From 61105cca4f219323a0b490e6251ac60abc549c2a Mon Sep 17 00:00:00 2001 From: "http://www.cse.unsw.edu.au/~willu/" Date: Thu, 8 Oct 2009 01:33:23 -0400 Subject: [PATCH] Questions... --- doc/todo/dependency_types.mdwn | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/doc/todo/dependency_types.mdwn b/doc/todo/dependency_types.mdwn index 3bb1b5452..01205f178 100644 --- a/doc/todo/dependency_types.mdwn +++ b/doc/todo/dependency_types.mdwn @@ -222,7 +222,7 @@ ShavedByBob.mdwn: Does ShavedByBob.mdwn include itself? -(Yeah - in IkiWiki currently links are included by include, but the idea holds. I had a good example a while back, but I can't think of it right now.) +(Yeah - in IkiWiki currently links are *not* included by include, but the idea holds. I had a good example a while back, but I can't think of it right now.) sigh. @@ -232,6 +232,10 @@ sigh. > to determine what metadata, pages, etc they depend on. It is indeed > tricky to do. More thoughts on influence lists a bit below. --[[Joey]] +>> The big part of what makes this tricky is that there may be cycles in the +>> dependency graph. This can lead to situations where the result is just not +>> well defined. This is what I was trying to get at above. -- [[Will]] + ---- ### Link dependencies @@ -304,6 +308,20 @@ changes, is needed. I'm using this term for the concept of a list of pages whose modification can indirectly influence what pages a pagespec matches. +> Trying to make a formal definition of this: (Note, I'm using the term sets rather than lists, but they're roughly equivalent) +> +> * Let the *matching set* for a pagespec be the set of pages that the pagespec matches. +> * Let a *complete influence set* for a pagespec be the set of all pages whose alteration might change the matching set of that pagespec. +> * Let the *direct influence set* be the intersection of the matching set and the complete influence set. +> * Let the *indirect influence set* be the compliment of the direct influence set with respect to the complete influence set. +> +> Is that a fair definition? I don't think it quite matches your examples below unfortunately. +> I was unsure if I should insert the word 'existing' in there in a few places. As it stands, these definitions could include sets of pages that don't exist, e.g. "*". +> The one I'm least sure of is the definition of the direct influence set. It feels like you want something +> like "the traditional set of things we thought about that could cause a pagespec to change", but that definition +> is not very formal and I suspect will lead to problems. Something like "The set of pages matched by the globs in the pagespec" might be closer? +> --[[Will]] + #### Examples * The pagespec "created_before(foo)" has an influence list that contains foo. @@ -331,6 +349,10 @@ can indirectly influence what pages a pagespec matches. remove a link and make it not match any more, and so the list is needed due to the removal problem. +>> Why doesn't this include every page? If I change a page that doesn't have a link to +>> 'done' to include a link to 'done', then it will now match... or is that considered a +>> 'direct match'? -- [[Will]] + #### Low-level Calculation One way to calculate a pagespec's influence would be to @@ -421,3 +443,8 @@ Note that influences can also have types, same as dependency types. For example, "backlink(foo)" has an influence of foo, of type links. "created_before(foo)" also is influenced by foo, but it's a presence type. Etc. + +> This is an interesting concept that I hadn't considered. It might +> allow significant computational savings, but I suspect will be tricky +> to implement. -- [[Will]] + -- 2.44.0