def composed_optional_rows

bendvy-ecs-core@0.1.0.4 · inspector_query.bend:141

import Base

141def composed_optional_rows(~S:Data,~V:Data,rows:List<&2,ProjectedRow<S,V>>) -> Result<&2,&2,SingleError,Maybe<&2,ProjectedRow<S,V>>>:
142  match rows:
143    case []:Done{None{}}
144    case row <> []:Done{Some{row}}
145    case _ <> _ <> rest:Fail{MultipleEntities{Nat.add(2n,List.length(&2,ProjectedRow<S,V>,rest))}}