chore: prepare v1.3.0

README.md

@@ -255,59 +255,59 @@ the api of [`node-postgres`]:
   - release clients with [`Pool.release`] or [`Pool.destroy`]
   - release with [`Pool.end`]
 
-[`Pool`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Effect.Aff.Postgres.Pool#t:Pool
-[`Config`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Effect.Aff.Postgres.Pool#t:Config
-[`Pool.make`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Effect.Aff.Postgres.Pool#v:make
-[`Pool.end`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Effect.Aff.Postgres.Pool#v:end
-[`Pool.connect`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Effect.Aff.Postgres.Pool#v:connect
-[`Pool.destroy`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Effect.Aff.Postgres.Pool#v:destroy
-[`Pool.release`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Effect.Aff.Postgres.Pool#v:release
+[`Pool`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Effect.Aff.Postgres.Pool#t:Pool
+[`Config`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Effect.Aff.Postgres.Pool#t:Config
+[`Pool.make`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Effect.Aff.Postgres.Pool#v:make
+[`Pool.end`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Effect.Aff.Postgres.Pool#v:end
+[`Pool.connect`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Effect.Aff.Postgres.Pool#v:connect
+[`Pool.destroy`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Effect.Aff.Postgres.Pool#v:destroy
+[`Pool.release`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Effect.Aff.Postgres.Pool#v:release
 
-[`Client`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Effect.Aff.Postgres.Client#t:Client
-[`Client.end`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Effect.Aff.Postgres.Client#v:end
-[`Client.make`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Effect.Aff.Postgres.Client#v:make
-[`Client.connected`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Effect.Aff.Postgres.Client#v:connected
-[`Client.query`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Effect.Aff.Postgres.Client#v:query
-[`Client.queryRaw`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Effect.Aff.Postgres.Client#v:queryRaw
-[`Client.exec`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Effect.Aff.Postgres.Client#v:exec
+[`Client`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Effect.Aff.Postgres.Client#t:Client
+[`Client.end`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Effect.Aff.Postgres.Client#v:end
+[`Client.make`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Effect.Aff.Postgres.Client#v:make
+[`Client.connected`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Effect.Aff.Postgres.Client#v:connected
+[`Client.query`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Effect.Aff.Postgres.Client#v:query
+[`Client.queryRaw`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Effect.Aff.Postgres.Client#v:queryRaw
+[`Client.exec`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Effect.Aff.Postgres.Client#v:exec
 
-[`Range`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Range#t:Range
-[`Range.gt`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Range#v:gt
-[`Range.gte`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Range#v:gte
-[`Range.lt`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Range#v:lt
-[`Range.lte`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Range#v:lte
+[`Range`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Range#t:Range
+[`Range.gt`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Range#v:gt
+[`Range.gte`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Range#v:gte
+[`Range.lt`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Range#v:lt
+[`Range.lte`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Range#v:lte
 
-[`Raw`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Raw#t:Raw
-[`Null`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Raw#t:Null
+[`Raw`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Raw#t:Raw
+[`Null`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Raw#t:Null
 
-[`Serialize`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres#t:Serialize
-[`Deserialize`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres#t:Deserialize
-[`Rep`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres#t:Rep
-[`modifyPgTypes`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres#v:modifyPgTypes
+[`Serialize`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres#t:Serialize
+[`Deserialize`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres#t:Deserialize
+[`Rep`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres#t:Rep
+[`modifyPgTypes`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres#v:modifyPgTypes
 
-[`Result`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Result#t:Result
-[`FromRow`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Result#t:FromRow
-[`FromRows`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Result#t:FromRows
+[`Result`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Result#t:Result
+[`FromRow`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Result#t:FromRow
+[`FromRows`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Result#t:FromRows
 
-[`Query`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Query#t:Query
-[`AsQuery`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Query#t:AsQuery
+[`Query`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Query#t:Query
+[`AsQuery`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Query#t:AsQuery
 
-[`Query.Builder`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Query.Builder#t:Builder
-[`Query.Builder.param`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Query.Builder#v:param
-[`Query.Builder.build`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Data.Postgres.Query.Builder#v:build
+[`Query.Builder`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Query.Builder#t:Builder
+[`Query.Builder.param`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Query.Builder#v:param
+[`Query.Builder.build`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Data.Postgres.Query.Builder#v:build
 
