757 lines
38 KiB
Markdown
757 lines
38 KiB
Markdown
[[!tag patch patch/core]]
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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]]
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> I started having a think about this. I'm going to start with the idea that expanding
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> the pagespec syntax is the way to attack this. It seems that any pagespec that is going
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> to represent "all bugs with no dependencies on bugs not marked as done" is going to
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> need some way to represent "bugs not marked as done" as a collection of pages, and
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> then represent "bugs which do not link to pages in the previous collection".
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>
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> One way to do this would be to introduce variables into the pagespec, along with
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> universal and/or existential [[!wikipedia Quantification]]. That looks quite complex.
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>
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>> I thought about this briefly, and got about that far.. glad you got
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>> further. :-) --[[Joey]]
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>> 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.
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>
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> Another option would be go with a more functional syntax. The concept here would
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> be to allow a pagespec to appear in a 'pagespec function' anywhere a page can. e.g.
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> I could pass a pagespec to `link()` and that would return true if there is a link to any
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> page matching the pagespec. This makes the variables and existential quantification
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> implicit. It would allow the example requested above:
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>
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>> `bugs/* and !*/Discussion and !link(bugs/* and !*/Discussion and !link(done))`
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>
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> Unfortunately, this is also going to make the pagespec parsing more complex because
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> we now need to parse nested sets of parentheses to know when the nested pagespec
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> ends, and that isn't a regular language (we can't use regular expression matching for
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> easy parsing).
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>
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>> Also, it may cause ambiguities with page names that contain parens
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>> (though some such ambigutities already exist with the pagespec syntax).
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>
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> One simplification of that would be to introduce some pagespec [[shortcuts]]. We could
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> then allow pagespec functions to take either pages, or named pagespec shortcuts. The
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> pagespec shortcuts would just be listed on a special page, like current [[shortcuts]].
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> (It would probably be a good idea to require that shortcuts on that page can only refer
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> to named pagespecs higher up that page than themselves. That would stop some
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> looping issues...) These shortcuts would be used as follows: when trying to match
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> a page (without globs) you look to see if the page exists. If it does then you have a
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> match. If it doesn't, then you look to see if a similarly named pagespec shortcut
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> exists. If it does, then you check that pagespec recursively to see if you have a match.
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> The ordering requirement on named pagespecs stops infinite recursion.
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>
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> Does that seem like a reasonable first approach?
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>
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> -- [[Will]]
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>> Having a separate page for the shortcuts feels unwieldly.. perhaps
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>> instead the shortcut could be defined earlier in the scope of the same
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>> pagespec that uses it?
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>>
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>> Example: `define(~bugs, bugs/* and !*/Discussion) and define(~openbugs, ~bugs and !link(done)) and ~openbugs and !link(~openbugs)`
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>>> That could work. parens are only ever nested 1 deep in that grammar so it is regular and the current parsing would be ok.
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>> Note that I made the "~" explicit, not implicit, so it could be left out. In the case of ambiguity between
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>> a definition and a page name, the definition would win.
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>>> 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.
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>> So, equivilant example: `define(bugs, bugs/* and !*/Discussion) and define(openbugs, bugs and !link(done)) and openbugs and !link(openbugs)`
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>>
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>> Re recursion, it is avoided.. but building a pagespec that is O(N^X) where N is the
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>> number of pages in the wiki is not avoided. Probably need to add DOS prevention.
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>> --[[Joey]]
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>>> If you memoize the outcomes of the named pagespecs you can make in O(N.X), no?
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>>> -- [[Will]]
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>>>> Yeah, guess that'd work. :-)
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> <a id="another_kind_of_links" />One quick further thought. All the above discussion assumes that 'dependency' is the
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> same as 'links to', which is not really true. For example, you'd like to be able to say
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> "This bug does not depend upon [ [ link to other bug ] ]" and not have a dependency.
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> Without having different types of links, I don't see how this would be possible.
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>
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> -- [[Will]]
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>> I saw that this issue is targeted at by the work on [[structured page data#another_kind_of_links]]. --Ivan Z.
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Okie - I've had a quick attempt at this. Initial patch attached. This one doesn't quite work.
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And there is still a lot of debugging stuff in there.
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At the moment I've added a new preprocessor plugin, `definepagespec`, which is like
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shortcut for pagespecs. To reference a named pagespec, use `~` like this:
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[ [!definepagespec name="bugs" spec="bugs/* and !*/Discussion"]]
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[ [!definepagespec name="openbugs" spec="~bugs and !link(done)"]]
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[ [!definepagespec name="readybugs" spec="~openbugs and !link(~openbugs)"]]
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At the moment the problem is in `match_link()` when we're trying to find a sub-page that
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matches the appropriate page spec. There is no good list of pages available to iterate over.
