[hoc-users] what to use for NULL?

[Thorsten S. <tho...@we...>]

Hi,

I'm just beginning to use HOC and so far I'm very happy (I did have to  
make some adjustments to account for GHC 6.10 and a custom  
installation location of Xcode 3).

Currently I'm stuck on calling - 
beginSheetForDirectory:file:types:modalForWindow:modalDelegate:didEndSelector:contextInfo 
: because I don't know what to pass for (coid *)contextInfo. I assumed  
that nullPtr would be correct, but I get a type error which I do not  
understand.

My code:

panel <- _NSOpenPanel # openPanel
panel #  
beginSheetForDirectoryFileTypesModalForWindowModalDelegateDidEndSelectorContextInfo
	nil
	nil
	nil
	window
	modalDelegate
	(getSelectorForName selector)
	nullPtr

The type error:

     Couldn't match expected type `GHC.Ptr.Ptr
                                     HOC-1.0:HOC.Base.ObjCObject'
            against inferred type  
`HOC-1.0:HOC.Arguments.EvilDummyForUnit'
     When using functional dependencies to combine
       ObjCArgument () HOC-1.0:HOC.Arguments.EvilDummyForUnit,
         arising from the dependency `a -> b'
         in the instance declaration at <no location info>
       ObjCArgument () (GHC.Ptr.Ptr HOC-1.0:HOC.Base.ObjCObject),
         arising from a use of  
` 
beginSheetForDirectoryFileTypesModalForWindowModalDelegateDidEndSelectorContextInfo 
'

Any help will be greatly appreciated!

Best regards
Thorsten