it is being asked to check for is a single
+>>> page name, not a glob.
+
+>>>> A named pagespec should fall into the glob case. These two pagespecs should be the same:
+
+ link(a*)
+
+>>>> and
+
+ define(aStar, a*) and link(~aStar)
+
+>>>> In the first case, we want the pagespec to match any page that links to a page matching the glob.
+>>>> In the second case, we want the pagespec to match any page that links to a page matching the named spec.
+>>>> match_link() was already doing existential part. The patches to this code were simply to remove the `lc()`
+>>>> call from the named pagespec name. Can that `lc` be removed entirely? -- [[Will]]
+
+>>>>> I think we could get rid of it. `bestlink` will lc it itself
+>>>>> if the uppercase version does not exist; `match_glob` matches
+>>>>> insensitively.
+>>>>> --[[Joey]]
+
+> * Generally, the need to modify `match_*` functions so that they
+> check for and handle named pagespecs seems suboptimal, if
+> only because there might be others people may want to use named
+> pagespecs with. It would be possible to move this check
+> to `pagespec_makeperl`, by having it check if the parameter
+> passed to a pagespec function looked like a named pagespec.
+> The only issue is that some pagespec functions take a parameter
+> that is not a page name at all, and it could be weird
+> if such a parameter were accidentially interpreted as a named
+> pagespec. (But, that seems unlikely to happen.)
+
+>> Possibly. I'm not sure which I prefer between the current solution and that one. Each have advantages and disadvantages.
+>> It really isn't much code for the match functions to add a call to check_named_spec_existential().
+
+>>> But if a plugin adds its own match function, it has
+>>> to explicitly call that code to support named pagespecs.
+
+>>>> Yes, and it can do that in just three lines of code. But if we automatically check for named pagespecs all the time we
+>>>> potentially break any matching function that doesn't accept pages, or wants to use multiple arguments.
+
+>>>>> 3 lines of code, plus the functions called become part of the API,
+>>>>> don't forget about that..
+>>>>>
+>>>>> Yes, I think that is the tradeoff, the question is whether to export
+>>>>> the additional complexity needed for that flexability.
+>>>>>
+>>>>> I'd be suprised if multiple argument pagespecs become necessary..
+>>>>> with the exception of this patch there has been no need for them yet.
+>>>>>
+>>>>> There are lots of pagespecs that take data other than pages,
+>>>>> indeed, that's really the common case. So far, none of them
+>>>>> seem likely to take data that starts with a `~`. Perhaps
+>>>>> the thing to do would be to check if `~foo` is a known,
+>>>>> named pagespec, and if not, just pass it through unchanged.
+>>>>> Then there's little room for ambiguity, and this also allows
+>>>>> pagespecs like `glob(~foo*)` to match the literal page `~foo`.
+>>>>> (It will make pagespec_merge even harder tho.. see below.)
+>>>>> --[[Joey]]
+
+>>>>>> I've already used multi-argument pagespec match functions in
+>>>>>> my data plugin. It is used for having different types of links. If
+>>>>>> you want to have multiple types of links, then the match function
+>>>>>> for them needs to take both the link name and the link type.
+>>>>>> I'm trying to think of a way we could have both - automatically
+>>>>>> handle the existential case unless the function indicates somehow
+>>>>>> that it'll do it itself. Any ideas? -- [[Will]]
+
+> * I need to check if your trick to avoid infinite recursion
+> works if there are two named specs that recursively
+> call one-another. I suspect it does, but will test this
+> myself..
+
+>> It worked for me. :)
+
+> * I also need to verify if memoizing the named pagespecs has
+> really guarded against very expensive pagespecs DOSing the wiki..
+
+> --[[Joey]]
+
+>> There is one issue that I've been thinking about that I haven't raised anywhere (or checked myself), and that is how this all interacts with page dependencies.
+>> Firstly, I'm not sure anymore that the `pagespec_merge` function will continue to work in all cases.
+
+>>> The problem I can see there is that if two pagespecs
+>>> get merged and both use `~foo` but define it differently,
+>>> then the second definition might be used at a point when
+>>> it shouldn't (but I haven't verified that really happens).
