Add finder unknown keywords.

* finder.el (finder-unknown-keywords): New function.

* info.el (Info-finder-find-node): Use `finder-unknown-keywords'
to create a Finder node with unknown keywords.

1 files changed, 23 insertions, 1 deletions

diff --git a/lisp/finder.el b/lisp/finder.el
index b1e67908d1a..358c0a1fee2 100644
--- a/lisp/finder.el
+++ b/lisp/finder.el
@@ -33,7 +33,6 @@
 ;; there doesn't seem to be any way to get completing-read to exit on
 ;; an EOL with no substring pending, which is what we'd want to end the loop.
 ;;    2. Search by string in synopsis line?
-;;    3. Function to check finder-package-info for unknown keywords.
 
 ;;; Code:
 
@@ -230,6 +229,29 @@ no arguments compiles from `load-path'."
      '(mouse-face highlight
 		  help-echo finder-help-echo))))
 
+(defun finder-unknown-keywords ()
+  "Return an alist of unknown keywords and number of their occurences.
+Unknown are keywords that are present in `finder-package-info'
+but absent in `finder-known-keywords'."
+  (let ((unknown-keywords-hash (make-hash-table)))
+    ;; Prepare a hash where key is a keyword
+    ;; and value is the number of keyword occurences.
+    (mapc (lambda (package)
+	    (mapc (lambda (keyword)
+		    (unless (assq keyword finder-known-keywords)
+		      (puthash keyword
+			       (1+ (gethash keyword unknown-keywords-hash 0))
+			       unknown-keywords-hash)))
+		  (nth 2 package)))
+	  finder-package-info)
+    ;; Make an alist from the hash and sort by the keyword name.
+    (sort (let (unknown-keywords-list)
+	    (maphash (lambda (key value)
+		       (push (cons key value) unknown-keywords-list))
+		     unknown-keywords-hash)
+	    unknown-keywords-list)
+	  (lambda (a b) (string< (car a) (car b))))))
+
 ;;;###autoload
 (defun finder-list-keywords ()
   "Display descriptions of the keywords in the Finder buffer."