-[`MonadCursor`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Control.Monad.Postgres#t:MonadCursor
-[`MonadSession`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Control.Monad.Postgres#t:MonadSession
-[`CursorT`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Control.Monad.Postgres#t:CursorT
-[`SessionT`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Control.Monad.Postgres#t:SessionT
-[`PostgresT`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Control.Monad.Postgres#t:PostgresT
-[`cursor`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Control.Monad.Postgres#v:cursor
-[`session`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Control.Monad.Postgres#v:session
-[`transaction`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Control.Monad.Postgres#v:transaction
-[`runPostgres`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Control.Monad.Postgres#v:runPostgres
-[`query`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Control.Monad.Postgres#v:query
-[`exec`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Control.Monad.Postgres#v:exec
-[`exec_`]: https://pursuit.purescript.org///////packages/purescript-postgresql/1.1.1/docs/Control.Monad.Postgres#v:exec_
+[`MonadCursor`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Control.Monad.Postgres#t:MonadCursor
+[`MonadSession`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Control.Monad.Postgres#t:MonadSession
+[`CursorT`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Control.Monad.Postgres#t:CursorT
+[`SessionT`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Control.Monad.Postgres#t:SessionT
+[`PostgresT`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Control.Monad.Postgres#t:PostgresT
+[`cursor`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Control.Monad.Postgres#v:cursor
+[`session`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Control.Monad.Postgres#v:session
+[`transaction`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Control.Monad.Postgres#v:transaction
+[`runPostgres`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Control.Monad.Postgres#v:runPostgres
+[`query`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Control.Monad.Postgres#v:query
+[`exec`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Control.Monad.Postgres#v:exec
+[`exec_`]: https://pursuit.purescript.org//////////////////packages/purescript-postgresql/1.3.0/docs/Control.Monad.Postgres#v:exec_
 
 [`node-postgres`]: https://node-postgres.com/
 [`pg-types`]: https://github.com/brianc/node-pg-types/

spago.lock

@@ -32,9 +32,11 @@ workspace:
         - record: ">=4.0.0 <5.0.0"
         - simple-json: ">=9.0.0 <10.0.0"
         - strings: ">=6.0.1 <7.0.0"
+        - tailrec: ">=6.1.0 <7.0.0"
         - transformers: ">=6.0.0 <7.0.0"
         - tuples: ">=7.0.0 <8.0.0"
         - typelevel-prelude: ">=7.0.0 <8.0.0"
+        - unlift: ">=1.0.1 <2.0.0"
         - unsafe-coerce: ">=6.0.0 <7.0.0"
       test_dependencies:
         - filterable
@@ -73,6 +75,7 @@ workspace:
         - fork
         - formatters
         - free
+        - freet
         - functions
         - functors
         - gen
@@ -86,6 +89,7 @@ workspace:
         - lists
         - maybe
         - mmorph
+        - monad-control
         - newtype
         - node-buffer
         - node-child-process
@@ -126,6 +130,7 @@ workspace:
         - typelevel-prelude
         - unfoldable
         - unicode
+        - unlift
         - unsafe-coerce
         - variant
   package_set:
@@ -923,6 +928,21 @@ packages:
       - transformers
       - tuples
       - unsafe-coerce
+  freet:
+    type: registry
+    version: 7.0.0
+    integrity: sha256-zkL6wU4ZPq8xz1kGFxoliWqyhBksepMJTyA68VEBaJo=
+    dependencies:
+      - aff
+      - bifunctors
+      - effect
+      - either
+      - exists
+      - free
+      - prelude
+      - tailrec
+      - transformers
+      - tuples
   functions:
     type: registry
     version: 6.0.0
@@ -1059,6 +1079,15 @@ packages:
       - free
       - functors
       - transformers
+  monad-control:
+    type: registry
+    version: 5.0.0
+    integrity: sha256-bgfDW30wbIm70NR1Tvvh9P+VFQMDh1wK2sSJXCj/dZc=
+    dependencies:
+      - aff
+      - freet
+      - identity
+      - lists
   newtype:
     type: registry
     version: 5.0.0
@@ -1566,6 +1595,23 @@ packages:
       - foldable-traversable
       - maybe
       - strings
+  unlift:
+    type: registry
+    version: 1.0.1
+    integrity: sha256-nbBCVV0fZz/3UHKoW11dcTwBYmQOIgK31ht2BN47RPw=
+    dependencies:
+      - aff
+      - effect
+      - either
+      - freet
+      - identity
+      - lists
+      - maybe
+      - monad-control
+      - prelude
+      - st
+      - transformers
+      - tuples
   unsafe-coerce:
     type: registry
     version: 6.0.0

