! Based on Clojure's PersistentHashMap by Rich Hickey.
-USING: math math.bitwise arrays kernel accessors locals sequences
-sequences.private
-persistent.sequences
-persistent.hashtables.config
-persistent.hashtables.nodes ;
+USING: accessors kernel math math.bitwise
+persistent.hashtables.config persistent.hashtables.nodes
+persistent.sequences sequences sequences.private ;
IN: persistent.hashtables.nodes.bitmap
: index ( bit bitmap -- n ) [ 1 - ] dip bitand bit-count ; inline