3.3.2 Scoping Rules by Feed

“title”, “content”, “title-or-content” & “authors” rules can also be scoped by feed; that is, you can arrange to have such rules only apply to entries from certain feeds (or apply only to entries not from certain feeds) (see Types of Rules).

Each of these rule types reserves a slot in their definiotn for “feed scope rules”. Such fules are expressed as a cons cell:

(boolean . ((attr match-type matex-text)...))

The car is a boolean, and the cdr is a list of feed selectors. If the former is t, the rule will only be applied if the entry’s feed matches at least one of the selectors listed. If the boolean value is nil, the rule will only apply if the entry’s feed matches none of the selectors listed.

Each selector is itself a three-tuple consisting of:

  1. Feed attribute One of the symbols t, u or a for title, URL, or author respectively; this determines the attribute of the feed against which this rule’s text will be matched.
  2. Match type The match type as per above.
  3. Match text

Example:

("title"
  (:text "foo" :value 100 :type s
   :feeds (t . ((t S "Bar")))))

This defines a title rule See title Rules that checks for a substring matching “foo” in the entry title and adds 100 points to its score on match. However, it will only match entries originating from feeds whose title contains the string “Bar” (case-sensitive).