! Copyright (C) 2008 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
-USING: kernel assocs accessors ;
+USING: kernel assocs accessors summary ;
IN: biassocs
TUPLE: biassoc from to ;
M: biassoc set-at
[ from>> set-at ] [ swapd to>> once-at ] 3bi ;
+ERROR: no-biassoc-deletion ;
+
+M: no-biassoc-deletion summary
+ drop "biassocs do not support deletion" ;
+
M: biassoc delete-at
- "biassocs do not support deletion" throw ;
+ no-biassoc-deletion ;
M: biassoc >alist
from>> >alist ;