+>>> That could certianly be a show-stopper. --[[Joey]]
+
+>>>> I think this can happen in the new closure based code. I don't think this could happen in the old code. -- [[Will]]
+
+>>>> Even if that works, this is a good argument for having a syntactic difference between named pagespecs and normal pages.
+>>>> If you're joining two pagespecs with 'or', you don't want a named pagespec in the first part overriding a page name in the
+>>>> second part. Oh, and I assume 'or' has the right operator precedence that "a and b or c" is "(a and b) or c", and not "a and (b or c)" -- [[Will]]
+
+>>>>> Looks like its bracketed in the code anyway... -- [[Will]]
+
+>>>> Perhaps the thing to do is to have a `clear_defines()`
+>>>> function, then merging `A` and `B` yields `(A) or (clear_defines() and (B))`
+>>>> That would deal with both the cases where `A` and `B` differently
+>>>> define `~foo` as well as with the case where `A` defines `~foo` while
+>>>> `B` uses it to refer to a literal page.
+>>>> --[[Joey]]
+
+>>>>> I don't think this will work with the new patch, and I don't think it was needed with the old one.
+>>>>> Under the old patch, pagespec_makeperl() generated a string of unevaluated, self-contained, perl
+>>>>> code. When a new named pagespec was defined, a recursive call was made to get the perl code
+>>>>> for the pagespec, and then that code was used to add something like `$params{specFuncs}->{name} = sub {recursive code} and `
+>>>>> to the result of the calling function. This means that at pagespec testing time, when this code is executed, the
+>>>>> specFuncs hash is built up as the pagespec is checked. In the case of the 'or' used above, later redefinitions of
+>>>>> a named pagespec would have redefined the specFunc at the right time. It should have just worked. However...
+
+>>>>> Since my original patch, you started using closures for security reasons (and I can see the case for that). Unfortunately this
+>>>>> means that the generated perl code is no longer self-contained - it needs to be evaluated in the same closure it was generated
+>>>>> so that it has access to the data array. To make this work with the recursive call I had two options: a) make the data array a
+>>>>> reference that I pass around through the pagespec_makeperl() functions and have available when the code is finally evaluated
+>>>>> in pagespec_translate(), or b) make sure that each pagespec is evaluated in its correct closure and a perl function is returned, not a
+>>>>> string containing unevaluated perl code.
+
+>>>>> I went with option b). I did it in such a way that the hash of specfuncs is built up at translation time, not at execution time. This
+>>>>> means that with the new code you can call specfuncs that get defined out of order:
+
+ ~test and define(~test, blah)
+
+>>>>> but it also means that using a simple 'or' to join two pagespecs wont work. If you do something like this:
+
+ ~test and define(~test, foo) and define(~test, baz)
+
+>>>>> then the last definition (baz) takes precedence.
+>>>>> In the process of writing this I think I've come up with a way to change this back the way it was, still using closures. -- [[Will]]
+
+>>> My [[remove-pagespec-merge|should_optimise_pagespecs]] branch has now
+>>> solved all this by deleting the offending function :-) --[[smcv]]
+
+>> Secondly, it seems that there are two types of dependency, and ikiwiki
+>> currently only handles one of them. The first type is "Rebuild this
+>> page when any of these other pages changes" - ikiwiki handles this.
+>> The second type is "rebuild this page when set of pages referred to by
+>> this pagespec changes" - ikiwiki doesn't seem to handle this. I
+>> suspect that named pagespecs would make that second type of dependency
+>> more important. I'll try to come up with a good example. -- [[Will]]
+
+>>> Hrm, I was going to build an example of this with backlinks, but it
+>>> looks like that is handled as a special case at the moment (line 458 of
+>>> render.pm). I'll see if I can breapk
+>>> things another way. Fixing this properly would allow removal of that special case. -- [[Will]]
+
+>>>> I can't quite understand the distinction you're trying to draw
+>>>> between the two types of dependencies. Backlinks are a very special
+>>>> case though and I'll be suprised if they fit well into pagespecs.
+>>>> --[[Joey]]
+
+>>>>> The issue is that the existential pagespec matching allows you to build things that have similar
+>>>>> problems to backlinks.
