over 0accumulate-as ; inline
: occurrence-count-by ( seq quot: ( elt -- elt' ) -- hash seq' )
- '[ nip @ over inc-at* ] H{ } clone -rot 0accumulate ; inline
+ '[ nip @ over inc-at* ] [ H{ } clone ] 2dip 0accumulate ; inline
: occurrence-count ( seq -- hash seq' )
[ ] occurrence-count-by ; inline