class Mapping::Model

def self.map(klass, &block)

Add a mapping from a given input class to a specific block. 
def self.map(klass, &block)
	method_name = self.method_for_mapping(klass)
	define_method(method_name, &block)
end

def self.map_identity(*klasses)

Sometimes you just want to map things to themselves (the identity function). This makes it convenient to specify a lot of identity mappings. 
def self.map_identity(*klasses)
	klasses.each do |klass|
		self.map(klass) {|value| value}
	end
end

def self.method_for_mapping(klass)

This function generates mapping names like `map_Array` and `map_Hash` which while a bit non-standard are perfectly fine for our purposes and this never really needs to leak. 
def self.method_for_mapping(klass)
	PREFIX + klass.name.gsub(/::/, '_')
end

def self.unmap(klass)

Remove a mapping, usually an inherited one, which you don't want. 
def self.unmap(klass)
	method_name = self.method_for_mapping(klass)
	undef_method(method_name)
end

def map(root, *args)

The primary function, which maps an input object to an output object. 
def map(root, *args)
	method_name = self.method_for_mapping(root)
	
	self.send(method_name, root, *args)
end

def method_for_mapping(object)

Get the name of the method for mapping the given object. 
def method_for_mapping(object)
	self.class.method_for_mapping(object.class)
end