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foreach my $nextpage (keys %IkiWiki::pagesources)
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does not give me a good list of pages. I found the same thing when I was working on
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this todo [[todo/Add_a_plugin_to_list_available_pre-processor_commands]].
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> I'm not sure why iterating over `%pagesources` wouldn't work here, it's the same method
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> used by anything that needs to match a pagespec against all pages..? --[[Joey]]
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>> My uchecked hypothesis is that %pagesources is created after the refresh hook.
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>> I've also been concerned about how globally defined pagespec shortcuts would interact with
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>> the page dependancy system. Your idea of internally defined shortcuts should fix that. -- [[Will]]
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>>> You're correct, the refresh hook is run very early, before pagesources
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>>> is populated. (It will be partially populated on a refresh, but will
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>>> not be updated to reflect new pages.) Agree that internally defined
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>>> seems the way to go. --[[Joey]]
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Immediately below is a patch which seems to basically work. Lots of debugging code is still there
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and it needs a cleanup, but I thought it worth posting at this point. (I was having problems
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with old style glob lists, so i just switched them off for the moment.)
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The following three inlines work for me with this patch:
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Bugs:
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[ [!inline pages="define(~bugs, bugs/* and ! */Discussion) and ~bugs" archive="yes"]]
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OpenBugs:
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[ [!inline pages="define(~bugs, bugs/* and ! */Discussion) and define(~openbugs,~bugs and !link(done)) and ~openbugs" archive="yes"]]
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ReadyBugs:
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[ [!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"]]
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> Nice! Could the specfuncsref be passed in %params? I'd like to avoid
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> needing to change the prototype of every pagespec function, since several
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> plugins define them too. --[[Joey]]
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>> Maybe - it needs more thought. I also considered it when I was going though changing all those plugins :).
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>> My concern was that `%params` can contain other user-defined parameters,
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>> e.g. `link(target, otherparameter)`, and that means that the specFuncs could be clobbered by a user (or other
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>> weird security hole). I thought it better to separate it, but I didn't think about it too hard. I might move it to
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>> the first parameter rather than the second. Ikiwiki is my first real perl hacking and I'm still discovering
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>> good ways to write things in perl.
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>>
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>>>> `%params` contains the parameters passed to `pagespec_match`, not
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>>>> user-supplied parameters. The user-supplied parameter to a function
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>>>> like `match_glob()` or `match_link()` is passed in the second positional parameter. --[[Joey]]
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>>>>> OK. That seems reasonable then. The only problem is that my PERLfu is not strong enough to make it
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>>>>> work. I really have to wonder what substance was influencing the designers of PERL...
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>>>>> I can't figure out how to use the %params. And I'm pissed off enough with PERL that I'm not going
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>>>>> to try and figure it out any more. There are two patches below now. The first one uses an extra
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>>>>> argument and works. The second one tries to use %params and doesn't - take your pick :-). -- [[Will]]
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>> What do you think is best to do about `is_globlist()`? At the moment it requires that the 'second word', as
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>> 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).
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>> My thought was just to search for 'and' or 'or' as words anywhere in the pagespec. Thoughts?
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>>> Dunno, we could just finish deprecating it. Or change the regexp to
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>>> skip over spaces in parens. (`/[^\s]+\s+([^)]+)/`) --[[Joey]]
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>>>> I think I have a working regexp now.
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>> Oh, one more thing. In pagespec_translate (now pagespec_makeperl), there is a part of the regular expression for `# any other text`.
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>> This contained `()`, which has no effect. I replaced that with `\(\)`, but that is a change in the definition of pagespecs unrelated to the
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>> rest of this patch. In a related change, commands were not able to contain `)` in their parameters. I've extended that so the cannot
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>> contain `(` or `)`. -- [[Will]]
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>>> `[^\s()]+` is a character class matching all characters not spaces or
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>>> parens. Since the pervious terminals in the regexp consume most
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>>> occurances of an open paren or close paren, it's unlikely for one to
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>>> get through to that part of the regexp. For example, "foo()" will be
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>>> matched by the command matcher; "(foo)" will be matched by the open
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>>> paren literal terminal. "foo(" and "foo)" can get through to the
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>>> end, and would be matched as a page name, if it didn't exclude parens.
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>>>
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>>> So why exclude them? Well, consider "foo and(bar and baz)". We don't
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>>> want it to match "and(" as a page name!
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>>>
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>>> Escaping the parens in the character class actually changes nothing; the
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>>> changed character class still matches all characters not spaces or
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>>> parens. (Try it!).
