@@ -21,10 +21,11 @@
 
 ;; Provides common helper functions used throughout the project
 
 (provide maybe-meta     ; Select from (current-metas) or default value ("") if not available
          maybe-attr     ; Return an attribute’s value or a default ("") if not available
+         set-meta!
          here-output-path
          here-source-path
          here-id
          listing-context
          current-series-noun    ; Retrieve noun-singular from current 'series meta, or #f
@@ -62,10 +63,15 @@
 
 (define (maybe-meta m [missing ""])
   (cond [(current-metas) (or (select-from-metas m (current-metas)) missing)]
         [else missing]))
 
+(define (set-meta! key v)
+  (define cur-metas (current-metas))
+  (and cur-metas
+       (current-metas (hash-set! cur-metas key v))))
+
 ;; Return the current source path, relative to (current-project-root)
 (define (here-source-path)
   (match (current-metas)
     [(? hash? m)
      (define-values (_ rel-path-parts)