Add Error module.

Also add the importCFString/importCFStringAs functions.

CoreFoundation/CoreFoundation.cabal

@@ -41,6 +41,7 @@ Library
         System.CoreFoundation.Base
         System.CoreFoundation.Array
         System.CoreFoundation.Data
+        System.CoreFoundation.Error
         System.CoreFoundation.Dictionary
         System.CoreFoundation.Number
         System.CoreFoundation.RunLoop

CoreFoundation/System/CoreFoundation.hs

@@ -2,6 +2,7 @@ module System.CoreFoundation(
             module System.CoreFoundation.Base,
             module System.CoreFoundation.Array,
             module System.CoreFoundation.Data,
+            module System.CoreFoundation.Error,
             module System.CoreFoundation.Dictionary,
             module System.CoreFoundation.Number,
             module System.CoreFoundation.RunLoop,
@@ -12,6 +13,7 @@ module System.CoreFoundation(
 import System.CoreFoundation.Base
 import System.CoreFoundation.Array
 import System.CoreFoundation.Data
+import System.CoreFoundation.Error
 import System.CoreFoundation.Dictionary
 import System.CoreFoundation.Number
 import System.CoreFoundation.RunLoop

CoreFoundation/System/CoreFoundation/Error.chs

@@ -0,0 +1,82 @@
+-- | Interface to CoreFoundation's @CFError@ C type.
+-- It is toll-free bridged with the @NSData@ type.
+module System.CoreFoundation.Error (
+            -- * The Error type
+            Error,
+            ErrorRef,
+            newError,
+            -- * Error properties
+            errorDescription,
+            errorFailureReason,
+            errorRecoverySuggestion,
+            userInfo,
+            errorDomain,
+            errorCode,
+            -- * Error domains
+            domainPOSIX,
+            domainOSStatus,
+            domainMach,
+            domainCocoa,
+            -- * User info keys
+            localizedDescriptionKey,
+            localizedFailureReasonKey,
+            localizedRecoverySuggestionKey,
+            descriptionKey,
+            underlyingErrorKey,
+            ) where
+
+import Foreign
+import Foreign.C
+
+import Prelude hiding (String)
+
+import System.CoreFoundation.Base
+import System.CoreFoundation.Dictionary
+import System.CoreFoundation.String as CF
+import System.CoreFoundation.Internal.TH
+
+#include <CoreFoundation/CoreFoundation.h>
+
+declareCFType "Error"
+
+importCFStringAs "kCFErrorLocalizedDescriptionKey" "localizedDescriptionKey"
+importCFStringAs "kCFErrorLocalizedFailureReasonKey" "localizedFailureReasonKey"
+importCFStringAs "kCFErrorLocalizedRecoverySuggestionKey" "localizedRecoverySuggestionKey"
+importCFStringAs "kCFErrorDescriptionKey" "descriptionKey"
+importCFStringAs "kCFErrorUnderlyingErrorKey" "underlyingErrorKey"
+
+importCFStringAs "kCFErrorDomainPOSIX" "domainPOSIX"
+importCFStringAs "kCFErrorDomainOSStatus" "domainOSStatus"
+importCFStringAs "kCFErrorDomainMach" "domainMach"
+importCFStringAs "kCFErrorDomainCocoa" "domainCocoa"
+
+{#fun CFErrorCreate as newError
+    { withDefaultAllocator- `AllocatorPtr'
+    ,  withObject* `String'
+    , `Int'
+    , maybeWithObject* `Maybe Dictionary'
+    } -> `Error' getOwned* #}
+
+maybeWithObject Nothing = ($ nullPtr)
+maybeWithObject (Just o) = withObject o
+
+{#fun pure CFErrorCopyDescription as errorDescription
+    { withObject* `Error' } -> `String' getAndRetain* #}
+-- The docs say that the CFErrorCopyDescription will never return NULL.
+
+{#fun pure CFErrorCopyFailureReason as errorFailureReason
+    { withObject* `Error' } -> `Maybe String' maybeGetAndRetain* #}
+
+{#fun pure CFErrorCopyRecoverySuggestion as errorRecoverySuggestion
+    { withObject* `Error' } -> `Maybe String' maybeGetAndRetain* #}
+
+{#fun pure CFErrorCopyUserInfo as userInfo
+    { withObject* `Error' } -> `Maybe Dictionary' maybeGetAndRetain* #}
+
+{#fun pure CFErrorGetDomain as errorDomain
+    { withObject* `Error' } -> `String' getAndRetain* #}
+
+{#fun pure CFErrorGetCode as errorCode
+    { withObject* `Error' } -> `CFIndex' id #} 
+
+

CoreFoundation/System/CoreFoundation/String.chs

@@ -12,6 +12,9 @@ module System.CoreFoundation.String(
                 -- * Conversion to/from 'Text'
                 newStringFromText,
                 getText,
+                -- * Foreign import of string constants
+                importCFString,
+                importCFStringAs,
                 ) where
 
 -- TODO: 
@@ -38,6 +41,7 @@ import qualified Prelude
 import qualified Data.Text as Text
 import qualified Data.Text.Encoding as Encoding
 import Data.Text.Foreign (useAsPtr, fromPtr)
+import Language.Haskell.TH
 
 #include <CoreFoundation/CoreFoundation.h>
 
@@ -102,3 +106,20 @@ getText s = do
 -- | Extract a 'Prelude.String' copy of the given @CoreFoundation.String@.
 getChars :: String -> IO Prelude.String
 getChars = fmap Text.unpack . getText
+
+
+importCFStringAs :: Prelude.String -> Prelude.String -> Q [Dec]
+importCFStringAs foreignStr nameStr = do
+    ptrName <- newName (nameStr ++ "Ptr")
+    let name = mkName nameStr
+    ptrType <- [t| Ptr CFTypeRef |]
+    expr <- [| unsafePerformIO $ peek $(varE ptrName) >>= getAndRetain |]
+    return
+        [ ForeignD $ ImportF CCall Safe ("&" ++ foreignStr) ptrName ptrType
+        , SigD name (ConT ''String)
+        , FunD name [Clause [] (NormalB expr) []]
+        ]
+
+
+importCFString :: Prelude.String -> Q [Dec]
+importCFString s = importCFStringAs s s