X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/f977eaf39493984924b6ae9409be3e1d504fc0ae..09ed5e00d2118618460e5c23fcde3f10b09984a5:/doc/todo/dependency_types.mdwn

diff --git a/doc/todo/dependency_types.mdwn b/doc/todo/dependency_types.mdwn
index 6ca06fdab..4db633ead 100644
--- a/doc/todo/dependency_types.mdwn
+++ b/doc/todo/dependency_types.mdwn
@@ -280,6 +280,7 @@ sigh.
   that the page links to, which is just what link dependencies are
   triggered on.
 
+[[done]]
 ----
 
 ### the removal problem
@@ -408,6 +409,11 @@ can indirectly influence what pages a pagespec matches.
 >>>> find changes in deleted pages. (I verified this works by experiment,
 >>>> also that `created_after` is triggered by a deleted page.) --[[Joey]]
 
+>>>>> Oh, okie.  I looked at the source, saw the `if (exists $IkiWiki::pagectime{$testpage})` and assumed it would fail.
+>>>>> Of course, having it succeed doesn't cure all the issues -- just moves them.  With `created_before()` succeeding
+>>>>> for deleted files, this pagespec will be match any removal in the entire wiki with the base mechanism.  Whether this is
+>>>>> better or worse than the longer indirect influence list is an empirical question. -- [[Will]]
+
 * The pagespec "foo" has an empty influence list. This is because a
   modification/creation/removal of foo directly changes what the pagespec
   matches.
@@ -547,73 +553,16 @@ operators. Currently, this turns into roughly:
 `FailReason() & SuccessReason(patch)`
 
 Let's say that the glob instead returns a HardFailReason, which when
-ANDed with another object, drops their influences. (But when ORed, combines
-them.) Fixes the above, but does it always work?
-
-"(bugs/* or link(patch)) and backlink(index)" =>
-`( HardFailReason() | SuccessReason(page) ) & SuccessReason(index)`` =>
-`SuccessReason(page & SuccessReason(index)` =>
-SuccessReason(page, index) => right
-
-"(bugs/* and link(patch)) or backlink(index)" =>
-`( HardFailReason() & SuccessReason(page) ) | SuccessReason(index)`` =>
-`HardFailReason() | SuccessReason(index)` =>
-`SuccessReason(index)` => right
-
-"!bugs/* and link(patch)" =>
-`HardFailReason() | SuccessReason(bugs/foo)` =>  
-`HardFailReason()` => right
-
-#### High-level Calculation and Storage
-
-Naively calculating the full influence list for a pagespec requires trying
-to match it against every page in the wiki. I'd like to avoid doing such
-expensive matching redundantly.
-
-It may be possible, for some types of pagespecs, to just try matching a
-single, arbitrary page against it, and know the full influence list has
-been obtained. It seems to be that case that if a pagespec has any
-influences, matching any page will return at least one. So if none are
-returned, we can skip trying other pages.
-
-If the influence list does not include the page that was tried, we know
-that the pagespec does not things like `link()` and `title()`, that are
-influenced by the page's own content. So it *might* be safe to not try
-matching any more pages in this case too. I think it would work for all
-current pagespec terms. There might be a hypothetical term where this
-optimisation doesn't work. We could add a special case to ensure it can
-work: If a term declares it is unfluenced by "", then it means it is
-always influenced by the matching page.
-
-Anyway, this seems worth doing: Add a `pagespec_match_all`, which returns a
-list of all pages in the whole wiki that match the pagespec, and also adds
-the pagespec as a dependency, and while it's at it, calculates and stores
-the influence list.
-
-It could have an optional sort parameter, and limit parameter, to control
-how many items to return and the sort order. So when inline wants to
-display the 10 newest, only the influence lists for those ten are added.
-
-If `pagespec_match_depends` can be used by all plugins, then great,
-influences are automatically calculated, no extra work needs to be done.
-
-If not, and some plugins still need to use `pagespec_match_list` or
-`pagespec_match`, and `add_depends`, then I guess that `add_depends` can do
-a slightly more expensive influence calculation.
-
-Bonus: If `add_depends` is doing an influence calculation, then I can remove
-the nasty hack it currently uses to decide if a given pagespec is safe to use
-with an existence or links dependency.
-
-Where to store the influence list? Well, it appears that we can just add
-(content) dependencies for each item on the list, to the page's
-regular list of simple dependencies. So, the data stored ends up looking
-just like what is stored today by the explicit dependency hacks. Except,
-it's calculated more smartly, and is added automatically.
-
-> I've implemented influence calculation in `add_depends`. As expected,
-> it means rather a lot more work, and makes some things much slower.
-> Optimisations next.. --[[Joey]] 
+ANDed with another object, blocks their influences. (But when ORed,
+combines them.)
+
+Question: Are all pagespec terms that return reason objects w/o any
+influence info, suitable to block influence in this way? 
+
+To be suitable to block, a term should never change from failing to match a
+page to successfully matching it, unless that page is directly changed in a
+way that influences are not needed for ikiwiki to notice. But, if a term
+did not meet these criteria, it would have an influence. QED.
 
 #### Influence types