spago.yaml

@@ -1,7 +1,7 @@
 package:
   name: postgresql
   publish:
-    version: '1.1.1'
+    version: '1.3.0'
     license: 'GPL-3.0-or-later'
     location:
       githubOwner: 'cakekindel'
@@ -42,9 +42,11 @@ package:
     - record: ">=4.0.0 <5.0.0"
     - simple-json: ">=9.0.0 <10.0.0"
     - strings: ">=6.0.1 <7.0.0"
+    - tailrec: ">=6.1.0 <7.0.0"
     - transformers: ">=6.0.0 <7.0.0"
     - tuples: ">=7.0.0 <8.0.0"
     - typelevel-prelude: ">=7.0.0 <8.0.0"
+    - unlift: ">=1.0.1 <2.0.0"
     - unsafe-coerce: ">=6.0.0 <7.0.0"
   test:
     main: Test.Main

src/Control.Monad.Postgres.Base.purs

@@ -7,17 +7,24 @@ import Control.Alternative (class Plus)
 import Control.Monad.Error.Class (class MonadError, class MonadThrow, catchError, throwError)
 import Control.Monad.Fork.Class (class MonadBracket, class MonadFork, class MonadKill, bracket, kill, never, uninterruptible)
 import Control.Monad.Morph (class MFunctor, class MMonad)
+import Control.Monad.Postgres.Cursor (class MonadCursor, CursorT)
 import Control.Monad.Postgres.Session (class MonadSession, SessionT, exec, exec_, query)
 import Control.Monad.Reader (class MonadAsk, class MonadReader, ReaderT, ask, local, runReaderT)
+import Control.Monad.Rec.Class (class MonadRec)
 import Control.Monad.Trans.Class (class MonadTrans, lift)
 import Control.Parallel (class Parallel, parallel, sequential)
 import Data.Newtype (class Newtype, unwrap, wrap)
-import Effect.Aff (Fiber)
+import Data.Postgres (RepT)
+import Data.Postgres.Query (class AsQuery, asQuery)
+import Data.Postgres.Raw (Raw)
+import Data.Postgres.Result (class FromRow, fromRow)
+import Data.Tuple.Nested ((/\))
 import Effect.Aff.Class (class MonadAff, liftAff)
 import Effect.Aff.Postgres.Pool (Pool)
 import Effect.Aff.Postgres.Pool as Pool
+import Effect.Aff.Unlift (class MonadUnliftAff)
 import Effect.Class (class MonadEffect, liftEffect)
-import Effect.Exception (Error)
+import Effect.Unlift (class MonadUnliftEffect)
 import Prim.Row (class Union)
 
 -- | Monad handling pool resource acquisition & release
@@ -57,6 +64,9 @@ derive newtype instance (Bind m) => Bind (PostgresT m)
 derive newtype instance (Monad m) => Monad (PostgresT m)
 derive newtype instance (MonadEffect m) => MonadEffect (PostgresT m)
 derive newtype instance (MonadAff m) => MonadAff (PostgresT m)
+derive newtype instance (MonadUnliftEffect m) => MonadUnliftEffect (PostgresT m)
+derive newtype instance (MonadUnliftAff m) => MonadUnliftAff (PostgresT m)
+derive newtype instance MonadRec m => MonadRec (PostgresT m)
 derive newtype instance MonadTrans (PostgresT)
 derive newtype instance (MonadThrow e m) => MonadThrow e (PostgresT m)
 derive newtype instance (MonadError e m) => MonadError e (PostgresT m)
@@ -86,29 +96,48 @@ instance (MonadBracket e f m, MonadAff m) => MonadSession (PostgresT m) where
   exec = session <<< exec
   exec_ = session <<< exec_
 