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>>>
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>>> Re commands containing '(', I don't really see any reason not to
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>>> allow that, unless it breaks something. --[[Joey]]
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>>>> Oh, I didn't realise you didn't need to escape parens inside []. All else I
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>>>> I understood. I have stopped commands from containing parens because
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>>>> once you allow that then you might have a extra level of depth in the parsing
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>>>> of define() statements. -- [[Will]]
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>>> Updated patch. Moved the specFuncsRef to the front of the arg list. Still haven't thought through the security implications of
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>>> having it in `%params`. I've also removed all the debugging `print` statements. And I've updated the `is_globlist()` function.
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>>> I think this is ready for people other than me to have a play. It is not well enough tested to commit just yet.
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>>> -- [[Will]]
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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
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account all comments above (which doesn't mean it is above reproach :) ). --[[Will]]
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> Very belated code review of last version of the patch:
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>
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> * `is_globlist` is no longer needed
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>> Good :)
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> * I don't understand why the pagespec match regexp is changed
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> from having flags `igx` to `ixgs`. Don't see why you
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> want `.` to match '\n` in it, and don't see any `.` in the regexp
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> anyway?
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>> 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. :)
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>>> Well, I can tell you that multi-line pagespecs are supported w/o
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>>> your patch .. I use them all the time. The reason I find your
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>>> use of `/s` unlikely is because without it `\s` already matches
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>>> a newline. Only if you want to treat a newline as non-whitespace
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>>> is `/s` typically necessary. --[[Joey]]
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> * Some changes of `@_` to `%params` in `pagespec_makeperl` do not
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> make sense to me. I don't see where \%params is defined and populated,
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> except with `\$params{specFunc}`.
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>> I'm not a perl hacker. This was a mighty battle for me to get going.
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>> There is probably some battlefield carnage from my early struggles
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>> learning perl left here. Part of this is that @_ / @params already
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>> existed as a way of passing in extra parameters. I didn't want to
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>> pollute that top level namespace - just at my own parameter (a hash)
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>> which contained the data I needed.
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>>> I think I understand how the various `%params`
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>>> (there's not just one) work in your code now, but it's really a mess.
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>>> Explaining it in words would take pages.. It could be fixed by,
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>>> in `pagespec_makeperl` something like:
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>>>
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>>> my %specFuncs;
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>>> push @_, specFuncs => \%specFuncs;
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>>>
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>>> With that you have the hash locally available for populating
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>>> inside `pagespec_makeperl`, and when the `match_*` functions
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>>> are called the same hash data will be available inside their
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>>> `@_` or `%params`. No need to change how the functions are called
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>>> or do any of the other hacks.
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>>>
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>>> Currently, specFuncs is populated by building up code
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>>> that recursively calls `pagespec_makeperl`, and is then
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>>> evaluated when the pagespec gets evaluated. My suggested
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>>> change to `%params` will break that, but that had to change
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>>> anyway.
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>>>
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>>> It probably has a security hole, and is certianly inviting
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>>> one, since the pagespec definition is matched by a loose regexp (`.*`)
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>>> and then subject to string interpolation before being evaluated
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>>> inside perl code. I recently changed ikiwiki to never interpolate
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>>> user-supplied strings when translating pagespecs, and that
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>>> needs to happen here too. The obvious way, it seems to me,
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>>> is to not generate perl code, but just directly run perl code that
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>>> populates specFuncs.
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>>>> I don't think this is as bad as you make out, but your addition of the
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>>>> data array will break with the recursion my patch adds in pagespec_makeperl.
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>>>> To fix that I'll need to pass a reference to that array into pagespec_makeperl.
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>>>> I think I can then do the same thing to $params{specFuncs}. -- [[Will]]
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>>>>> You're right -- I did not think the recursive case through.
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>>>>> --[[Joey]]
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> * Seems that the only reason `match_glob` has to check for `~` is
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> because when a named spec appears in a pagespec, it is translated
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> to `match_glob("~foo")`. If, instead, `pagespec_makeperl` checked
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> for named specs, it could convert them into `check_named_spec("foo")`
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> and avoid that ugliness.
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>> 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.
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> * The changes to `match_link` seem either unecessary, or incomplete.
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> Shouldn't it check for named specs and call
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> `check_named_spec_existential`?
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>> 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
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>> 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
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>> 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.
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>>> In the common case, `match_link` does not call `match_glob`,
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>>> because the link target it is being asked to check for is a single
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>>> page name, not a glob.
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>>>> A named pagespec should fall into the glob case. These two pagespecs should be the same:
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link(a*)
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>>>> and
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define(aStar, a*) and link(~aStar)
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>>>> In the first case, we want the pagespec to match any page that links to a page matching the glob.
