@@ -16,10 +16,11 @@
 (require pollen/setup
          pollen/core
          pollen/template
          racket/string
          racket/function
+         racket/list
          txexpr
          db/base
          "sqlite-tools.rkt"
          "snippets-html.rkt"
          "dust.rkt")
@@ -332,11 +333,22 @@
 (define (article-plain-title pagenode)
   (query-value (sqltools:dbc) "SELECT `title_plain` FROM `articles` WHERE `pagenode` = ?1" (symbol->string pagenode)))
 
 ;; ~~~ Keyword Index Entries ~~~
 
-;; (private) Save any index entries in doc to the cache
+;; (private) Convert an entry key into a list of at most two elements,
+;; a main entry and a sub-entry.
+;;   "entry" → '("entry" "")
+;;   "entry!sub" → '("entry" "sub")
+;;   "entry!sub!why?!? '("entry" "sub")
+(define (split-entry str)
+  (define splits (string-split str "!"))
+  (list (car splits)
+        (cadr (append splits (list "")))))
+
+;; (private) Save any index entries in doc to the SQLite cache
+;; Sub-entries are specified by "!" in the index key
 (define (crystalize-index-entries! pagenode doc)
   (define (index-entry? tx)
     (and (txexpr? tx)
          (string=? "index-link" (attr-ref tx 'class "")) ; see definition of html-index
          (attr-ref tx 'data-index-entry #f)))
@@ -346,12 +358,13 @@
   (query! "DELETE FROM `keywordindex` WHERE `pagenode` = ?1" (symbol->string pagenode))
   
   (unless (null? entries)
     (define entry-rows
       (for/list ([entry-tx (in-list entries)])
-        (list (attr-ref entry-tx 'data-index-entry)
-              "" ; subentries not yet implemented
+        (define entry-parts (split-entry (attr-ref entry-tx 'data-index-entry)))
+        (list (first entry-parts)
+              (second entry-parts)
               (symbol->string pagenode)
               (attr-ref entry-tx 'id))))
     (query! (make-insert-rows-query "keywordindex" table_keywordindex-fields entry-rows))))
 
 ;; ~~~ Series ~~~