--- | Lifts a session to `PostgresT`, releasing the client to the pool
--- | after execution.
-session :: forall e f m a. MonadBracket e f m => MonadAff m => MonadSession (SessionT m) => SessionT m a -> PostgresT m a
-session m = do
-  pool <- ask
-  let
-    acq = liftAff $ Pool.connect pool
-    rel _ c = liftEffect $ Pool.release pool c
-  lift $ bracket acq rel (runReaderT m)
-
--- | Lifts a session to `PostgresT`, running the session
--- | in a transaction.
+-- | Typeclass generalizing `PostgresT`. Allows for dependency-injecting different
+-- | implementations of the idea of a postgres connection.
 -- |
--- | If the session throws an error, the transaction will be
--- | rolled back and the error rethrown.
-transaction :: forall m a. MonadBracket Error Fiber m => MonadAff m => MonadSession (SessionT m) => SessionT m a -> PostgresT m a
-transaction m =
-  let
-    begin = void $ exec "begin;"
-    commit = m <* exec "commit;"
-    rollback e = exec "rollback;" *> throwError e
-  in
-    session $ begin *> catchError commit rollback
+-- | - `session` - Session monad (for `PostgresT` this is `SessionT`)
+-- | - `cursor` - Cursor session monad (for `PostgresT` this is `CursorT`)
+-- | - `ct` - Open type parameter for cursor type. Don't pin this to a concrete type.
+class (MonadSession session, MonadCursor cursor ct) <= MonadPostgres m session cursor ct | m -> ct cursor session where
+  -- | Run a session in `m`.
+  session :: session ~> m
+  -- | Run a session in `m`, wrapped in a transaction.
+  -- |
+  -- | If any errors are raised, the transaction is rolled back and
+  -- | the error rethrown.
+  transaction :: session ~> m
+  -- | `cursor`, but using a custom deserialize function for the data
+  -- | yielded by the cursor
+  cursorWith :: forall q. AsQuery q => (Array Raw -> RepT ct) -> String -> q -> cursor ~> m
+
+instance (MonadBracket e f m, MonadAff m, MonadSession (SessionT m), MonadCursor (CursorT t (SessionT m)) t) => MonadPostgres (PostgresT m) (SessionT m) (CursorT ct (SessionT m)) ct where
+  session m = do
+    pool <- ask
+    let
+      acq = liftAff $ Pool.connect pool
+      rel _ c = liftEffect $ Pool.release pool c
+    lift $ bracket acq rel (runReaderT m)
+  transaction m =
+    let
+      begin = void $ exec "begin;"
+      commit = m <* exec "commit;"
+      rollback e = exec "rollback;" *> throwError e
+    in
+      session $ begin *> catchError commit rollback
+  cursorWith f cur q m =
+    transaction do
+      q' <- liftEffect $ asQuery q
+      exec_ $ "declare " <> cur <> " cursor for (" <> (unwrap q').text <> ");"
+      runReaderT (unwrap m) (cur /\ f)
+
+-- | Create a server-side cursor for a query in a transaction,
+-- | and execute a `CursorT` with a view to the new cursor.
+cursor :: forall @cursort t session cursor q a. MonadPostgres t session cursor cursort => AsQuery q => FromRow cursort => String -> q -> cursor a -> t a
+cursor = cursorWith fromRow
 
 -- | Execute a `PostgresT` using an existing connection pool.
 -- |

src/Control.Monad.Postgres.Cursor.purs

@@ -6,23 +6,25 @@ import Control.Alt (class Alt)
 import Control.Alternative (class Plus)
 import Control.Monad.Error.Class (class MonadError, class MonadThrow)
 import Control.Monad.Fork.Class (class MonadBracket, class MonadFork, class MonadKill, bracket, kill, never, uninterruptible)
-import Control.Monad.Postgres.Base (PostgresT, transaction)
-import Control.Monad.Postgres.Session (class MonadSession, SessionT, exec, exec_, query)
-import Control.Monad.Reader (class MonadAsk, class MonadReader, ReaderT, ask, local, runReaderT)
+import Control.Monad.Postgres.Session (class MonadSession, exec, exec_, query)
+import Control.Monad.Reader (class MonadAsk, class MonadReader, ReaderT, ask, local)
+import Control.Monad.Rec.Class (class MonadRec)
 import Control.Monad.Trans.Class (class MonadTrans, lift)
 import Control.Parallel (class Parallel, parallel, sequential)
 import Data.Array as Array
 import Data.Maybe (Maybe)
 import Data.Newtype (class Newtype, unwrap, wrap)
-import Data.Postgres.Query (class AsQuery, asQuery)
-import Data.Postgres.Result (class FromRow)
-import Effect.Aff (Fiber)
+import Data.Postgres (RepT, smash)
+import Data.Postgres.Raw (Raw)
+import Data.Traversable (traverse)
+import Data.Tuple.Nested (type (/\), (/\))
 import Effect.Aff.Class (class MonadAff)
+import Effect.Aff.Unlift (class MonadUnliftAff)
 import Effect.Class (class MonadEffect, liftEffect)
-import Effect.Exception (Error)
+import Effect.Unlift (class MonadUnliftEffect)
 
