Packages needed for Yesod + Postgresql development

pkgs/development/libraries/haskell/persistent-postgresql/default.nix

@@ -0,0 +1,19 @@
+{ cabal, aeson, conduit, monadControl, persistent, postgresqlLibpq
+, postgresqlSimple, text, time, transformers
+}:
+
+cabal.mkDerivation (self: {
+  pname = "persistent-postgresql";
+  version = "0.9.1";
+  sha256 = "0kzw4lq4i6lj149aws4ca4z43jmwvcbjr5gf5lk0pwcmzp6chr32";
+  buildDepends = [
+    aeson conduit monadControl persistent postgresqlLibpq
+    postgresqlSimple text time transformers
+  ];
+  meta = {
+    homepage = "http://www.yesodweb.com/book/persistent";
+    description = "Backend for the persistent library using postgresql";
+    license = self.stdenv.lib.licenses.mit;
+    platforms = self.ghc.meta.platforms;
+  };
+})

pkgs/development/libraries/haskell/postgresql-libpq/default.nix

@@ -0,0 +1,14 @@
+{ cabal, postgresql }:
+
+cabal.mkDerivation (self: {
+  pname = "postgresql-libpq";
+  version = "0.8.2";
+  sha256 = "10i3yc5fxlmnrb8j9p2a9w7h49p3ain36qpshlb34chdk9xh3l7g";
+  extraLibraries = [ postgresql ];
+  meta = {
+    homepage = "http://github.com/lpsmith/postgresql-libpq";
+    description = "low-level binding to libpq";
+    license = self.stdenv.lib.licenses.bsd3;
+    platforms = self.ghc.meta.platforms;
+  };
+})

pkgs/development/libraries/haskell/postgresql-simple/default.nix

@@ -0,0 +1,18 @@
+{ cabal, attoparsec, blazeBuilder, blazeTextual, postgresqlLibpq
+, text, time, transformers, vector
+}:
+
+cabal.mkDerivation (self: {
+  pname = "postgresql-simple";
+  version = "0.1.4.3";
+  sha256 = "0q0mkkd22hji7ns25i86shy1504d0d4mc3fqljpfffm6m36855kc";
+  buildDepends = [
+    attoparsec blazeBuilder blazeTextual postgresqlLibpq text time
+    transformers vector
+  ];
+  meta = {
+    description = "Mid-Level PostgreSQL client library";
+    license = self.stdenv.lib.licenses.bsd3;
+    platforms = self.ghc.meta.platforms;
+  };
+})

pkgs/top-level/haskell-packages.nix

@@ -1129,6 +1129,8 @@ let result = let callPackage = x : y : modifyPrio (newScope result.final x y);
 
   persistent = callPackage ../development/libraries/haskell/persistent {};
 
+  persistentPostgresql = callPackage ../development/libraries/haskell/persistent-postgresql {};
+
   persistentSqlite = callPackage ../development/libraries/haskell/persistent-sqlite {};
 
   persistentTemplate = callPackage ../development/libraries/haskell/persistent-template {};
@@ -1141,6 +1143,12 @@ let result = let callPackage = x : y : modifyPrio (newScope result.final x y);
 
   poolConduit = callPackage ../development/libraries/haskell/pool-conduit {};
 
+  postgresqlLibpq = callPackage ../development/libraries/haskell/postgresql-libpq {
+    postgresql = pkgs.postgresql91;
+  };
+
+  postgresqlSimple = callPackage ../development/libraries/haskell/postgresql-simple {};
+
   ppm = callPackage ../development/libraries/haskell/ppm {};
 
   prettyShow = callPackage ../development/libraries/haskell/pretty-show {};