entity A {
	attr a
}

entity B {
	attr a
	attr r : A
}

entity C {
	attr r : B
	
	set r = 3	// works
	set r.a = 4	// ?
	set r.r.a = 5	// ?
}

Model:
	(entities += Entity)*;
	
Entity:
	'entity' name = ID '{'
		(attributes += Attribute)*
		(settings += Setting)*
	'}';

Attribute:
	'attr' name = ID (':' type = [Entity])?;

Setting:
	'set' attributePath = [Attribute|FQN] '=' value = INT;
//	'set' path += [Attribute] ('.' path += [Attribute])* '=' value = INT; // Alternative approach

FQN:
	ID ('.' ID)*;