 newtype CursorT :: forall k. Type -> (k -> Type) -> k -> Type
-newtype CursorT t m a = CursorT (ReaderT String m a)
+newtype CursorT t m a = CursorT (ReaderT (String /\ (Array Raw -> RepT t)) m a)
 
 derive instance Newtype (CursorT t m a) _
 derive newtype instance (Functor m) => Functor (CursorT t m)
@@ -34,6 +36,9 @@ derive newtype instance (Bind m) => Bind (CursorT t m)
 derive newtype instance (Monad m) => Monad (CursorT t m)
 derive newtype instance (MonadEffect m) => MonadEffect (CursorT t m)
 derive newtype instance (MonadAff m) => MonadAff (CursorT t m)
+derive newtype instance MonadRec m => MonadRec (CursorT t m)
+derive newtype instance (MonadUnliftEffect m) => MonadUnliftEffect (CursorT t m)
+derive newtype instance (MonadUnliftAff m) => MonadUnliftAff (CursorT t m)
 derive newtype instance MonadTrans (CursorT t)
 derive newtype instance (MonadThrow e m) => MonadThrow e (CursorT t m)
 derive newtype instance (MonadError e m) => MonadError e (CursorT t m)
@@ -46,10 +51,10 @@ instance (Monad m, MonadBracket e f (ReaderT String m), MonadBracket e f m) => M
   uninterruptible a = wrap $ uninterruptible $ unwrap a
   never = lift $ never
 
-instance Monad m => MonadAsk String (CursorT t m) where
+instance Monad m => MonadAsk (String /\ (Array Raw -> RepT t)) (CursorT t m) where
   ask = wrap ask
 
-instance Monad m => MonadReader String (CursorT t m) where
+instance Monad m => MonadReader (String /\ (Array Raw -> RepT t)) (CursorT t m) where
   local f m = wrap $ local f $ unwrap m
 
 instance (Apply m, Apply p, Parallel p m) => Parallel (CursorT t p) (CursorT t m) where
@@ -78,19 +83,21 @@ instance (Apply m, Apply p, Parallel p m) => Parallel (CursorT t p) (CursorT t m
 -- |     e <- fetchAll -- 15..100
 -- |     pure unit
 -- | ```
-class (MonadSession m, FromRow t) <= MonadCursor m t where
+class (MonadSession m) <= MonadCursor m t where
   -- | Fetch a specified number of rows from the cursor
   fetch :: Int -> m (Array t)
   -- | Fetch all remaining rows from the cursor
   fetchAll :: m (Array t)
 
-instance (FromRow t, MonadSession m) => MonadCursor (CursorT t m) t where
+instance (MonadSession m) => MonadCursor (CursorT t m) t where
   fetch n = do
-    cur <- ask
-    query $ "fetch forward " <> show n <> " from " <> cur
+    cur /\ f <- ask
+    raw :: Array (Array Raw) <- query $ "fetch forward " <> show n <> " from " <> cur
+    liftEffect $ smash $ traverse f raw
   fetchAll = do
-    cur <- ask
-    query $ "fetch all from " <> cur
+    cur /\ f <- ask
+    raw :: Array (Array Raw) <- query $ "fetch all from " <> cur
+    liftEffect $ smash $ traverse f raw
 
 instance (MonadSession m) => MonadSession (CursorT t m) where
   query = lift <<< query
@@ -100,12 +107,3 @@ instance (MonadSession m) => MonadSession (CursorT t m) where
 -- | Fetch the next row from the cursor
 fetchOne :: forall m t. MonadCursor m t => m (Maybe t)
 fetchOne = Array.head <$> fetch 1
-
--- | Create a server-side cursor for a query in a transaction,
--- | and execute a `CursorT` with a view to the new cursor.
-cursor :: forall m @t a q. AsQuery q => MonadAff m => MonadBracket Error Fiber m => MonadSession (SessionT m) => String -> q -> CursorT t (SessionT m) a -> PostgresT m a
-cursor cur q m =
-  transaction do
-    q' <- liftEffect $ asQuery q
-    exec_ $ "declare " <> cur <> " cursor for (" <> (unwrap q').text <> ");"
-    runReaderT (unwrap m) cur

