Re: [hoc-users] Pointer arguments to methods

[Wolfgang T. <wol...@gm...>]

> I notice that ifgen doesn't handle out-parameters, such as the
> increasingly-common (NSError**) idiom.  (Examples include NSDocument's
> readFromURL:ofType:error: and writeToURL:ofType:error:.)  Is that just
> a limitation of ifgen, or does the HOC runtime also need to be
> extended to handle that case?  Either way, I'm happy to help if I can.

I think there should be a certain division of labour here between  
ifgen and libHOC; the latter should provide some more variants of  
declareSelector which support smarter argument marshalling, while  
ifgen has to recognise the relevant situations (maybe aided by the  
binding-script) and generate calls to the appropriate things.

So we first need to figure out what kind of situations we want to  
handle:

- (BOOL)writeToFile:(NSString *)path options:(unsigned) 
writeOptionsMask error:(NSError **)errorPtr;

What should be the Haskell type of this?

NSString a -> CUInt -> (Bool, NSError ()) ?

Next, we should decide what TH macros libHOC should provide to import  
selectors with those types, and finally we need to decide in what  
situations ifgen can recognise these automatically, and when it will  
need help from the binding-script.

My brain is all spent for today... ideas are welcome.

Cheers,

Wolfgang