[hoc-cvs] hoc/docs Creating_an_Objective-C_Class_in_Haskell.pod,1.2,1.3

[Wolfgang T. <wth...@us...>]

Update of /cvsroot/hoc/hoc/docs
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv6041

Modified Files:
	Creating_an_Objective-C_Class_in_Haskell.pod 
Log Message:
Add a short section about "Declaring your own Selectors"


Index: Creating_an_Objective-C_Class_in_Haskell.pod
===================================================================
RCS file: /cvsroot/hoc/hoc/docs/Creating_an_Objective-C_Class_in_Haskell.pod,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -d -r1.2 -r1.3
--- Creating_an_Objective-C_Class_in_Haskell.pod	7 May 2004 09:15:18 -0000	1.2
+++ Creating_an_Objective-C_Class_in_Haskell.pod	10 May 2004 21:15:28 -0000	1.3
@@ -190,8 +190,38 @@
       ])
 
 
+=head2 Declaring your own Selectors
+
+The I<HaskellDocument> class in the above example only
+implemented methods whose types were already known because the
+selector was already defined somewhere in Cocoa. If you've just
+used InterfaceBuilder to place a small button labeled with the
+Greek letter Pi in the lower-left corner of your window and
+connected it to a method named C<smallPiClicked:>, then you'll
+need to declare that selector yourself using the
+C<declareSelector> template function, which has the following
+type:
+
+  :: String  -- ^ The Objective-C selector name
+  -> TypeQ   -- ^ The method's type signature
+  -> Q [Dec] -- ^ Code which produces a Haskell declaration
 
+So for the C<smallPiClicked:> selector you might write:
+
+  $(declareSelector "smallPiClicked:" [t| forall a. ID a -> IO () |]
+
+The Objective-C selector name "smallPiClicked:" will be
+automatically mangled to C<smallPiClicked>. If you don't like
+this, you can use C<declareRenamedSelector> instead:
 
+  $(declareRenamedSelector "smallPiClicked:" "haskellNameForThisSelector"
+                           [t| forall a. ID a -> IO () |])
+
+Due to a limitation of Template Haskell, you cannot put this
+declaration in the same module as your C<exportClass>
+declaration. This is because identifiers declared by Template
+Haskell "splices" are not available to other splices within the
+same module.
 
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