func NewIndexNest(keyspace datastore.Keyspace, nest *algebra.IndexNest, index datastore.Index, covers expression.Covers) *IndexNest { rv := &IndexNest{ keyspace: keyspace, term: nest.Right(), outer: nest.Outer(), keyFor: nest.For(), index: index, covers: covers, } rv.idExpr = expression.NewField( expression.NewMeta(expression.NewIdentifier(rv.keyFor)), expression.NewFieldName("id", false)) return rv }