def optional_rows

bendvy-ecs-core@0.1.0.4 · inspector_query.bend:73

import Base
import inspector_query_projection.bend as Q

73def optional_rows(~S:Data,~V:Data,rows:List<&2,Q.Row<S,V>>) -> Result<&2,&2,SingleError,Maybe<&2,Q.Row<S,V>>>:
74  match rows:
75    case []:Done{None{}}
76    case row <> []:Done{Some{row}}
77    case _ <> _ <> rest:Fail{MultipleEntities{Nat.add(2n,List.length(&2,Q.Row<S,V>,rest))}}