Map 'WordXY' and 'IntXY' types to 'uintXY_t' and 'intXY_t'

[sboosali]

this Haskell function (in Events.hs):

press flags keys = $(objc ['flags :> [t|Word64|], 'keys :> [t|String|]] $ void [cexp|
 NSLog(@"%qu %@", flags, keys)
|])

causes this error, from the generated C (in Events_objc.h):

./Events_objc.h:10:37: error: unknown type name 'HsStablePtr'
void cwrapper_1627417270_1627417271(HsStablePtr flags_1627417272,

maybe this is because Events_objc.m imports "HsFFI.h", but Events_objc.h does not? maybe Word64 causes issues? My makefile could be wrong. or I could be using the hints wrongly, I'm trying to pass a unsigned integer.

I pushed a branch here: https://github.com/sboosali/Haskell-DragonNaturallySpeaking/tree/issue

relevant files:

Makefile
Events.hs
Main.hs
Events_objc.h
Events_objc.m

[mchakravarty]

There are two things going on here: firstly, language-c-inline hasn't got marshalling for Word64 predefined. (It's easy to add that and I will use this ticket as a feature request to add marshalling for the WordXY and IntXY types.) Whenever you try to call a foreign function with a Haskell type that language-c-inline doesn't know how to marshall, it represents that type as a HSStablePtr in C (i.e., as a GC-safe pointer to the Haskell value inside the Haskell heap).

Secondly, as you already suspected, the definition of HSStablePtr comes from HsFFI.h and as that isn't included into the header, you got the above error message.

As a workaround (until I have implemented support for Word64), may I suggest to use the C types pre-defined by the Haskell C FFI: http://hackage.haskell.org/package/base-4.7.0.1/docs/Foreign-C-Types.html

[sboosali]

Thanks!

Foreign.C.Types CULLong was the first thing I tried, but it gave that
error, expecting a pointer (I will double check this). That's why I then
tried the wrapped type Word64.

The Marshall array example helped some, I'm still thinking about the marshaling.

Is haskellToCTypeMap ObjC in Language.C.Inline.ObjC.Marshal the full set
of predefined supported types, for marshaling from Haskell to Objective-C?

On Sun, Oct 5, 2014 at 11:44 PM, Manuel M T Chakravarty <
notifications@github.com> wrote:

There are two things going on here: firstly, language-c-inline hasn't got
marshalling for Word64 predefined. (It's easy to add that and I will use
this ticket as a feature request to add marshalling for the WordXY and
IntXY types.) Whenever you try to call a foreign function with a Haskell
type that language-c-inline doesn't know how to marshall, it represents
that type as a HSStablePtr in C (i.e., as a GC-safe pointer to the
Haskell value inside the Haskell heap).

Secondly, as you already suspected, the definition of HSStablePtr comes
from HsFFI.h and as that isn't included into the header, you got the
above error message.

As a workaround (until I have implemented support for Word64), may I
suggest to use the C types pre-defined by the Haskell C FFI:
http://hackage.haskell.org/package/base-4.7.0.1/docs/Foreign-C-Types.html

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Boosalis

[mchakravarty]

haskellToCTypeMap is the fill set of unparameterised types that have predefined marshalling. Further types, such as Maybe a are covered in haskellTypeToCType.