+>>>>> e.g. the following inline:
+
+ \[[!inline pages="define(~done, link(done)) and link(~done)" archive=yes]]
+
+>>>>> includes any page that links to a page that links to done. Now imagine I add a new link to 'done' on
+>>>>> some random page somewhere - a page which some other page links to which didn't previously get included - the set of pages accepted by the pagespec, and hence the set of
+>>>>> pages inlined, will change. But, there is no dependency anywhere on the page that I altered, so
+>>>>> ikiwiki will not rebuild the page with the inline in it. What is happening is that the page that I altered affects
+>>>>> the set of pages matched by the pagespec without itself being matched by the pagespec, and hence included in the dependency list.
+
+>>>>> To make this work well, I think you need to recognise two types of dependencies for each page (and no
+>>>>> special cases for particular types of links, eg backlinks). The first type of dependency says, "The content of
+>>>>> this page depends upon the content of these other pages". The `add_depends()` in the shortcuts
+>>>>> plugin is of this form: any time the shortcuts page is edited, any page with a shortcut on it
+>>>>> is rebuilt. The inline plugin also needs to add dependencies of this form to detect when the inlined
+>>>>> content changes. By contrast, the map plugin does not need a dependency of this form, because it
+>>>>> doesn't actually care about the content of any pages, just which pages it needs to include (which we'll handle next).
+
+>>>>> The second type of dependency says, "The content of this page depends upon the exact set of pages matched
+>>>>> by this pagespec". The first type of dependency was about the content of some pages, the second type is about
+>>>>> which pages get matched by a pagespec. This is the type of dependency tracking that the map plugin needs.
+>>>>> If the set of pages matched by map pagespec changes, then the page with the map on it needs to be rebuilt to show a different list of pages.
+>>>>> Inline needs this type of dependency as well as the previous type - This type handles a change in which pages
+>>>>> are inlined, the previous type handles a change in the content of any of those pages. Shortcut does not need this type of
+>>>>> dependency. Most of the places that use `add_depends()` seem to need this type of dependency rather than the first type.
+
+>>>>>> Note that inline and map currently achieve the second type of dependency by
+>>>>>> explicitly calling `add_depends` for each page the displayed.
+>>>>>> If any of those pages are removed, the regular pagespec would not
+>>>>>> match them -- since they're gone. However, the explicit dependency
+>>>>>> on them does cause them to match. It's an ugly corner I'd like to
+>>>>>> get rid of. --[[Joey]]
+
+>>>>> Implementation Details: The first type of dependency can be handled very similarly to the current
+>>>>> dependency system. You just need to keep a list of pages that the content depends upon. You could
+>>>>> keep that list as a pagespec, but if you do this you might want to check that the pagespec doesn't change,
+>>>>> possibly by adding a dependency of the second type along with the dependency of the first type.
+
+>>>>>> An example of the current system not tracking enough data is
+>>>>>> where A inlines B which inlines C. A change to C will cause B to
+>>>>>> rebuild, but A will not "notice" that B has implicitly changed.
+>>>>>> That example suggests it might be fixable without explicitly storing
+>>>>>> data, by causing a rebuild of B to be treated as a change to B.
+>>>>>> --[[Joey]]
+
+>>>>> The second type of dependency is a little more tricky. For each page, we'd need a list of pagespecs that
+>>>>> the page depended on, and for each pagespec you'd want to store the list of pages that currently match it.
+>>>>> On refresh, you'd need to check each pagespec to see if the set of pages that match it has changed, and if
+>>>>> that set has changed, then rebuild the dependent page(s). Oh, and for this second type of dependency, I
+>>>>> don't think you can merge pagespecs. If I wanted to know if either "\*" or "link(done)" changes, then just checking
+>>>>> to see if the set of pages matched by "\* or link(done)" changes doesn't work.
+
+>>>>> The current system works because even though you usually want dependencies of the second type, the set of pages
+>>>>> referred to by a pagespec can only change if one of those pages itself changes. i.e. A dependency check of the
+>>>>> first type will catch a dependency change of the second type with current pagespecs.
