Renamed exportAccessor to exportAccessors, and removed the first stri…

…ng argument (specifying the Objective-C function name), which can be inferred instead

Demos/PhotoUploader/PhotoUploader/User.hs

@@ -50,6 +50,6 @@ decodeUser d = do
 
 exportFunc "User_initWithData" [t| UnsafeId -> IO (MaybePtr User) |] 'decodeUser
 
-exportAccessor "User_fullName" ''User 'fullName
-exportAccessor "User_username" ''User 'username
-exportAccessor "User_photoURL" ''User 'photoURL
+exportAccessors ''User 'fullName
+exportAccessors ''User 'username
+exportAccessors ''User 'photoURL

ObjectiveHaskell/Model.hs

@@ -2,7 +2,7 @@
 
 -- | Tools for building a model layer in Haskell that can interoperate with Objective-C
 module ObjectiveHaskell.Model (
-        MaybePtr, exportAccessor
+        MaybePtr, exportAccessors
     ) where
 
 import Control.Monad
@@ -12,32 +12,48 @@ import ObjectiveHaskell.MsgSend
 import ObjectiveHaskell.ObjC
 import ObjectiveHaskell.THUtils
 
--- | A pointer to a Maybe value that can be passed to and from Objective-C safely.
+-- | A pointer to a 'Maybe' value that can be passed to and from Objective-C safely.
 -- | This can be used to represent model data that may or may not exist.
 type MaybePtr a = StablePtr (Maybe a)
 
--- | Defines a function, callable from Objective-C, which applies a Haskell function to a value within a 'MaybePtr',
--- | then converts the result into an Objective-C object.
+-- | Defines two functions, callable from Objective-C, which get and set a field on a value within a 'MaybePtr'.
 -- |
--- | If the 'MaybePtr' contains 'Nothing', the exported function will return @nil@.
-exportAccessor
-    :: String   -- ^ The name of the function to export to Objective-C.
-    -> Name     -- ^ The name of the type of value stored in the 'MaybePtr'.
-    -> Name     -- ^ The name of the Haskell accessor function to apply to the value, returning a Bridged value.
-    -> Q [Dec]  -- ^ Top-level declarations to generate and export the accessor.
-
-exportAccessor str valueTypeName accessorName = do
-    let accessor = varE accessorName
+-- | For a type @Car@ and a field @model@, the following functions will be generated and exported to Objective-C:
+-- |
+-- |  * A getter @Car_model()@ which accepts a 'MaybePtr' @Car@, reads the @model@ field and converts the result into an
+-- |    Objective-C object. If the 'MaybePtr' contains 'Nothing', @nil@ is returned.
+-- |  * A setter @Car_setModel()@ which accepts a 'MaybePtr' @Car@ and a new value for the @model@ field, and returns a
+-- |    new 'MaybePtr' @Car@, where the field in the @Car@ value has been set to the given value.
+exportAccessors
+    :: Name     -- ^ The name of the type of value stored in the 'MaybePtr'.
+    -> Name     -- ^ The name of the record field to access or set in the value, which should hold a 'Bridged' value.
+    -> Q [Dec]  -- ^ Top-level declarations to generate and export the accessors.
+
+exportAccessors typeName field = do
+    let getter = (nameBase typeName) ++ "_" ++ (nameBase field)
+        t = conT typeName
+
+    -- TODO: export setter
+    exportGetter getter t field
+
+exportGetter
+    :: String   -- ^ The name of the function to export.
+    -> Q Type   -- ^ The type of value stored in the 'MaybePtr'.
+    -> Name     -- ^ The name of the record field to access.
+    -> Q [Dec]
+
+exportGetter objcName t field = do
+    hsName <- newName $ "_hs_" ++ objcName
+    ft <- [t| MaybePtr $t -> IO UnsafeId |]
+
+    let getter = varE field
         arg = mkName "ptr"
-        valCon = conT valueTypeName
 
-    name <- newName $ "_hs_" ++ str
-    ft <- [t| MaybePtr $valCon -> IO UnsafeId |]
+        decl = ForeignD $ ExportF CCall objcName hsName ft
 
-    let externDecl = ForeignD $ ExportF CCall str name ft
-    funcDef <- singleClauseFunc name [arg] [| do
+    def <- singleClauseFunc hsName [arg] [| do
                 ptr <- deRefStablePtr $(varE arg)
-                obj <- maybe nil (toObjC . $accessor) ptr
+                obj <- maybe nil (toObjC . $getter) ptr
                 autorelease obj |]
 
-    return [externDecl, funcDef]
+    return [decl, def]