: record-renaming ( from to -- )
2array renaming-set get push needs-renaming? on ;
-:: (compute-renaming-set) ( vreg required quot: ( vreg preferred required -- ) -- )
+:: (compute-renaming-set) ( ..a vreg required quot: ( ..a vreg preferred required -- ..b ) -- ..b )
vreg rep-of :> preferred
preferred required eq?
[ vreg no-renaming ]