Use makeAff instead of importing PS in FFI code

bower.json

@@ -3,7 +3,7 @@
   "license": "BSD-3-Clause",
   "dependencies": {
     "purescript-prelude": "^3.0.0",
-    "purescript-transformers": "^3.1.0",
+    "purescript-transformers": "^3.2.0",
     "purescript-lists": "^4.0.1",
     "purescript-foreign": "^4.0.0",
     "purescript-aff": "^3.0.0",

src/Database/PostgreSQL.js

@@ -1,52 +1,48 @@
 'use strict';
 
-var Control_Monad_Aff = require('../Control.Monad.Aff');
 var pg = require('pg');
 
-exports.newPool = function(config) {
-    return function(onSuccess, onError) {
-        onSuccess(new pg.Pool(config));
-        return Control_Monad_Aff.nonCanceler;
+exports.ffiNewPool = function(config) {
+    return function() {
+        return new pg.Pool(config);
     };
 };
 
-exports.withConnection = function(pool) {
-    return function(body) {
-        return function(onSuccess, onError) {
-            pool.connect(function(err, client, done) {
-                if (err !== null) {
-                    onError(err);
-                    return;
-                }
-                body(client)(function(r) {
-                    done();
-                    onSuccess(r);
-                }, function(e) {
-                    done(e);
-                    onError(e);
-                });
-            });
-            return Control_Monad_Aff.nonCanceler;
-        };
-    };
-};
-
-exports._query = function(client) {
-    return function(sql) {
-        return function(values) {
-            return function(onSuccess, onError) {
-                client.query({
-                    text: sql,
-                    values: values,
-                    rowMode: 'array',
-                }, function(err, result) {
+exports.ffiConnect = function(pool) {
+    return function(onError) {
+        return function(onSuccess) {
+            return function() {
+                pool.connect(function(err, client, done) {
                     if (err !== null) {
-                        onError(err);
+                        onError(err)();
                         return;
                     }
-                    onSuccess(result.rows);
+                    onSuccess({connection: client, done: done})();
                 });
-                return Control_Monad_Aff.nonCanceler;
+            };
+        };
+    };
+};
+
+exports.ffiUnsafeQuery = function(client) {
+    return function(sql) {
+        return function(values) {
+            return function(onError) {
+                return function(onSuccess) {
+                    return function() {
+                        client.query({
+                            text: sql,
+                            values: values,
+                            rowMode: 'array',
+                        }, function(err, result) {
+                            if (err !== null) {
+                                onError(err)();
+                                return;
+                            }
+                            onSuccess(result.rows)();
+                        });
+                    };
+                };
             };
         };
     };

src/Database/PostgreSQL.purs

@@ -12,12 +12,14 @@ module Database.PostgreSQL
 , execute
 , query
 , scalar
+, unsafeQuery
 ) where
 
-import Control.Monad.Aff (Aff)
-import Control.Monad.Eff (kind Effect)
-import Control.Monad.Eff.Exception (error)
-import Control.Monad.Error.Class (catchError, throwError)
+import Control.Monad.Aff (Aff, makeAff)
+import Control.Monad.Eff (kind Effect, Eff)
+import Control.Monad.Eff.Class (liftEff)
+import Control.Monad.Eff.Exception (Error, error)
+import Control.Monad.Error.Class (catchError, throwError, withResource)
 import Data.Array (head)
 import Data.Either (Either(..))
 import Data.Foreign (Foreign)
@@ -55,18 +57,36 @@ newtype Query i o = Query String
 derive instance newtypeQuery :: Newtype (Query i o) _
 
 -- | Create a new connection pool.
-foreign import newPool
+newPool :: ∀ eff. PoolConfiguration -> Aff (postgreSQL :: POSTGRESQL | eff) Pool
+newPool = liftEff <<< ffiNewPool
+
+foreign import ffiNewPool
     :: ∀ eff
      . PoolConfiguration
-    -> Aff (postgreSQL :: POSTGRESQL | eff) Pool
+    -> Eff (postgreSQL :: POSTGRESQL | eff) Pool
 
 -- | Run an action with a connection. The connection is released to the pool
 -- | when the action returns.
-foreign import withConnection
+withConnection
     :: ∀ eff a
      . Pool
     -> (Connection -> Aff (postgreSQL :: POSTGRESQL | eff) a)
     -> Aff (postgreSQL :: POSTGRESQL | eff) a
+withConnection p k =
+  withResource (makeAff $ ffiConnect p)
+               (liftEff <<< _.done)
+               (k <<< _.connection)
+
+foreign import ffiConnect
+    :: ∀ eff
+     . Pool
+    -> (Error -> Eff (postgreSQL :: POSTGRESQL | eff) Unit)
+    -> (    { connection :: Connection
+            , done :: Eff (postgreSQL :: POSTGRESQL | eff) Unit
+            }
+         -> Eff (postgreSQL :: POSTGRESQL | eff) Unit
+       )
+    -> Eff (postgreSQL :: POSTGRESQL | eff) Unit
 
 -- | Run an action within a transaction. The transaction is committed if the
 -- | action returns, and rolled back when the action throws. If you want to
@@ -92,7 +112,7 @@ execute
     -> i
     -> Aff (postgreSQL :: POSTGRESQL | eff) Unit
 execute conn (Query sql) values =
-    void $ _query conn sql (toSQLRow values)
+    void $ unsafeQuery conn sql (toSQLRow values)
 
 -- | Execute a PostgreSQL query and return its results.
 query
@@ -104,11 +124,13 @@ query
     -> i
     -> Aff (postgreSQL :: POSTGRESQL | eff) (Array o)
 query conn (Query sql) values =
-    _query conn sql (toSQLRow values)
+    unsafeQuery conn sql (toSQLRow values)
     >>= traverse (fromSQLRow >>> case _ of
           Right row -> pure row
           Left  msg -> throwError (error msg))
 
+-- | Execute a PostgreSQL query and return the first field of the first row in
+-- | the result.
 scalar
     :: ∀ i o eff
      . ToSQLRow i
@@ -121,12 +143,22 @@ scalar conn sql values =
     query conn sql values
     <#> map (case _ of Row1 a -> a) <<< head
 
-foreign import _query
+unsafeQuery
+  :: ∀ eff
+   . Connection
+  -> String
+  -> Array Foreign
+  -> Aff (postgreSQL :: POSTGRESQL | eff) (Array (Array Foreign))
+unsafeQuery c s a = makeAff $ ffiUnsafeQuery c s a
+
+foreign import ffiUnsafeQuery
     :: ∀ eff
      . Connection
     -> String
     -> Array Foreign
-    -> Aff (postgreSQL :: POSTGRESQL | eff) (Array (Array Foreign))
+    -> (Error -> Eff (postgreSQL :: POSTGRESQL | eff) Unit)
+    -> (Array (Array Foreign) -> Eff (postgreSQL :: POSTGRESQL | eff) Unit)
+    -> Eff (postgreSQL :: POSTGRESQL | eff) Unit
 
 fromRight :: ∀ a b. Either a b -> Maybe b
 fromRight (Left _) = Nothing