+>>>>> This doesn't work with backlinks, and it doesn't work with existential matching. Backlinks are currently special-cased. I don't know
+>>>>> how to special-case existential matching - I suspect you're better off just getting the dependency tracking right.
+
+>>>>> I also tried to come up with other possible solutions: e.g. can we find the dependencies for a pagespec? That
+>>>>> would be the set of pages where a change on one of those pages could lead to a change in the set of pages matched by the pagespec.
+>>>>> For old-style pagespecs without backlinks, the dependency set for a pagespec is the same as the set of pages the pagespec matches.
+>>>>> Unfortunately, with existential matching, the set of pages that each
+>>>>> pagespec depends upon can quickly become "*", which is not very useful. -- [[Will]]
+
+Patch updated to use closures rather than inline generated code for named pagespecs. Also includes some new use of ErrorReason where appropriate. -- [[Will]]
+
+> * Perl really doesn't need forward declarations, honest!
+
+>> It complained (warning, not error) when I didn't use the forward declaration. :(
+
+> * I have doubts about memoizing the anonymous sub created by
+> `pagespec_translate`.
+
+>> This is there explicitly to make sure that runtime is polynomial and not exponential.
+
+> * Think where you wrote `+{}` you can just write `{}`
-diff --git a/IkiWiki.pm b/IkiWiki.pm
-index e476521..1d2d48c 100644
---- a/IkiWiki.pm
-+++ b/IkiWiki.pm
-@@ -14,7 +14,7 @@ use open qw{:utf8 :std};
- use vars qw{%config %links %oldlinks %pagemtime %pagectime %pagecase
- %pagestate %renderedfiles %oldrenderedfiles %pagesources
- %destsources %depends %hooks %forcerebuild $gettext_obj
-- %loaded_plugins};
-+ %loaded_plugins %named_pagespec};
-
- use Exporter q{import};
- our @EXPORT = qw(hook debug error template htmlpage add_depends pagespec_match
-@@ -22,7 +22,7 @@ our @EXPORT = qw(hook debug error template htmlpage add_depends pagespec_match
- displaytime will_render gettext urlto targetpage
- add_underlay
- %config %links %pagestate %renderedfiles
-- %pagesources %destsources);
-+ %pagesources %destsources %named_pagespec);
- our $VERSION = 2.00; # plugin interface version, next is ikiwiki version
- our $version='unknown'; # VERSION_AUTOREPLACE done by Makefile, DNE
- my $installdir=''; # INSTALLDIR_AUTOREPLACE done by Makefile, DNE
-@@ -1271,7 +1271,7 @@ sub loadindex () { #{{{
- %oldrenderedfiles=%pagectime=();
- if (! $config{rebuild}) {
- %pagesources=%pagemtime=%oldlinks=%links=%depends=
-- %destsources=%renderedfiles=%pagecase=%pagestate=();
-+ %destsources=%renderedfiles=%pagecase=%pagestate=%named_pagespec=();
- }
- my $in;
- if (! open ($in, "<", "$config{wikistatedir}/indexdb")) {
-@@ -1729,6 +1729,8 @@ sub match_glob ($$;@) { #{{{
-
- my $from=exists $params{location} ? $params{location} : '';
-
-+ print "Matching glob $glob \n";
-+
- # relative matching
- if ($glob =~ m!^\./!) {
- $from=~s#/?[^/]+$##;
-@@ -1736,6 +1738,18 @@ sub match_glob ($$;@) { #{{{
- $glob="$from/$glob" if length $from;
- }
-
-+ if (substr($glob, 0, 1) eq '~') {
-+ my $specname = substr($glob, 1);
-+ print "Checking for pagespec named $specname \n";
-+ if (exists $IkiWiki::named_pagespec{$specname}) {
-+ my $spec = $IkiWiki::named_pagespec{$specname};
-+ return IkiWiki::pagespec_match($page, $spec, %params);
