1	import Base
2	import ./execution_query_matches.bend as Q
3	import ./lifecycle.bend as Life
4	
5	type Lookup<-V:Data> is Data:
6	  OutsideDomain{}
7	  Known{view:Maybe<&2,V>}
8	def cached_lookup_here(-V:Data,view:Maybe<&2,V>,next:Lookup<V>,found:Bool) -> Lookup<V>:
9	  match found:
10	    case False{}:next
11	    case True{}:Known{view}
12	def cached_lookup(-V:Data,rows:List<&2,Q.Row<V>>,+offset:U32) -> Lookup<V>:
13	  match rows:
14	    case []:OutsideDomain{}
15	    case +row <> rest:cached_lookup_here(V,Q.row_view(V,row),cached_lookup(V,rest,offset),U32.is_eq(Q.row_offset(V,row),offset))
16	def cached_stamp(-V:Data,rows:List<&2,Q.Row<V>>,+index:U32) -> Life.Stamp:
17	  match rows:
18	    case []:Life.Stamp{None{},None{}}
19	    case +row <> rest:Life.choose(U32.is_eq(index,Q.row_offset(V,row)),Q.row_stamp(V,row),cached_stamp(V,rest,index))