Add a module for generated lenses for Ganeti.Objects

The module also adds type classes for lenses for common fields (serial,
mTime, uuid and tags).

Splitting the lenses into a separate module avoids problems with unused
functions.
Signed-off-by: Petr Pudlak <pudlak@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Makefile.am

@@ -129,6 +129,7 @@ HS_DIRS = \
 	src/Ganeti/Locking \
 	src/Ganeti/Logging \
 	src/Ganeti/Monitoring \
+	src/Ganeti/Objects \
 	src/Ganeti/Query \
 	src/Ganeti/Storage \
 	src/Ganeti/Storage/Diskstats \
@@ -773,6 +774,7 @@ HS_LIB_SRCS = \
 	src/Ganeti/Metad.hs \
 	src/Ganeti/Network.hs \
 	src/Ganeti/Objects.hs \
+	src/Ganeti/Objects/Lens.hs \
 	src/Ganeti/OpCodes.hs \
 	src/Ganeti/OpParams.hs \
 	src/Ganeti/Path.hs \

src/Ganeti/Objects/Lens.hs

+{-# LANGUAGE TemplateHaskell #-}
+
+{-| Lenses for Ganeti config objects
+
+-}
+
+{-
+
+Copyright (C) 2014 Google Inc.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA.
+
+-}
+
+module Ganeti.Objects.Lens where
+
+import qualified Data.Set as Set
+import System.Time (ClockTime(..))
+
+import Ganeti.Lens (makeCustomLenses, Lens')
+import Ganeti.Objects
+
+-- | Class of objects that have timestamps.
+class TimeStampObject a => TimeStampObjectL a where
+  mTimeL :: Lens' a ClockTime
+
+-- | Class of objects that have an UUID.
+class UuidObject a => UuidObjectL a where
+  uuidL :: Lens' a String
+
+-- | Class of object that have a serial number.
+class SerialNoObject a => SerialNoObjectL a where
+  serialL :: Lens' a Int
+
+-- | Class of objects that have tags.
+class TagsObject a => TagsObjectL a where
+  tagsL :: Lens' a (Set.Set String)
+
+$(makeCustomLenses ''Network)
+
+instance SerialNoObjectL Network where
+  serialL = networkSerialL
+
+instance TagsObjectL Network where
+  tagsL = networkTagsL
+
+instance UuidObjectL Network where
+  uuidL = networkUuidL
+
+instance TimeStampObjectL Network where
+  mTimeL = networkMtimeL
+
+$(makeCustomLenses ''PartialNic)
+
+$(makeCustomLenses ''Disk)
+
+$(makeCustomLenses ''Instance)
+
+instance TimeStampObjectL Instance where
+  mTimeL = instMtimeL
+
+instance UuidObjectL Instance where
+  uuidL = instUuidL
+
+instance SerialNoObjectL Instance where
+  serialL = instSerialL
+
+instance TagsObjectL Instance where
+  tagsL = instTagsL
+
+$(makeCustomLenses ''MinMaxISpecs)
+
+$(makeCustomLenses ''PartialIPolicy)
+
+$(makeCustomLenses ''FilledIPolicy)
+
+$(makeCustomLenses ''Node)
+
+instance TimeStampObjectL Node where
+  mTimeL = nodeMtimeL
+
+instance UuidObjectL Node where
+  uuidL = nodeUuidL
+
+instance SerialNoObjectL Node where
+  serialL = nodeSerialL
+
+instance TagsObjectL Node where
+  tagsL = nodeTagsL
+
+$(makeCustomLenses ''NodeGroup)
+
+instance TimeStampObjectL NodeGroup where
+  mTimeL = groupMtimeL
+
+instance UuidObjectL NodeGroup where
+  uuidL = groupUuidL
+
+instance SerialNoObjectL NodeGroup where
+  serialL = groupSerialL
+
+instance TagsObjectL NodeGroup where
+  tagsL = groupTagsL
+
+$(makeCustomLenses ''Cluster)
+
+instance TimeStampObjectL Cluster where
+  mTimeL = clusterMtimeL
+
+instance UuidObjectL Cluster where
+  uuidL = clusterUuidL
+
+instance SerialNoObjectL Cluster where
+  serialL = clusterSerialL
+
+instance TagsObjectL Cluster where
+  tagsL = clusterTagsL
+
+$(makeCustomLenses ''ConfigData)
+
+instance SerialNoObjectL ConfigData where
+  serialL = configSerialL
+
+instance TimeStampObjectL ConfigData where
+  mTimeL = configMtimeL