GADT properties seem to work (untested)

* Property has been converted to a GADT, and will be Property NoInfo
  or Property HasInfo.
  This was done to make sure that ensureProperty is only used on
  properties that do not have Info.
  Transition guide:
  - Change all "Property" to "Property NoInfo" or "Property WithInfo"
    (The compiler can tell you if you got it wrong!)
  - To construct a RevertableProperty, it is useful to use the new
    (<!>) operator
  - Constructing a list of properties can be problimatic, since
    Property NoInto and Property WithInfo are different types and cannot
    appear in the same list. To deal with this, "props" has been added,
    and can built up a list of properties of different types,
    using the same (&) and (!) operators that are used to build
    up a host's properties.

1 files changed, 14 insertions, 8 deletions

diff --git a/src/Propellor/Property/Postfix.hs b/src/Propellor/Property/Postfix.hs
index cdb7bdee..fbb1ea51 100644
--- a/src/Propellor/Property/Postfix.hs
+++ b/src/Propellor/Property/Postfix.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE FlexibleContexts #-}
+
 module Propellor.Property.Postfix where
 
 import Propellor
@@ -9,13 +11,13 @@ import qualified Data.Map as M
 import Data.List
 import Data.Char
 
-installed :: Property
+installed :: Property NoInfo
 installed = Apt.serviceInstalledRunning "postfix"
 
-restarted :: Property
+restarted :: Property NoInfo
 restarted = Service.restarted "postfix"
 
-reloaded :: Property
+reloaded :: Property NoInfo
 reloaded = Service.reloaded "postfix"
 
 -- | Configures postfix as a satellite system, which 
@@ -24,7 +26,7 @@ reloaded = Service.reloaded "postfix"
 -- The smarthost may refuse to relay mail on to other domains, without
 -- futher coniguration/keys. But this should be enough to get cron job
 -- mail flowing to a place where it will be seen.
-satellite :: Property
+satellite :: Property NoInfo
 satellite = check (not <$> mainCfIsSet "relayhost") setup
 	`requires` installed
   where
@@ -45,13 +47,17 @@ satellite = check (not <$> mainCfIsSet "relayhost") setup
 -- | Sets up a file by running a property (which the filename is passed
 -- to). If the setup property makes a change, postmap will be run on the
 -- file, and postfix will be reloaded.
-mappedFile :: FilePath -> (FilePath -> Property) -> Property
+mappedFile
+	:: Combines (Property x) (Property NoInfo)
+	=> FilePath
+	-> (FilePath -> Property x)
+	-> Property (CInfo x NoInfo)
 mappedFile f setup = setup f
 	`onChange` cmdProperty "postmap" [f]
 
 -- | Run newaliases command, which should be done after changing
 -- </etc/aliases>.
-newaliases :: Property
+newaliases :: Property NoInfo
 newaliases = trivial $ cmdProperty "newaliases" []
 
 -- | The main config file for postfix.
@@ -59,7 +65,7 @@ mainCfFile :: FilePath
 mainCfFile = "/etc/postfix/main.cf"
 
 -- | Sets a main.cf name=value pair. Does not reload postfix immediately.
-mainCf :: (String, String) -> Property
+mainCf :: (String, String) -> Property NoInfo
 mainCf (name, value) = check notset set
 		`describe` ("postfix main.cf " ++ setting)
   where
@@ -96,7 +102,7 @@ mainCfIsSet name = do
 --
 -- Note that multiline configurations that continue onto the next line
 -- are not currently supported.
-dedupMainCf :: Property
+dedupMainCf :: Property NoInfo
 dedupMainCf = fileProperty "postfix main.cf dedupped" dedupCf mainCfFile
 
 dedupCf :: [String] -> [String]