//
// Implements method type arguments inference
//
bool InferInPhases (EmitContext ec, TypeInferenceContext tic, AParametersCollection methodParameters)
{
int params_arguments_start;
if (methodParameters.HasParams) {
params_arguments_start = methodParameters.Count - 1;
} else {
params_arguments_start = arg_count;
}
Type [] ptypes = methodParameters.Types;
//
// The first inference phase
//
Type method_parameter = null;
for (int i = 0; i < arg_count; i++) {
Argument a = (Argument) arguments [i];
if (i < params_arguments_start) {
method_parameter = methodParameters.Types [i];
} else if (i == params_arguments_start) {
if (arg_count == params_arguments_start + 1 && TypeManager.HasElementType (a.Type))
method_parameter = methodParameters.Types [params_arguments_start];
else
method_parameter = TypeManager.GetElementType (methodParameters.Types [params_arguments_start]);
ptypes = (Type[]) ptypes.Clone ();
ptypes [i] = method_parameter;
}
//
// When a lambda expression, an anonymous method
// is used an explicit argument type inference takes a place
//
AnonymousMethodExpression am = a.Expr as AnonymousMethodExpression;
if (am != null) {
if (am.ExplicitTypeInference (tic, method_parameter))
--score;
continue;
}
if (a.Expr is NullLiteral)
continue;
//
// Otherwise an output type inference is made
//
score -= tic.OutputTypeInference (ec, a.Expr, method_parameter);
}
//
// Part of the second phase but because it happens only once
// we don't need to call it in cycle
//
bool fixed_any = false;
if (!tic.FixIndependentTypeArguments (ptypes, ref fixed_any))
return false;
return DoSecondPhase (ec, tic, ptypes, !fixed_any);
}
bool DoSecondPhase (EmitContext ec, TypeInferenceContext tic, Type[] methodParameters, bool fixDependent)
{
bool fixed_any = false;
if (fixDependent && !tic.FixDependentTypes (ref fixed_any))
return false;
// If no further unfixed type variables exist, type inference succeeds
if (!tic.UnfixedVariableExists)
return true;
if (!fixed_any && fixDependent)
return false;
// For all arguments where the corresponding argument output types
// contain unfixed type variables but the input types do not,
// an output type inference is made
for (int i = 0; i < arg_count; i++) {
// Align params arguments
Type t_i = methodParameters [i >= methodParameters.Length ? methodParameters.Length - 1: i];
if (!TypeManager.IsDelegateType (t_i)) {
if (TypeManager.DropGenericTypeArguments (t_i) != TypeManager.expression_type)
continue;
t_i = t_i.GetGenericArguments () [0];
}
MethodInfo mi = Delegate.GetInvokeMethod (t_i, t_i);
Type rtype = mi.ReturnType;
#if MS_COMPATIBLE
// Blablabla, because reflection does not work with dynamic types
Type[] g_args = t_i.GetGenericArguments ();
rtype = g_args[rtype.GenericParameterPosition];
#endif
if (tic.IsReturnTypeNonDependent (mi, rtype))
score -= tic.OutputTypeInference (ec, ((Argument) arguments [i]).Expr, t_i);
}
return DoSecondPhase (ec, tic, methodParameters, true);
}
bool DoSecondPhase (ResolveContext ec, TypeInferenceContext tic, TypeSpec[] methodParameters, bool fixDependent)
{
bool fixed_any = false;
if (fixDependent && !tic.FixDependentTypes (ec, ref fixed_any))
return false;
// If no further unfixed type variables exist, type inference succeeds
if (!tic.UnfixedVariableExists)
return true;
if (!fixed_any && fixDependent)
return false;
// For all arguments where the corresponding argument output types
// contain unfixed type variables but the input types do not,
// an output type inference is made
for (int i = 0; i < arg_count; i++) {
// Align params arguments
TypeSpec t_i = methodParameters [i >= methodParameters.Length ? methodParameters.Length - 1: i];
if (!TypeManager.IsDelegateType (t_i)) {
if (t_i.GetDefinition () != TypeManager.expression_type)
continue;
t_i = TypeManager.GetTypeArguments (t_i) [0];
}
var mi = Delegate.GetInvokeMethod (ec.Compiler, t_i);
TypeSpec rtype = mi.ReturnType;
if (tic.IsReturnTypeNonDependent (ec, mi, rtype))
score -= tic.OutputTypeInference (ec, arguments [i].Expr, t_i);
}
return DoSecondPhase (ec, tic, methodParameters, true);
}