-+ } else {
-+ print "Couldn't find pagespec\n";
-+ return IkiWiki::FailReason->new("Page spec $specname referenced on page $page does not exist");
-+ }
-+ }
-+
- my $regexp=IkiWiki::glob2re($glob);
- if ($page=~/^$regexp$/i) {
- if (! IkiWiki::isinternal($page) || $params{internal}) {
-@@ -1756,11 +1770,36 @@ sub match_internal ($$;@) { #{{{
-
- sub match_link ($$;@) { #{{{
- my $page=shift;
-- my $link=lc(shift);
-+ my $fulllink=shift;
-+ my $link=lc($fulllink);
- my %params=@_;
-
-+ print "Matching link $fulllink \n";
-+
- my $from=exists $params{location} ? $params{location} : '';
-
-+ if (substr($fulllink, 0, 1) eq '~') {
-+ my $specname = substr($fulllink, 1);
-+ print "Checking link pagespec $specname \n";
-+ if (exists $IkiWiki::named_pagespec{$specname}) {
-+ my $spec = $IkiWiki::named_pagespec{$specname};
-+
-+ print "Checking all pages against $spec\n";
-+
-+ foreach my $nextpage (keys %IkiWiki::pagesources) {
-+ print "Checking $nextpage against $spec\n";
-+ if (pagespec_match($nextpage, $spec, %params) && IkiWiki::PageSpec::match_link($page, $nextpage, %params)) {
-+ return IkiWiki::SuccessReason->new("$page links to page $nextpage matching $link")
-+ }
-+ }
-+
-+ return IkiWiki::FailReason->new("$page has no links to any pages that match $spec");
-+ } else {
-+ print "Pagespec $specname not found\n";
-+ return IkiWiki::FailReason->new("$page cannot link to nonexistent spec name $specname");
-+ }
-+ }
-+
- # relative matching
- if ($link =~ m!^\.! && defined $from) {
- $from=~s#/?[^/]+$##;
+>> Possibly :) -- [[Will]]
----
-#!/usr/bin/perl
-package IkiWiki::Plugin::definepagespec;
-
-use warnings;
-use strict;
-use IkiWiki 2.00;
-
-sub import { #{{{
- hook(type => "getsetup", id => "definepagespec", call => \&getsetup);
- hook(type => "refresh", id => "definepagespec", call => \&refresh);
- hook(type => "preprocess", id => "definepagespec", call => \&preprocess);
-} #}}}
-
-sub getsetup () { #{{{
- return
- plugin => {
- safe => 1,
- rebuild => undef,
- },
-} #}}}
-
-sub refresh () { #{{{
- # Preprocess the shortcuts page to get all the available shortcuts
- # defined before other pages are rendered.
- my $srcfile=srcfile("pagespecs.mdwn", 1);
- if (! defined $srcfile) {
- error(gettext("definepagespec plugin will not work without a pagespecs.mdwn"));
- }
- IkiWiki::preprocess("pagespecs", "pagespecs", readfile($srcfile));
-} # }}}
-
-sub preprocess (@) { #{{{
- my %params=@_;
-
- if (! defined $params{name} || ! defined $params{spec}) {
- error gettext("missing name or spec parameter");
- }
-
- $IkiWiki::named_pagespec{$params{name}} = $params{spec};
-
- #translators: This is used to display what shortcuts are defined.
- #translators: First parameter is the name of the shortcut, the second
- #translators: is an URL.
- return sprintf(gettext("pagespec %s refers to %s"), $params{name}, $params{spec});
-} # }}}
-
-1
+ diff --git a/IkiWiki.pm b/IkiWiki.pm
+ index 061a1c6..1e78a63 100644
+ --- a/IkiWiki.pm
+ +++ b/IkiWiki.pm
+ @@ -1774,8 +1774,12 @@ sub pagespec_merge ($$) {
+ return "($a) or ($b)";
+ }
+
+ -sub pagespec_translate ($) {
+ +# is perl really so dumb it requires a forward declaration for recursive calls?
+ +sub pagespec_translate ($$);
+ +
+ +sub pagespec_translate ($$) {
+ my $spec=shift;
+ + my $specFuncsRef=shift;
+
+ # Convert spec to perl code.
