[[!tag patch patch/core]] I like the idea of [[tips/integrated_issue_tracking_with_ikiwiki]], and I do so on several wikis. However, as far as I can tell, ikiwiki has no functionality which can represent dependencies between bugs and allow pagespecs to select based on dependencies. For instance, I can't write a pagespec which selects all bugs with no dependencies on bugs not marked as done. --[[JoshTriplett]] > I started having a think about this. I'm going to start with the idea that expanding > the pagespec syntax is the way to attack this. It seems that any pagespec that is going > to represent "all bugs with no dependencies on bugs not marked as done" is going to > need some way to represent "bugs not marked as done" as a collection of pages, and > then represent "bugs which do not link to pages in the previous collection". > > One way to do this would be to introduce variables into the pagespec, along with > universal and/or existential [[!wikipedia Quantification]]. That looks quite complex. > >> I thought about this briefly, and got about that far.. glad you got >> further. :-) --[[Joey]] >> 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 > page matching the pagespec. This makes the variables and existential quantification > implicit. It would allow the example requested above: > >> `bugs/* and !*/Discussion and !link(bugs/* and !*/Discussion and !link(done))` > > Unfortunately, this is also going to make the pagespec parsing more complex because > we now need to parse nested sets of parentheses to know when the nested pagespec > ends, and that isn't a regular language (we can't use regular expression matching for > easy parsing). > >> Also, it may cause ambiguities with page names that contain parens >> (though some such ambigutities already exist with the pagespec syntax). > > One simplification of that would be to introduce some pagespec [[shortcuts]]. We could > then allow pagespec functions to take either pages, or named pagespec shortcuts. The > pagespec shortcuts would just be listed on a special page, like current [[shortcuts]]. > (It would probably be a good idea to require that shortcuts on that page can only refer > to named pagespecs higher up that page than themselves. That would stop some > looping issues...) These shortcuts would be used as follows: when trying to match > a page (without globs) you look to see if the page exists. If it does then you have a > match. If it doesn't, then you look to see if a similarly named pagespec shortcut > exists. If it does, then you check that pagespec recursively to see if you have a match. > The ordering requirement on named pagespecs stops infinite recursion. > > Does that seem like a reasonable first approach? > > -- [[Will]] >> Having a separate page for the shortcuts feels unwieldly.. perhaps >> instead the shortcut could be defined earlier in the scope of the same >> pagespec that uses it? >> >> Example: `define(~bugs, bugs/* and !*/Discussion) and define(~openbugs, ~bugs and !link(done)) and ~openbugs and !link(~openbugs)` >>> That could work. parens are only ever nested 1 deep in that grammar so it is regular and the current parsing would be ok. >> Note that I made the "~" explicit, not implicit, so it could be left out. In the case of ambiguity between >> a definition and a page name, the definition would win. >>> That was my initial thought too :), but when implementing it I decided that requiring the ~ made things easier. I'll probably require the ~ for the first pass at least. >> So, equivilant example: `define(bugs, bugs/* and !*/Discussion) and define(openbugs, bugs and !link(done)) and openbugs and !link(openbugs)` >> >> Re recursion, it is avoided.. but building a pagespec that is O(N^X) where N is the >> number of pages in the wiki is not avoided. Probably need to add DOS prevention. >> --[[Joey]] >>> If you memoize the outcomes of the named pagespecs you can make in O(N.X), no? >>> -- [[Will]] >>>> Yeah, guess that'd work. :-) > One quick further thought. All the above discussion assumes that 'dependency' is the > same as 'links to', which is not really true. For example, you'd like to be able to say > "This bug does not depend upon [ [ link to other bug ] ]" and not have a dependency. > Without having different types of links, I don't see how this would be possible. > > -- [[Will]] >> 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]] >>> 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}) {