{--
JVM-Bridge -- bridge from FP languages and others to the Java VM
Copyright (C) 2001 Ashley Yakeley <ashley@semantic.org>

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
--}

module Foreign.JavaVM.VM.Witness where
{
	import Foreign.JavaVM.VM.Ref;
	import Platform.JavaVM;
	import Data.Witness;

	data VMType t where
	{
		Tprimitive :: PrimitiveType t -> VMType t;
		Tref :: VMType VMRef;
	};
	
	instance Witness VMType where
	{
		withWitness f t@(Tprimitive Tboolean)	= f t;
		withWitness f t@(Tprimitive Tbyte)		= f t;
		withWitness f t@(Tprimitive Tchar)		= f t;
		withWitness f t@(Tprimitive Tshort)		= f t;
		withWitness f t@(Tprimitive Tint)		= f t;
		withWitness f t@(Tprimitive Tlong)		= f t;
		withWitness f t@(Tprimitive Tfloat)		= f t;
		withWitness f t@(Tprimitive Tdouble)	= f t;
		withWitness f t@Tref					= f t;
	};
	
	instance TotalWitness VMType where
	{
		matchWitnessF (Tprimitive ta) (Tprimitive tb) = matchWitnessF ta tb;
		matchWitnessF Tref Tref = Just id;
		matchWitnessF _ _ = Nothing;
	};
	
	instance Is VMType Jboolean where
	{
		witness = Tprimitive Tboolean;
	};
	
	instance Is VMType Jbyte where
	{
		witness = Tprimitive Tbyte;
	};
	
	instance Is VMType Jchar where
	{
		witness = Tprimitive Tchar;
	};
	
	instance Is VMType Jshort where
	{
		witness = Tprimitive Tshort;
	};
	
	instance Is VMType Jint where
	{
		witness = Tprimitive Tint;
	};
	
	instance Is VMType Jlong where
	{
		witness = Tprimitive Tlong;
	};
	
	instance Is VMType Jfloat where
	{
		witness = Tprimitive Tfloat;
	};
	
	instance Is VMType Jdouble where
	{
		witness = Tprimitive Tdouble;
	};
	
	instance Is VMType VMRef where
	{
		witness = Tref;
	};

	javaToJNIValueType :: ValueType -> AnyWitness VMType;
	javaToJNIValueType MkBooleanType= AnyWitness (Tprimitive Tboolean);
	javaToJNIValueType MkByteType	= AnyWitness (Tprimitive Tbyte);
	javaToJNIValueType MkCharType	= AnyWitness (Tprimitive Tchar);
	javaToJNIValueType MkShortType	= AnyWitness (Tprimitive Tshort);
	javaToJNIValueType MkIntType	= AnyWitness (Tprimitive Tint);
	javaToJNIValueType MkLongType	= AnyWitness (Tprimitive Tlong);
	javaToJNIValueType MkFloatType	= AnyWitness (Tprimitive Tfloat);
	javaToJNIValueType MkDoubleType	= AnyWitness (Tprimitive Tdouble);
	javaToJNIValueType _			= AnyWitness Tref;

	data VMReturnType t where
	{
		Tvalue :: VMType t -> VMReturnType t;
		Tvoid :: VMReturnType Jvoid;
	};
	
	instance Witness VMReturnType where
	{
		withWitness f t@(Tvalue (Tprimitive Tboolean))	= f t;
		withWitness f t@(Tvalue (Tprimitive Tbyte))		= f t;
		withWitness f t@(Tvalue (Tprimitive Tchar))		= f t;
		withWitness f t@(Tvalue (Tprimitive Tshort))	= f t;
		withWitness f t@(Tvalue (Tprimitive Tint))		= f t;
		withWitness f t@(Tvalue (Tprimitive Tlong))		= f t;
		withWitness f t@(Tvalue (Tprimitive Tfloat))	= f t;
		withWitness f t@(Tvalue (Tprimitive Tdouble))	= f t;
		withWitness f t@(Tvalue Tref)					= f t;
		withWitness f t@Tvoid							= f t;
	};
	
	instance TotalWitness VMReturnType where
	{
		matchWitnessF (Tvalue ta) (Tvalue tb) = matchWitnessF ta tb;
		matchWitnessF Tvoid Tvoid = Just id;
		matchWitnessF _ _ = Nothing;
	};
	
	instance Is VMReturnType Jboolean where
	{
		witness = Tvalue (Tprimitive Tboolean);
	};
	
	instance Is VMReturnType Jbyte where
	{
		witness = Tvalue (Tprimitive Tbyte);
	};
	
	instance Is VMReturnType Jchar where
	{
		witness = Tvalue (Tprimitive Tchar);
	};
	
	instance Is VMReturnType Jshort where
	{
		witness = Tvalue (Tprimitive Tshort);
	};
	
	instance Is VMReturnType Jint where
	{
		witness = Tvalue (Tprimitive Tint);
	};
	
	instance Is VMReturnType Jlong where
	{
		witness = Tvalue (Tprimitive Tlong);
	};
	
	instance Is VMReturnType Jfloat where
	{
		witness = Tvalue (Tprimitive Tfloat);
	};
	
	instance Is VMReturnType Jdouble where
	{
		witness = Tvalue (Tprimitive Tdouble);
	};
	
	instance Is VMReturnType VMRef where
	{
		witness = Tvalue Tref;
	};
	
	instance Is VMReturnType Jvoid where
	{
		witness = Tvoid;
	};

	javaToJNIReturnType :: ReturnType -> AnyWitness VMReturnType;
	javaToJNIReturnType MkVoidType		= AnyWitness Tvoid;
	javaToJNIReturnType (MkValueType t)	= (\(AnyWitness w) -> AnyWitness (Tvalue w)) (javaToJNIValueType t);
}