+ my $code="";
+ @@ -1789,7 +1793,9 @@ sub pagespec_translate ($) {
+ |
+ \) # )
+ |
+ - \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
+ )
+ @@ -1805,10 +1811,19 @@ sub pagespec_translate ($) {
+ elsif ($word eq "(" || $word eq ")" || $word eq "!") {
+ $code.=' '.$word;
+ }
+ - elsif ($word =~ /^(\w+)\((.*)\)$/) {
+ + elsif ($word =~ /^define\(\s*(~\w+)\s*,(.*)\)$/s) {
+ + my $name = $1;
+ + my $subSpec = $2;
+ + my $newSpecFunc = pagespec_translate($subSpec, $specFuncsRef);
+ + return if $@ || ! defined $newSpecFunc;
+ + $specFuncsRef->{$name} = $newSpecFunc;
+ + push @data, qq{Created named pagespec "$name"};
+ + $code.="IkiWiki::SuccessReason->new(\$data[$#data])";
+ + }
+ + elsif ($word =~ /^(\w+)\((.*)\)$/s) {
+ if (exists $IkiWiki::PageSpec::{"match_$1"}) {
+ push @data, $2;
+ - $code.="IkiWiki::PageSpec::match_$1(\$page, \$data[$#data], \@_)";
+ + $code.="IkiWiki::PageSpec::match_$1(\$page, \$data[$#data], \@_, specFuncs => \$specFuncsRef)";
+ }
+ else {
+ push @data, qq{unknown function in pagespec "$word"};
+ @@ -1817,7 +1832,7 @@ sub pagespec_translate ($) {
+ }
+ else {
+ push @data, $word;
+ - $code.=" IkiWiki::PageSpec::match_glob(\$page, \$data[$#data], \@_)";
+ + $code.=" IkiWiki::PageSpec::match_glob(\$page, \$data[$#data], \@_, specFuncs => \$specFuncsRef)";
+ }
+ }
+
+ @@ -1826,7 +1841,7 @@ sub pagespec_translate ($) {
+ }
+
+ no warnings;
+ - return eval 'sub { my $page=shift; '.$code.' }';
+ + return eval 'memoize (sub { my $page=shift; '.$code.' })';
+ }
+
+ sub pagespec_match ($$;@) {
+ @@ -1839,7 +1854,7 @@ sub pagespec_match ($$;@) {
+ unshift @params, 'location';
+ }
+
+ - my $sub=pagespec_translate($spec);
+ + my $sub=pagespec_translate($spec, +{});
+ return IkiWiki::ErrorReason->new("syntax error in pagespec \"$spec\"")
+ if $@ || ! defined $sub;
+ return $sub->($page, @params);
+ @@ -1850,7 +1865,7 @@ sub pagespec_match_list ($$;@) {
+ my $spec=shift;
+ my @params=@_;
+
+ - my $sub=pagespec_translate($spec);
+ + my $sub=pagespec_translate($spec, +{});
+ error "syntax error in pagespec \"$spec\""
+ if $@ || ! defined $sub;
+
+ @@ -1872,7 +1887,7 @@ sub pagespec_match_list ($$;@) {
+ sub pagespec_valid ($) {
+ my $spec=shift;
+
+ - my $sub=pagespec_translate($spec);
+ + my $sub=pagespec_translate($spec, +{});
+ return ! $@;
+ }
+
+ @@ -1919,6 +1934,68 @@ sub new {
+
+ package IkiWiki::PageSpec;
+
+ +sub check_named_spec($$;@) {
+ + my $page=shift;
+ + my $specName=shift;
+ + my %params=@_;
+ +
+ + return IkiWiki::ErrorReason->new("Unable to find specFuncs in params to check_named_spec()!")
+ + unless exists $params{specFuncs};
+ +
+ + my $specFuncsRef=$params{specFuncs};
+ +
+ + return IkiWiki::ErrorReason->new("Named page spec '$specName' is not valid")
+ + unless (substr($specName, 0, 1) eq '~');
+ +
+ + if (exists $specFuncsRef->{$specName}) {
+ + # remove the named spec from the spec refs
+ + # when we recurse to avoid infinite recursion
+ + my $sub = $specFuncsRef->{$specName};
+ + delete $specFuncsRef->{$specName};
+ + my $result = $sub->($page, %params);
+ + $specFuncsRef->{$specName} = $sub;
+ + return $result;
+ + } else {
+ + return IkiWiki::ErrorReason->new("Page spec '$specName' does not exist");
+ + }
+ +}
+ +
+ +sub check_named_spec_existential($$$;@) {
+ + my $page=shift;
+ + my $specName=shift;
+ + my $funcref=shift;
+ + my %params=@_;
+ +
+ + return IkiWiki::ErrorReason->new("Unable to find specFuncs in params to check_named_spec_existential()!")
