You can compile expression trees to use void methods without any arguments as event handlers for events of any type. To accommodate other event handler types, you have to map the event handler’s parameters to the events somehow. using System; using System.Linq; using System.Linq.Expressions; using System.Reflection; class ExampleEventArgs : EventArgs { public int IntArg {get; … Read more
You have to specify which method you want: class SomeType { void Foo(int size, string bar) { } void Foo() { } } SomeType obj = new SomeType(); // call with int and string arguments obj.GetType() .GetMethod(“Foo”, new Type[] { typeof(int), typeof(string) }) .Invoke(obj, new object[] { 42, “Hello” }); // call without arguments obj.GetType() … Read more
I think this should point you towards the right direction: import java.beans.* for (PropertyDescriptor pd : Introspector.getBeanInfo(Foo.class).getPropertyDescriptors()) { if (pd.getReadMethod() != null && !”class”.equals(pd.getName())) System.out.println(pd.getReadMethod().invoke(foo)); } Note that you could create BeanInfo or PropertyDescriptor instances yourself, i.e. without using Introspector. However, Introspector does some caching internally which is normally a Good Thing ™. If you’re … Read more
From the documentation for Field.set: If the underlying field is final, the method throws an IllegalAccessException unless setAccessible(true) has succeeded for this field and this field is non-static. So at first it seems that you are out of luck, since File.separatorChar is static. Surprisingly, there is a way to get around this: simply make the … Read more
Apache Commons Lang has a utility method to do this (ClassUtils.primitiveToWrapper()), which will be just as ugly under the covers, but at least you can pretend it’s nice.
Yes, it’s possible. The trick is to start from a pointer to the type (whose value can be a typed nil, that’s perfectly OK), and then use Type.Elem() to get the reflect.Type descriptor of the pointed type (the base type). See some examples: t := reflect.TypeOf((*int)(nil)).Elem() fmt.Println(t) t = reflect.TypeOf((*http.Request)(nil)).Elem() fmt.Println(t) t = reflect.TypeOf((*os.File)(nil)).Elem() fmt.Println(t) … Read more
Get the methods with Type.GetMethods, then use MethodInfo.IsSpecialName to discover operators, conversions etc. Here’s an example: using System; using System.Reflection; public class Foo { public static Foo operator +(Foo x, Foo y) { return new Foo(); } public static implicit operator string(Foo x) { return “”; } } public class Example { public static void … Read more
Yup, simply use send (or, better yet, public_send) like so: arg1.public_send(op, arg2) This works because most operators in Ruby (including +, -, *, /, and more) simply call methods. So 1 + 2 is the same as 1.+(2). You may also want to whitelist op if it’s user input, e.g. %w[+ – * /].include?(op), as … Read more
You cannot. There is no watch-on-modification hook built into Java itself. Obviously, you could do polling, though. But then it won’t be “live”. AspectJ may allow such a think, but I’m not sure whether it holds for primitive variables, or only when you are using getters and setters. The clean Java-way is to make the … Read more
I made an example of what you want that you can see at my blog site. In this is case it’s a JSON serializer that works with nested structs. It uses a ‘more Boost’ solution since I saw it in the Boost.Serialization library. (See also below and live on Coliru.) The solution uses Fusion Sequence … Read more