src/Data.Postgres.Custom.Enum.purs

@@ -5,6 +5,7 @@ import Prelude
 import Control.Alt ((<|>))
 import Control.Monad.Error.Class (liftMaybe)
 import Data.Array.NonEmpty.Internal (NonEmptyArray)
+import Data.Bifunctor (lmap)
 import Data.Foldable (intercalate)
 import Data.Generic.Rep (class Generic)
 import Data.Generic.Rep as G
@@ -17,7 +18,7 @@ import Data.Postgres.Raw (Raw)
 import Data.Symbol (class IsSymbol)
 import Data.Traversable (find)
 import Data.Tuple (fst, snd)
-import Data.Tuple.Nested (type (/\))
+import Data.Tuple.Nested (type (/\), (/\))
 import Foreign (ForeignError(..))
 import Type.Prelude (Proxy(..), reflectSymbol)
 
@@ -45,19 +46,19 @@ defaultSerializeEnum :: forall @a ty. CustomEnum a ty => a -> RepT Raw
 defaultSerializeEnum = serialize <<< printEnum
 
 class GenericCustomEnum a where
-  genericEnumVariants' :: NonEmptyArray a
+  genericEnumVariants' :: NonEmptyArray (a /\ String)
   genericParseEnum' :: String -> Maybe a
   genericPrintEnum' :: a -> String
 
 instance IsSymbol n => GenericCustomEnum (G.Constructor n G.NoArguments) where
-  genericEnumVariants' = pure (G.Constructor @n G.NoArguments)
+  genericEnumVariants' = pure (G.Constructor @n G.NoArguments /\ reflectSymbol (Proxy @n))
   genericParseEnum' s
     | s == reflectSymbol (Proxy @n) = Just (G.Constructor @n G.NoArguments)
     | otherwise = Nothing
   genericPrintEnum' _ = reflectSymbol (Proxy @n)
 
 instance (GenericCustomEnum a, GenericCustomEnum b) => GenericCustomEnum (G.Sum a b) where
-  genericEnumVariants' = (G.Inl <$> genericEnumVariants' @a) <> (G.Inr <$> genericEnumVariants' @b)
+  genericEnumVariants' = (lmap G.Inl <$> genericEnumVariants' @a) <> (lmap G.Inr <$> genericEnumVariants' @b)
   genericParseEnum' s = (G.Inl <$> genericParseEnum' @a s) <|> (G.Inr <$> genericParseEnum' @b s)
   genericPrintEnum' (G.Inl a) = genericPrintEnum' a
   genericPrintEnum' (G.Inr a) = genericPrintEnum' a
@@ -65,8 +66,8 @@ instance (GenericCustomEnum a, GenericCustomEnum b) => GenericCustomEnum (G.Sum
 enumPrintExpr :: forall @a ty. CustomEnum a ty => a -> Maybe String
 enumPrintExpr = Just <<< (\s -> quoted s <> " :: " <> typeName @a) <<< printEnum
 
-genericEnumVariants :: forall a g. Generic a g => GenericCustomEnum g => NonEmptyArray a
-genericEnumVariants = G.to <$> genericEnumVariants'
+genericEnumVariants :: forall a g. Generic a g => GenericCustomEnum g => NonEmptyArray (a /\ String)
+genericEnumVariants = lmap G.to <$> genericEnumVariants'
 
 genericParseEnum :: forall a g. Generic a g => GenericCustomEnum g => String -> Maybe a
 genericParseEnum = map G.to <<< genericParseEnum'

src/Data.Postgres.Result.purs

@@ -8,7 +8,7 @@ import Data.Int as Int
 import Data.Maybe (Maybe)
 import Data.Nullable (Nullable)
 import Data.Nullable as Nullable
-import Data.Postgres (class Rep, RepT, deserialize)
+import Data.Postgres (class Deserialize, class Rep, RepT, deserialize)
 import Data.Postgres.Raw (Raw)
 import Data.Traversable (traverse)
 import Data.Tuple (Tuple)
@@ -79,7 +79,7 @@ class FromRow (a :: Type) where
   -- | Performs the conversion
   fromRow :: Array Raw -> RepT a
 
