X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/48457b6ce3a783b68549ea4fa63b222d28663fe5..f97f102b04e7ae67bd3db5320dd34496309de5fe:/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 b8c5b8f20..417d5910e 100644 --- a/doc/todo/tracking_bugs_with_dependencies.mdwn +++ b/doc/todo/tracking_bugs_with_dependencies.mdwn @@ -12,7 +12,7 @@ I like the idea of [[tips/integrated_issue_tracking_with_ikiwiki]], and I do so >> I thought about this briefly, and got about that far.. glad you got >> further. :-) --[[Joey]] ->> Or, one could also refer to the language of [[!wikipedia description logics]]: their formulas actually define classes of objects through quantified relations to other classes. --Ivan Z. +>> 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. @@ -60,6 +60,7 @@ I like the idea of [[tips/integrated_issue_tracking_with_ikiwiki]], and I do so >> So, equivilant example: `define(bugs, bugs/* and !*/Discussion) and define(openbugs, bugs and !link(done)) and openbugs and !link(openbugs)` >> + >> Re recursion, it is avoided.. but building a pagespec that is O(N^X) where N is the >> number of pages in the wiki is not avoided. Probably need to add DOS prevention. >> --[[Joey]] @@ -192,6 +193,141 @@ The following three inlines work for me with this patch: 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. + +> * 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. + +> * 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. + +> * 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]] + +>> 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]] + ---- diff --git a/IkiWiki.pm b/IkiWiki.pm