X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/sod/blobdiff_plain/32f9ec0f9e8f5f5c5cef7f41c9d4609c20a47eb3..7b7947024fedb0bb7a0ea3ccb0029f6060de901b:/src/output-impl.lisp

diff --git a/src/output-impl.lisp b/src/output-impl.lisp
index f668fef..96cfa20 100644
--- a/src/output-impl.lisp
+++ b/src/output-impl.lisp
@@ -62,8 +62,20 @@ (defmethod add-sequencer-item-function ((sequencer sequencer) name function)
     (pushnew function (sequencer-item-functions item))))
 
 (defmethod invoke-sequencer-items ((sequencer sequencer) &rest arguments)
-  (dolist (item (merge-lists (reverse (sequencer-constraints sequencer))))
-    (dolist (function (reverse (sequencer-item-functions item)))
-      (apply function arguments))))
+  #+debug
+  (format *debug-io* "~@<;; ~@;Constraints: ~_~
+		      ~<~@{~<  * ~;~@{~S~^, ~:_~}~:>~:@_~}~:>~:>"
+	  (mapcar (lambda (constraint)
+		    (mapcar #'sequencer-item-name constraint))
+		  (sequencer-constraints sequencer)))
+  (let ((seen (make-hash-table)))
+    (dolist (item (merge-lists (reverse (sequencer-constraints sequencer))))
+      (setf (gethash item seen) t)
+      (dolist (function (reverse (sequencer-item-functions item)))
+	(apply function arguments)))
+    (maphash (lambda (name item)
+	       (unless (gethash item seen)
+		 (warn "Unused output item ~S" name)))
+	     (sequencer-table sequencer))))
 
 ;;;----- That's all, folks --------------------------------------------------