private static StringTransformer Guard <TVal>(GuardedValueTransformer <TVal> transformer)
{
return((t, v) =>
{
if (!typeof(TVal).IsAssignableFrom(t))
{
return null;
}
return transformer((TVal)v);
});
}
internal static void RegisterFilter <TVal>(GuardedValueTransformer <TVal> filter)
{
if (Transformers.ContainsKey(typeof(TVal)))
{
Transformers[typeof(TVal)] = Guard(filter);
}
else
{
Transformers.Add(typeof(TVal), Guard(filter));
}
}
private static Transformer Guard <TVal>(GuardedValueTransformer <TVal> transformer)
{
return((t, v) => !typeof(TVal).GetTypeInfo().IsAssignableFrom(t) ? null : transformer((TVal)v));
}
public static void RegisterFilter <TVal>(GuardedValueTransformer <TVal> filter)
{
Transformers.Add(Guard <TVal>(filter));
}