private readonly NarrowingLevel _maxLevel; // the maximum narrowing level allowed
public CallBinderHelper(CodeContext context, TAction action, object[] args, RuleBuilder rule)
: base(context, action)
{
ContractUtils.RequiresNotEmpty(args, "args");
_maxLevel = NarrowingLevel.All;
_args = RemoveExplicitInstanceArgument(action, args);
_rule = rule;
_test = _rule.MakeTypeTest(CompilerHelpers.GetType(Callable), 0);
}
public void MakeRule()
{
Type toType = Action.ToType;
Type knownType = CompilerHelpers.GetVisibleType(_rule.Parameters[0].Type);
// check for conversion to object first...
if (TryConvertToObject(toType, knownType))
{
_rule.AddTest(Ast.Constant(true));
return;
}
// do checks that aren't based upon strongly knowing the object's type (and don't require tests)
if (TryAllConversions(toType, knownType))
{
_rule.AddTest(Ast.Constant(true));
return;
}
// try again w/ a test for the known-type
Type type = CompilerHelpers.GetType(_arg);
_rule.AddTest(_rule.MakeTypeTest(type, 0));
if (TryAllConversions(toType, type))
{
return;
}
// finally try conversions that aren't based upon the incoming type at all but
// are last chance conversions based on the destination type
if (TryExtraConversions(toType))
{
return;
}
// no conversion is available, make an error rule.
MakeErrorTarget();
}