Monkeypatching and Dynamic Methods

How is this different from monkeypatching in e.g. Python, Ruby?

many languages that do OO have that; Perl, Smalltalk, Objective-C, f.e.. But this seems more like monkey-patching.

What is a typical use case for dynamically adding methods to a class?

A lot of languages have constructs that allow changing an attribute into a method call transparently (@property in python and D)

It's like monkey patching in Ruby. It can be used for good and for evil.

Monkeypatching is programatically adding a method to a class at runtime.

Agree with youAs for method_missing, what do you miss from IDynamicMetaObjectProvider and related classes?

In C# this is called extension methods: monkey-patching (for methods) without polluting the global scope.

It isn't so odd in Ruby. Ruby has always been a duck typing land. If it quacks, it is a duck. There's even a method missing handler so you can respond to any method call whatsoever. People can and do add methods directly to even built-in classes as well, the equivalent of modifying the class prototype in Javascript. So method calls are considered more messages in Ruby and saying a class will respond differently to a message after it has more data about what it is, a certain blog for example, isn

you can view it as serving the same role as universal function call syntax, the latter being a feature in some other languages that rewrites `a.f(x)` to `f(a, x)` if `a` doesn't have a method `f`. in ruby you can just add the method to `a`'s class directly, but the idea is the same - you're adding some user defined function that is closely related to the type of `a`, and you're using method call syntax because that reads nicely.