private RestrictedArguments GetRestrictedArgs(ApplicableCandidate selectedCandidate, IList<ApplicableCandidate> candidates, int targetSetSize) {
Debug.Assert(selectedCandidate.Method.ParameterCount == _actualArguments.Count);
int argCount = _actualArguments.Count;
var restrictedArgs = new DynamicMetaObject[argCount];
var types = new Type[argCount];
bool hasAdditionalRestrictions = false;
for (int i = 0; i < argCount; i++) {
var arg = _actualArguments[i];
if (targetSetSize > 0 && IsOverloadedOnParameter(i, argCount, candidates) ||
!selectedCandidate.GetParameter(i).Type.IsAssignableFrom(arg.Expression.Type)) {
restrictedArgs[i] = RestrictArgument(arg, selectedCandidate.GetParameter(i));
types[i] = arg.GetLimitType();
} else {
restrictedArgs[i] = arg;
}
BindingRestrictions additionalRestrictions;
if (selectedCandidate.Method.Restrictions != null && selectedCandidate.Method.Restrictions.TryGetValue(arg, out additionalRestrictions)) {
hasAdditionalRestrictions = true;
restrictedArgs[i] = new DynamicMetaObject(restrictedArgs[i].Expression, restrictedArgs[i].Restrictions.Merge(additionalRestrictions));
}
}
return new RestrictedArguments(restrictedArgs, types, hasAdditionalRestrictions);
}
private Candidate GetPreferredParameters(ApplicableCandidate one, ApplicableCandidate two, NarrowingLevel level) {
Debug.Assert(one.Method.ParameterCount == two.Method.ParameterCount);
var args = GetActualArguments();
Candidate result = Candidate.Equivalent;
for (int i = 0; i < args.Count; i++) {
Candidate preferred = GetPreferredParameter(one.GetParameter(i), two.GetParameter(i), args[i], level);
switch (result) {
case Candidate.Equivalent:
result = preferred;
break;
case Candidate.One:
if (preferred == Candidate.Two) return Candidate.Ambiguous;
break;
case Candidate.Two:
if (preferred == Candidate.One) return Candidate.Ambiguous;
break;
case Candidate.Ambiguous:
if (preferred != Candidate.Equivalent) {
result = preferred;
}
break;
default:
throw new InvalidOperationException();
}
}
// TODO: process collapsed arguments:
return result;
}
private RestrictedArguments GetRestrictedArgs(ApplicableCandidate selectedCandidate, IList<ApplicableCandidate> candidates, int targetSetSize) {
Debug.Assert(selectedCandidate.Method.ParameterCount == _actualArguments.Count);
int argCount = _actualArguments.Count;
var restrictedArgs = new DynamicMetaObject[argCount];
var types = new Type[argCount];
for (int i = 0; i < argCount; i++) {
var arg = _actualArguments[i];
if (targetSetSize > 0 && IsOverloadedOnParameter(i, argCount, candidates) ||
!selectedCandidate.GetParameter(i).Type.IsAssignableFrom(arg.Expression.Type)) {
restrictedArgs[i] = RestrictArgument(arg, selectedCandidate.GetParameter(i));
types[i] = arg.GetLimitType();
} else {
restrictedArgs[i] = arg;
}
}
return new RestrictedArguments(restrictedArgs, types);
}
