YS
генерилки фильтров/пагинаций для запросов к бд
reqextractor :: (Int16, Text, Text) -> Requirement
reqextractor (a,b,c) = Requirement a b c
requirement :: Value Requirement
requirement = fmap reqextractor (composite ((,,) <$> (field . nonNullable) int2 <*> (field . nonNullable) text <*> (field . nonNullable) text))
restextractor :: (Text, [Requirement]) -> Restrictor
restextractor (a,b) = Restrictor a b
restrictor :: Value Restrictor
restrictor = fmap restextractor (composite ((,) <$> (field . nonNullable) text <*> (field . nonNullable) (array (dimension replicateM (element (nonNullable requirement))))))
clusterextractor :: (Int16, Text, [Restrictor]) -> Cluster
clusterextractor (a,b,c) = Cluster a b c
cluster :: Value Cluster
cluster = fmap clusterextractor (composite ((,,) <$> (field . nonNullable) int2 <*> (field . nonNullable) text <*> (field . nonNullable) (array (dimension replicateM (element (nonNullable restrictor))))))
clusterDecoder :: Result Cluster
clusterDecoder = singleRow $ column (nonNullable cluster)
и бд:
cluster_id | cluster_name | restrictors
------------+--------------+---------------------------------------------------------------
1 | for math | {"(\"Advanced Level GCE\",\"{\"\"(8,Mathematics,A*)\"\"}\")"}