+ + unless exists $params{specFuncs};
+ + my $specFuncsRef=$params{specFuncs};
+ +
+ + return IkiWiki::ErrorReason->new("Named page spec '$specName' is not valid")
+ + unless (substr($specName, 0, 1) eq '~');
+ +
+ + if (exists $specFuncsRef->{$specName}) {
+ + # remove the named spec from the spec refs
+ + # when we recurse to avoid infinite recursion
+ + my $sub = $specFuncsRef->{$specName};
+ + delete $specFuncsRef->{$specName};
+ +
+ + foreach my $nextpage (keys %IkiWiki::pagesources) {
+ + if ($sub->($nextpage, %params)) {
+ + my $tempResult = $funcref->($page, $nextpage, %params);
+ + if ($tempResult) {
+ + $specFuncsRef->{$specName} = $sub;
+ + return IkiWiki::SuccessReason->new("Existential check of '$specName' matches because $tempResult");
+ + }
+ + }
+ + }
+ +
+ + $specFuncsRef->{$specName} = $sub;
+ + return IkiWiki::FailReason->new("No page in spec '$specName' was successfully matched");
+ + } else {
+ + return IkiWiki::ErrorReason->new("Named page spec '$specName' does not exist");
+ + }
+ +}
+ +
+ sub derel ($$) {
+ my $path=shift;
+ my $from=shift;
+ @@ -1937,6 +2014,10 @@ sub match_glob ($$;@) {
+ my $glob=shift;
+ my %params=@_;
+
+ + if (substr($glob, 0, 1) eq '~') {
+ + return check_named_spec($page, $glob, %params);
+ + }
+ +
+ $glob=derel($glob, $params{location});
+
+ my $regexp=IkiWiki::glob2re($glob);
+ @@ -1959,8 +2040,9 @@ sub match_internal ($$;@) {
+
+ sub match_link ($$;@) {
+ my $page=shift;
+ - my $link=lc(shift);
+ + my $fullLink=shift;
+ my %params=@_;
+ + my $link=lc($fullLink);
+
+ $link=derel($link, $params{location});
+ my $from=exists $params{location} ? $params{location} : '';
+ @@ -1975,25 +2057,37 @@ sub match_link ($$;@) {
+ }
+ else {
+ return IkiWiki::SuccessReason->new("$page links to page $p matching $link")
+ - if match_glob($p, $link, %params);
+ + if match_glob($p, $fullLink, %params);
+ $p=~s/^\///;
+ $link=~s/^\///;
+ return IkiWiki::SuccessReason->new("$page links to page $p matching $link")
+ - if match_glob($p, $link, %params);
+ + if match_glob($p, $fullLink, %params);
+ }
+ }
+ return IkiWiki::FailReason->new("$page does not link to $link");
+ }
+
+ sub match_backlink ($$;@) {
+ - 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 ($$;@) {
+ my $page=shift;
+ my $testpage=shift;
+ my %params=@_;
+ -
+ +
+ + if (substr($testpage, 0, 1) eq '~') {
+ + return check_named_spec_existential($page, $testpage, \&match_created_before, %params);
+ + }
+ +
+ $testpage=derel($testpage, $params{location});
+
+ if (exists $IkiWiki::pagectime{$testpage}) {
+ @@ -2014,6 +2108,10 @@ sub match_created_after ($$;@) {
+ my $testpage=shift;
+ my %params=@_;
+
+ + if (substr($testpage, 0, 1) eq '~') {
+ + return check_named_spec_existential($page, $testpage, \&match_created_after, %params);
+ + }
+ +
+ $testpage=derel($testpage, $params{location});
+
+ if (exists $IkiWiki::pagectime{$testpage}) {