X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/6f8632184ebc66154c9280aff3b84041d056d52e..0e72550870ed51aa6aee57e08f63edf0b07befc0:/doc/todo/tracking_bugs_with_dependencies.mdwn diff --git a/doc/todo/tracking_bugs_with_dependencies.mdwn b/doc/todo/tracking_bugs_with_dependencies.mdwn index bdc085785..3a761731b 100644 --- a/doc/todo/tracking_bugs_with_dependencies.mdwn +++ b/doc/todo/tracking_bugs_with_dependencies.mdwn @@ -9,6 +9,11 @@ I like the idea of [[tips/integrated_issue_tracking_with_ikiwiki]], and I do so > One way to do this would be to introduce variables into the pagespec, along with > universal and/or existential [[!wikipedia Quantification]]. That looks quite complex. > +>> I thought about this briefly, and got about that far.. glad you got +>> further. :-) --[[Joey]] + +>> 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. > I could pass a pagespec to `link()` and that would return true if there is a link to any @@ -22,6 +27,9 @@ I like the idea of [[tips/integrated_issue_tracking_with_ikiwiki]], and I do so > ends, and that isn't a regular language (we can't use regular expression matching for > easy parsing). > +>> Also, it may cause ambiguities with page names that contain parens +>> (though some such ambigutities already exist with the pagespec syntax). +> > One simplification of that would be to introduce some pagespec [[shortcuts]]. We could > then allow pagespec functions to take either pages, or named pagespec shortcuts. The > pagespec shortcuts would just be listed on a special page, like current [[shortcuts]]. @@ -37,9 +45,707 @@ I like the idea of [[tips/integrated_issue_tracking_with_ikiwiki]], and I do so > > -- [[Will]] -> One quick further thought. All the above discussion assumes that 'dependency' is the +>> Having a separate page for the shortcuts feels unwieldly.. perhaps +>> instead the shortcut could be defined earlier in the scope of the same +>> pagespec that uses it? +>> +>> Example: `define(~bugs, bugs/* and !*/Discussion) and define(~openbugs, ~bugs and !link(done)) and ~openbugs and !link(~openbugs)` + +>>> That could work. parens are only ever nested 1 deep in that grammar so it is regular and the current parsing would be ok. + +>> Note that I made the "~" explicit, not implicit, so it could be left out. In the case of ambiguity between +>> a definition and a page name, the definition would win. + +>>> That was my initial thought too :), but when implementing it I decided that requiring the ~ made things easier. I'll probably require the ~ for the first pass at least. + +>> So, equivilant example: `define(bugs, bugs/* and !*/Discussion) and define(openbugs, bugs and !link(done)) and openbugs and !link(openbugs)` +>> + +>> Re recursion, it is avoided.. but building a pagespec that is O(N^X) where N is the +>> number of pages in the wiki is not avoided. Probably need to add DOS prevention. +>> --[[Joey]] + +>>> If you memoize the outcomes of the named pagespecs you can make in O(N.X), no? +>>> -- [[Will]] + +>>>> Yeah, guess that'd work. :-) + +> One quick further thought. All the above discussion assumes that 'dependency' is the > same as 'links to', which is not really true. For example, you'd like to be able to say > "This bug does not depend upon [ [ link to other bug ] ]" and not have a dependency. > Without having different types of links, I don't see how this would be possible. > > -- [[Will]] + +>> 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. + +At the moment I've added a new preprocessor plugin, `definepagespec`, which is like +shortcut for pagespecs. To reference a named pagespec, use `~` like this: + + [ [!definepagespec name="bugs" spec="bugs/* and !*/Discussion"]] + [ [!definepagespec name="openbugs" spec="~bugs and !link(done)"]] + [ [!definepagespec name="readybugs" spec="~openbugs and !link(~openbugs)"]] + +At the moment the problem is in `match_link()` when we're trying to find a sub-page that +matches the appropriate page spec. There is no good list of pages available to iterate over. + + foreach my $nextpage (keys %IkiWiki::pagesources) + +does not give me a good list of pages. I found the same thing when I was working on +this todo [[todo/Add_a_plugin_to_list_available_pre-processor_commands]]. + +> I'm not sure why iterating over `%pagesources` wouldn't work here, it's the same method +> used by anything that needs to match a pagespec against all pages..? --[[Joey]] + +>> My uchecked hypothesis is that %pagesources is created after the refresh hook. +>> I've also been concerned about how globally defined pagespec shortcuts would interact with +>> the page dependancy system. Your idea of internally defined shortcuts should fix that. -- [[Will]] + +>>> You're correct, the refresh hook is run very early, before pagesources +>>> is populated. (It will be partially populated on a refresh, but will +>>> not be updated to reflect new pages.) Agree that internally defined +>>> seems the way to go. --[[Joey]] + +Immediately below is a patch which seems to basically