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>>>> In the second case, we want the pagespec to match any page that links to a page matching the named spec.
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>>>> match_link() was already doing existential part. The patches to this code were simply to remove the `lc()`
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>>>> call from the named pagespec name. Can that `lc` be removed entirely? -- [[Will]]
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>>>>> I think we could get rid of it. `bestlink` will lc it itself
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>>>>> if the uppercase version does not exist; `match_glob` matches
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>>>>> insensitively.
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>>>>> --[[Joey]]
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> * Generally, the need to modify `match_*` functions so that they
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> check for and handle named pagespecs seems suboptimal, if
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> only because there might be others people may want to use named
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> pagespecs with. It would be possible to move this check
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> to `pagespec_makeperl`, by having it check if the parameter
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> passed to a pagespec function looked like a named pagespec.
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> The only issue is that some pagespec functions take a parameter
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> that is not a page name at all, and it could be weird
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> if such a parameter were accidentially interpreted as a named
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> pagespec. (But, that seems unlikely to happen.)
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>> Possibly. I'm not sure which I prefer between the current solution and that one. Each have advantages and disadvantages.
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>> It really isn't much code for the match functions to add a call to check_named_spec_existential().
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>>> But if a plugin adds its own match function, it has
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>>> to explicitly call that code to support named pagespecs.
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>>>> Yes, and it can do that in just three lines of code. But if we automatically check for named pagespecs all the time we
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>>>> potentially break any matching function that doesn't accept pages, or wants to use multiple arguments.
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>>>>> 3 lines of code, plus the functions called become part of the API,
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>>>>> don't forget about that..
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>>>>>
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>>>>> Yes, I think that is the tradeoff, the question is whether to export
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>>>>> the additional complexity needed for that flexability.
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>>>>>
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>>>>> I'd be suprised if multiple argument pagespecs become necessary..
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>>>>> with the exception of this patch there has been no need for them yet.
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>>>>>
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>>>>> There are lots of pagespecs that take data other than pages,
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>>>>> indeed, that's really the common case. So far, none of them
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>>>>> seem likely to take data that starts with a `~`. Perhaps
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>>>>> the thing to do would be to check if `~foo` is a known,
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>>>>> named pagespec, and if not, just pass it through unchanged.
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>>>>> Then there's little room for ambiguity, and this also allows
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>>>>> pagespecs like `glob(~foo*)` to match the literal page `~foo`.
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>>>>> (It will make pagespec_merge even harder tho.. see below.)
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>>>>> --[[Joey]]
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>>>>>> I've already used multi-argument pagespec match functions in
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>>>>>> my data plugin. It is used for having different types of links. If
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>>>>>> you want to have multiple types of links, then the match function
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>>>>>> for them needs to take both the link name and the link type.
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>>>>>> I'm trying to think of a way we could have both - automatically
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>>>>>> handle the existential case unless the function indicates somehow
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>>>>>> that it'll do it itself. Any ideas? -- [[Will]]
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> * I need to check if your trick to avoid infinite recursion
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> works if there are two named specs that recursively
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> call one-another. I suspect it does, but will test this
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> myself..
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>> It worked for me. :)
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> * I also need to verify if memoizing the named pagespecs has
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> really guarded against very expensive pagespecs DOSing the wiki..
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> --[[Joey]]
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>> 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.
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>> Firstly, I'm not sure anymore that the `pagespec_merge` function will continue to work in all cases.
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>>> The problem I can see there is that if two pagespecs
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>>> get merged and both use `~foo` but define it differently,
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>>> then the second definition might be used at a point when
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>>> it shouldn't (but I haven't verified that really happens).
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>>> That could certianly be a show-stopper. --[[Joey]]
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>>>> I think this can happen in the new closure based code. I don't think this could happen in the old code. -- [[Will]]
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>>>> Even if that works, this is a good argument for having a syntactic difference between named pagespecs and normal pages.
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>>>> 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
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>>>> 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]]
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>>>>> Looks like its bracketed in the code anyway... -- [[Will]]
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>>>> Perhaps the thing to do is to have a `clear_defines()`
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>>>> function, then merging `A` and `B` yields `(A) or (clear_defines() and (B))`
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>>>> That would deal with both the cases where `A` and `B` differently
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>>>> 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]]
|
||
|
||
>>> Alternatively, my [[remove-pagespec-merge|should_optimise_pagespecs]]
|
||
>>> branch solves this, in a Gordian knot sort of way :-) --[[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 `{}`
|
||
|
||
>> Possibly :) -- [[Will]]
|
||
|
||
----
|
||
|
||
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}) {
|