Syntactically invalid EFactory example which causes the OutOfMemoryError at org.eclipse.xtext.ui.editor.syntaxcoloring reported on the Xtext Forum

badSomeFamilies.efactory

family.City {
	families += family.Family Flintstones {
		
		members = [
			family.Person Fred {
			age = 45
			}
		]
		
		members += family.Person Fred {
			age = 45
		}
		members += family.Person Wilma {
			gender = :female
		}
		pet = Dino
		
	}
	
	animals += family.Dinosaur Dino {
		height = 1374
	}
	
}

family.xcore

package family

import java.lang.String

class Person {
	String name
	Gender gender
	Integer age 
	refers Person[] friends
	refers Person bestFriend		
}

class Family {
	String name
	String address
	contains Person[] members
	refers Animal pet
}

abstract class Animal {
} 

class Dinosaur extends Animal {
	String name
	int height
}

enum Gender {
	female, male
}

class City {
	contains Family[] families
	contains Animal[] animals
}