Fix warnings, lint, and ambiguous hasql imports

src/PgStructure.hs

@@ -3,25 +3,20 @@
 module PgStructure where
 
 import PgQuery (QualifiedTable(..))
-import Data.Functor ( (<$>) )
 import Data.Text hiding (foldl, map, zipWith, concat)
 import Data.Aeson
 import Data.Functor.Identity
-import qualified Data.Vector as V
 import Data.String.Conversions (cs)
 
-import Control.Applicative ( (<*>) )
-
 import qualified Data.List as L
 import qualified Data.Map as Map
 
 import qualified Hasql as H
-import qualified Hasql.Backend as H hiding (Tx)
-import qualified Hasql.Postgres as H
+import qualified Hasql.Postgres as P
 
-foreignKeys :: QualifiedTable -> H.Tx H.Postgres s (Map.Map Text ForeignKey)
+foreignKeys :: QualifiedTable -> H.Tx P.Postgres s (Map.Map Text ForeignKey)
 foreignKeys table = do
-  r :: [(Text, Text, Text)] <- H.listEx $ [H.stmt|
+  r <- H.listEx $ [H.stmt|
       select kcu.column_name, ccu.table_name AS foreign_table_name,
         ccu.column_name AS foreign_column_name
       from information_schema.table_constraints AS tc
@@ -36,61 +31,65 @@ foreignKeys table = do
 
   return $ foldl addKey Map.empty r
   where
-    addKey m (col, ftab, fcol) = Map.insert col (ForeignKey (cs ftab) (cs fcol)) m
+    addKey :: Map.Map Text ForeignKey -> (Text, Text, Text) -> Map.Map Text ForeignKey
+    addKey m (col, ftab, fcol) = Map.insert col (ForeignKey ftab fcol) m
 
 
-tables :: Text -> H.Tx H.Postgres s [Table]
-tables schema =
-  map table <$> (H.listEx $ [H.stmt|
+tables :: Text -> H.Tx P.Postgres s [Table]
+tables schema = do
+  rows <- H.listEx $
+    [H.stmt|
       select table_schema, table_name,
              is_insertable_into
         from information_schema.tables
        where table_schema = ?
        order by table_name
-    |] schema)
+    |] schema
+  return $ map tableFromRow rows
 
 
-columns :: QualifiedTable -> H.Tx H.Postgres s [Column]
+columns :: QualifiedTable -> H.Tx P.Postgres s [Column]
 columns table = do
   cols <- H.listEx $ [H.stmt|
-    select info.table_schema as schema, info.table_name as table_name,
-           info.column_name as name, info.ordinal_position as position,
-           info.is_nullable as nullable, info.data_type as col_type,
-           info.is_updatable as updatable,
-           info.character_maximum_length as max_len,
-           info.numeric_precision as precision,
-           info.column_default as default_value,
-           array_to_string(enum_info.vals, ',') as enum
-       from (
-         select table_schema, table_name, column_name, ordinal_position,
-                is_nullable, data_type, is_updatable,
-                character_maximum_length, numeric_precision,
-                column_default, udt_name
-           from information_schema.columns
-          where table_schema = ? and table_name = ?
-       ) as info
-       left outer join (
-         select n.nspname as s,
-                t.typname as n,
-                array_agg(e.enumlabel ORDER BY e.enumsortorder) as vals
-         from pg_type t
-            join pg_enum e on t.oid = e.enumtypid
-            join pg_catalog.pg_namespace n ON n.oid = t.typnamespace
-         group by s, n
-       ) as enum_info
-       on (info.udt_name = enum_info.n)
-    order by position |] (qtSchema table) (qtName table)
+      select info.table_schema as schema, info.table_name as table_name,
+             info.column_name as name, info.ordinal_position as position,
+             info.is_nullable as nullable, info.data_type as col_type,
+             info.is_updatable as updatable,
+             info.character_maximum_length as max_len,
+             info.numeric_precision as precision,
+             info.column_default as default_value,
+             array_to_string(enum_info.vals, ',') as enum
+         from (
+           select table_schema, table_name, column_name, ordinal_position,
+                  is_nullable, data_type, is_updatable,
+                  character_maximum_length, numeric_precision,
+                  column_default, udt_name
+             from information_schema.columns
+            where table_schema = ? and table_name = ?
+         ) as info
+         left outer join (
+           select n.nspname as s,
+                  t.typname as n,
+                  array_agg(e.enumlabel ORDER BY e.enumsortorder) as vals
+           from pg_type t
+              join pg_enum e on t.oid = e.enumtypid
+              join pg_catalog.pg_namespace n ON n.oid = t.typnamespace
+           group by s, n
+         ) as enum_info
+         on (info.udt_name = enum_info.n)
+      order by position |]
+    (qtSchema table) (qtName table)
 
   fks <- foreignKeys table
-  return $ map ((addFK fks) . column) cols
+  return $ map (addFK fks . columnFromRow) cols
 
   where
     addFK fks col = col { colFK = Map.lookup (cs . colName $ col) fks }
 
 
-primaryKeyColumns :: QualifiedTable -> H.Tx H.Postgres s [Text]
+primaryKeyColumns :: QualifiedTable -> H.Tx P.Postgres s [Text]
 primaryKeyColumns table = do
-  r :: [Identity Text] <- H.listEx $ [H.stmt|
+  r <- H.listEx $ [H.stmt|
     select kc.column_name
       from
         information_schema.table_constraints tc,
@@ -135,13 +134,13 @@ data Column = Column {
 , colFK :: Maybe ForeignKey
 } deriving (Show)
 
-table :: (Text, Text, Text) -> Table
-table (s, n, i) = Table s n (toBool i)
+tableFromRow :: (Text, Text, Text) -> Table
+tableFromRow (s, n, i) = Table s n (toBool i)
 
-column :: (Text, Text, Text, Int, Text, Text, Text,
+columnFromRow :: (Text, Text, Text, Int, Text, Text, Text,
            Maybe Int, Maybe Int, Maybe Text, Text)
        -> Column
-column (s, t, n, pos, nul, typ, u, l, p, d, e) =
+columnFromRow (s, t, n, pos, nul, typ, u, l, p, d, e) =
   Column s t n pos (toBool nul) typ (toBool u) l p d (split (==',') e) Nothing