work. Lots of debugging code is still there +and it needs a cleanup, but I thought it worth posting at this point. (I was having problems +with old style glob lists, so i just switched them off for the moment.) + +The following three inlines work for me with this patch: + + Bugs: + + [ [!inline pages="define(~bugs, bugs/* and ! */Discussion) and ~bugs" archive="yes"]] + + OpenBugs: + + [ [!inline pages="define(~bugs, bugs/* and ! */Discussion) and define(~openbugs,~bugs and !link(done)) and ~openbugs" archive="yes"]] + + ReadyBugs: + + [ [!inline pages="define(~bugs, bugs/* and ! */Discussion) and define(~openbugs,~bugs and !link(done)) and define(~readybugs,~openbugs and !link(~openbugs)) and ~readybugs" archive="yes"]] + +> Nice! Could the specfuncsref be passed in %params? I'd like to avoid +> needing to change the prototype of every pagespec function, since several +> plugins define them too. --[[Joey]] + +>> Maybe - it needs more thought. I also considered it when I was going though changing all those plugins :). +>> My concern was that `%params` can contain other user-defined parameters, +>> e.g. `link(target, otherparameter)`, and that means that the specFuncs could be clobbered by a user (or other +>> weird security hole). I thought it better to separate it, but I didn't think about it too hard. I might move it to +>> the first parameter rather than the second. Ikiwiki is my first real perl hacking and I'm still discovering +>> good ways to write things in perl. +>> +>>>> `%params` contains the parameters passed to `pagespec_match`, not +>>>> user-supplied parameters. The user-supplied parameter to a function +>>>> like `match_glob()` or `match_link()` is passed in the second positional parameter. --[[Joey]] + +>>>>> OK. That seems reasonable then. The only problem is that my PERLfu is not strong enough to make it +>>>>> work. I really have to wonder what substance was influencing the designers of PERL... +>>>>> I can't figure out how to use the %params. And I'm pissed off enough with PERL that I'm not going +>>>>> to try and figure it out any more. There are two patches below now. The first one uses an extra +>>>>> argument and works. The second one tries to use %params and doesn't - take your pick :-). -- [[Will]] + +>> What do you think is best to do about `is_globlist()`? At the moment it requires that the 'second word', as +>> delimited by a space and ignoring parens, is 'and' or 'or'. This doesn't hold in the above example pagespecs (so I just hard wired it to 0 to test my patch). +>> My thought was just to search for 'and' or 'or' as words anywhere in the pagespec. Thoughts? + +>>> Dunno, we could just finish deprecating it. Or change the regexp to +>>> skip over spaces in parens. (`/[^\s]+\s+([^)]+)/`) --[[Joey]] + +>>>> I think I have a working regexp now. + +>> Oh, one more thing. In pagespec_translate (now pagespec_makeperl), there is a part of the regular expression for `# any other text`. +>> This contained `()`, which has no effect. I replaced that with `\(\)`, but that is a change in the definition of pagespecs unrelated to the +>> rest of this patch. In a related change, commands were not able to contain `)` in their parameters. I've extended that so the cannot +>> contain `(` or `)`. -- [[Will]] + +>>> `[^\s()]+` is a character class matching all characters not spaces or +>>> parens. Since the pervious terminals in the regexp consume most +>>> occurances of an open paren or close paren, it's unlikely for one to +>>> get through to that part of the regexp. For example, "foo()" will be +>>> matched by the command matcher; "(foo)" will be matched by the open +>>> paren literal terminal. "foo(" and "foo)" can get through to the +>>> end, and would be matched as a page name, if it didn't exclude parens. +>>> +>>> So why exclude them? Well, consider "foo and(bar and baz)". We don't +>>> want it to match "and(" as a page name! +>>> +>>> Escaping the parens in the character class actually changes nothing; the +>>> changed character class still matches all characters not spaces or +>>> parens. (Try it!). +>>> +>>> Re commands containing '(', I don't really see any reason not to +>>> allow that, unless it breaks something. --[[Joey]] + +>>>> Oh, I didn't realise you didn't need to escape parens inside []. All else I +>>>> I understood. I have stopped commands from containing parens because +>>>> once you allow that then you might have a extra level of depth in the parsing +>>>> of define() statements. -- [[Will]] + +>>> Updated patch. Moved the specFuncsRef to the front of the arg list. Still haven't thought through the security implications of +>>> having it in `%params`. I've also removed all the debugging `print` statements. And I've updated the `is_globlist()` function. +>>> I think this is ready for people other than me to have a play. It is not well enough tested to commit just yet. +>>> -- [[Will]] + +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]] + +>> 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}) {