public override Type[] InferMethodArguments(ParseContext ec, MethodBase method)
{
Type[] method_generic_args = method.GetGenericArguments();
TypeInferenceContext context = new TypeInferenceContext(method_generic_args);
if (!context.UnfixedVariableExists)
{
return(Type.EmptyTypes);
}
ParametersCollection pd = TypeManager.GetParameterData(method);
if (!InferInPhases(ec, context, pd))
{
return(null);
}
return(context.InferredTypeArguments);
}
//
// Implements method type arguments inference
//
bool InferInPhases(ParseContext ec, TypeInferenceContext tic, ParametersCollection methodParameters)
{
int paramsArgumentsStart;
if (methodParameters.HasParams)
{
paramsArgumentsStart = methodParameters.Count - 1;
}
else
{
paramsArgumentsStart = arg_count;
}
Type[] ptypes = methodParameters.Types;
//
// The first inference phase
//
Type methodParameter = null;
for (int i = 0; i < arg_count; i++)
{
Argument a = arguments[i];
if (a == null)
{
continue;
}
if (i < paramsArgumentsStart)
{
methodParameter = methodParameters.Types[i];
}
else if (i == paramsArgumentsStart)
{
if (arg_count == paramsArgumentsStart + 1 && TypeManager.HasElementType(a.Value.Type))
{
methodParameter = methodParameters.Types[paramsArgumentsStart];
}
else
{
methodParameter = methodParameters.Types[paramsArgumentsStart].GetElementType();
}
ptypes = (Type[])ptypes.Clone();
ptypes[i] = methodParameter;
}
//
// When a lambda expression, an anonymous method
// is used an explicit argument type inference takes a place
//
var am = a.Value as LambdaExpression;
if (am != null)
{
if (am.ExplicitTypeInference(ec, tic, methodParameter))
{
--score;
}
continue;
}
if (a.IsByRef)
{
score -= tic.ExactInference(a.Value.Type, methodParameter);
continue;
}
if (a.Value.Type == TypeManager.CoreTypes.Null)
{
continue;
}
if (TypeManager.IsValueType(methodParameter))
{
score -= tic.LowerBoundInference(a.Value.Type, methodParameter);
continue;
}
//
// Otherwise an output type inference is made
//
score -= tic.OutputTypeInference(ec, a.Value, methodParameter);
}
//
// Part of the second phase but because it happens only once
// we don't need to call it in cycle
//
var fixedAny = false;
if (!tic.FixIndependentTypeArguments(ec, ptypes, ref fixedAny))
{
return(false);
}
return(DoSecondPhase(ec, tic, ptypes, !fixedAny));
}