-instance (Rep a, FromRow b) => FromRow (a /\ b) where
+instance (Deserialize a, FromRow b) => FromRow (a /\ b) where
   minColumnCount _ = minColumnCount (Proxy @b) + 1
   fromRow r =
     let
@@ -97,7 +97,7 @@ else instance FromRow (Array Raw) where
 else instance FromRow Unit where
   minColumnCount _ = 0
   fromRow _ = pure unit
-else instance Rep a => FromRow a where
+else instance Deserialize a => FromRow a where
   minColumnCount _ = 1
   fromRow r =
     let

src/Data.Postgres.Unresult.purs

@@ -0,0 +1,27 @@
+module Data.Postgres.Unresult where
+
+import Prelude
+
+import Control.Monad.Error.Class (liftMaybe)
+import Control.Monad.State (StateT, runStateT, state)
+import Data.Array as Array
+import Data.Postgres (class Deserialize, RepT, deserialize, smash)
+import Data.Postgres.Raw (Raw)
+import Data.Tuple (fst)
+import Data.Tuple.Nested ((/\))
+import Effect.Class (liftEffect)
+import Foreign (ForeignError(..))
+
+-- | Monad used to incrementally deserialize columns from a row
+type Unresult a = StateT { ix :: Int, row :: Array Raw } RepT a
+
+-- | Run an `UnresultT`
+unresult :: forall a. Unresult a -> Array Raw -> RepT a
+unresult m row = fst <$> runStateT m { ix: 0, row }
+
+-- | Take the next column from the row, unmarshalling into `a`
+take :: forall a. Deserialize a => Unresult a
+take = do
+  raw <- state (\r -> Array.index r.row r.ix /\ r { ix = r.ix + 1 })
+  raw' <- liftMaybe (pure $ ForeignError $ "Ran out of columns!") raw
+  liftEffect $ smash $ deserialize raw'

src/Data.Postgres.purs

@@ -41,7 +41,7 @@ derive newtype instance ReadForeign a => ReadForeign (JSON a)
 foreign import modifyPgTypes :: Effect Unit
 
 -- | The serialization & deserialization monad.
-type RepT a = ExceptT (NonEmptyList ForeignError) Effect a
+type RepT = ExceptT (NonEmptyList ForeignError) Effect
 
 -- | Flatten to an Effect, `show`ing errors
 smash :: forall a. RepT a -> Effect a

test/Test.Data.Postgres.Generic.purs

@@ -10,7 +10,7 @@ import Data.Generic.Rep (class Generic)
 import Data.Maybe (Maybe(..))
 import Data.Newtype (unwrap)
 import Data.Postgres (class Deserialize, class Serialize, deserialize, serialize, smash)
-import Data.Postgres.Custom.Enum (class CustomEnum, create, enumDeserialize, enumPrintExpr, enumSerialize, genericEnumVariants, genericParseEnum, genericPrintEnum, parseEnum, printEnum)
+import Data.Postgres.Custom.Enum (class CustomEnum, create, defaultDeserializeEnum, defaultSerializeEnum, enumPrintExpr, genericEnumVariants, genericParseEnum, genericPrintEnum, parseEnum, printEnum)
 import Data.Show.Generic (genericShow)
 import Effect.Class (liftEffect)
 import Test.Spec (Spec, describe, it)
@@ -25,10 +25,10 @@ instance Show Enum1 where
   show = genericShow
 
 instance Serialize Enum1 where
-  serialize a = enumSerialize a
+  serialize a = defaultSerializeEnum a
 
 instance Deserialize Enum1 where
-  deserialize a = enumDeserialize a
+  deserialize a = defaultDeserializeEnum a
 
 instance CustomEnum Enum1 "enum_1" where
   printEnum = genericPrintEnum
@@ -43,10 +43,10 @@ instance Show Enum2 where
   show = genericShow
 
 instance Serialize Enum2 where
-  serialize a = enumSerialize a
+  serialize a = defaultSerializeEnum a
 
 instance Deserialize Enum2 where
-  deserialize a = enumDeserialize a
+  deserialize a = defaultDeserializeEnum a
 
 instance CustomEnum Enum2 "enum_2" where
   printEnum a = genericPrintEnum a
@@ -61,10 +61,10 @@ instance Show Enum5 where
   show = genericShow
 
 instance Serialize Enum5 where
-  serialize a = enumSerialize a
+  serialize a = defaultSerializeEnum a
 
 instance Deserialize Enum5 where
-  deserialize a = enumDeserialize a
+  deserialize a = defaultDeserializeEnum a
 
 instance CustomEnum Enum5 "enum_5" where
   printEnum a = genericPrintEnum a