add higher-leveldb from hackage

pkgs/development/libraries/haskell/higher-leveldb/default.nix

@@ -0,0 +1,25 @@
+# This file was auto-generated by cabal2nix. Please do NOT edit manually!
+
+{ cabal, cereal, dataDefault, hspec, leveldbHaskell, liftedBase
+, monadControl, mtl, resourcet, transformers, transformersBase
+}:
+
+cabal.mkDerivation (self: {
+  pname = "higher-leveldb";
+  version = "0.2.0.0";
+  sha256 = "1al8l96ysmcjx3g93ryfr939jqhjqk8g5bvww5gj9mx6pdkqrcm3";
+  buildDepends = [
+    cereal dataDefault leveldbHaskell liftedBase monadControl mtl
+    resourcet transformers transformersBase
+  ];
+  testDepends = [
+    cereal hspec leveldbHaskell liftedBase monadControl mtl resourcet
+    transformers transformersBase
+  ];
+  meta = {
+    homepage = "https://github.com/jeremyjh/higher-leveldb";
+    description = "A rich monadic API for working with leveldb databases";
+    license = self.stdenv.lib.licenses.bsd3;
+    platforms = self.ghc.meta.platforms;
+  };
+})

pkgs/top-level/haskell-packages.nix

@@ -1105,6 +1105,8 @@ self : let callPackage = x : y : modifyPrio (newScope self x y); in
 
   hgal = callPackage ../development/libraries/haskell/hgal {};
 
+  higherLeveldb = callPackage ../development/libraries/haskell/higher-leveldb {};
+
   hourglass = callPackage ../development/libraries/haskell/hourglass {};
 
   hplayground = callPackage ../development/libraries/haskell/hplayground {};